Frequently Asked Audio Questions - Updated 18th Aug 2016

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Chris Hocking

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Frequently Asked Audio Questions - Updated 18th Aug 2016

PostSat Nov 09, 2013 7:17 am

For your convenience, I have arranged a listing of some of the more commonly asked questions regarding the Blackmagic Camera's audio functionality.

If you can't find the answer below, before you post a question, give the Search function a try, if for no other reason than to refine the scope of your question. Most of the time you'll find your question has already been answered. Reading other responses will also serve as good "research" for your own question.

If you can't find your answer via search, then no problem, post away! But if you're too lazy to search, then don't be surprised if your post doesn't get too many replies!

Finally... PLEASE use your full name when posting. The idea of this rule, which has existed since the creation of these forums, is that users who can be clearly identified will be more respectful than those who remain anonymous.

Happy Shooting!

P.S. There's a great thread here where Johannes Hoffmann chats about affordable and reasonable audio solutions for the BMCC.


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Please be aware that this thread is not associated with or endorsed by Blackmagic Design.

If you notice a mistake or something that's out-dated please let me know.

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GENERAL ADVICE:


READ THE MANUAL:
The manauls for all of Blackmagic's products are actually REALLY detailed, and REALLY easy to read. We highly recommend checking them out as a first point of call.


PHANTOM POWER:
It is standard practice to always plug in your XLR cable before switching phantom power on. Phantom power can also take quite a while to discharge after switching phantom power off on URSA Mini. Please be aware that you should wait a few minutes when switching off phantom power before plugging in any other microphones or XLR audio equipment.


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BLACKMAGIC URSA MINI:


Can I record decent audio on the Blackmagic Ursa Mini?
Yes - you can hear some tests here.


What audio inputs does the Blackmagic Ursa Mini have?
The Ursa Mini has 2 x XLR analog switchable between mic and line levels with Phantom power support.


What audio outputs does the Blackmagic Ursa have?
The Ursa has a 1/4” jack output for headphone monitoring.

There is also embedded stereo audio on the 12G-SDI output. The 12G-SDI signal is 48kHz 24bit.


How do I monitor levels on the Blackmagic Ursa Mini?
You can monitor levels on the touch screen.


Does the Blackmagic Ursa Mini come with a microphone?
Yes, the Ursa comes with an Integrated Stereo microphone that can be used as a VERY ROUGH guide track. The quality of this microphone is fairly low due to the fact it's internal to the camera.


Does the Blackmagic Ursa Mini have an Internal Speaker?
Yes, the Ursa Mini has an Integrated mono speaker which can be used for audio playback on the camera.


What format is the audio recorded to on the Blackmagic Ursa?
When recording to ProRes or DNxHD, Uncompressed 48kHz 24bit audio is embedded into the ProRes or DNxHD files. When recording to Compressed RAW CinemaDNG, Uncompressed 48kHz 24bit audio is included in a standalone WAV file.


Does the Blackmagic Ursa Mini provide Phantom Power?
Yes, Phantom Power can be activated via the touch screen individually for both XLR inputs.


Does the Blackmagic Ursa Mini support external timecode?
Yes, the camera features a BNC Timecode/Reference Input.


Can I adjust the audio levels on the camera while recording?
Yes - it has physical knobs, but you can also adjust the gain via the touch screen.


How is the quality of the headphone output on the camera?
Much better than previous cameras - it's much less noisy. However, it's also very delayed from the picture, so it's very hard to monitor while you're shooting. It's great for calibration and confidence checking, and also playback.


--------------------------


BLACKMAGIC URSA:


Can I record decent audio on the Blackmagic Ursa?
Yes - the Ursa records high quality audio.


What audio inputs does the Blackmagic Ursa have?
The Ursa has 2 x XLR analog switchable between mic and line levels with Phantom power support.


What audio outputs does the Blackmagic Ursa have?
The Ursa has a 1/4” jack output for headphone monitoring.

There is also embedded stereo audio on the 12G-SDI output. The 12G-SDI signal is 48kHz 24bit.


How do I monitor levels on the Blackmagic Ursa?
There is a massive audio meter on the right side of the camera. You can also monitor the audio via the touch screen.


Does the Blackmagic Ursa come with a microphone?
Yes, the Ursa comes with an Integrated mono microphone that can be used as a VERY ROUGH guide track. The quality of this microphone is fairly low due to the fact it's internal to the camera.


Does the Blackmagic Ursa have an Internal Speaker?
Yes, the Ursa has an Integrated mono speaker which can be used for audio playback on the camera.


What format is the audio recorded to on the Blackmagic Ursa?
When recording to ProRes or DNxHD, Uncompressed 48kHz 24bit audio is embedded into the ProRes or DNxHD files. When recording to Compressed RAW CinemaDNG, Uncompressed 48kHz 24bit audio is included in a standalone WAV file.


Does the Blackmagic Ursa provide Phantom Power?
Yes, Phantom Power support was enabled in the 1.9.9 firmware release.


Does the Blackmagic Ursa support external timecode?
Yes, the camera features a BNC timecode in and timeout out as well as a Reference Input.


Can I adjust the audio levels on the camera while recording?
Yes.


How is the quality of the headphone output on the camera?
We have not personally tested the Ursa. If you have, let us know!


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BLACKMAGIC STUDIO CAMERA:


Can I record decent audio on the Blackmagic Studio Camera?
We haven't tested the Blackmagic Studio Camera. If you have, let us know!


What audio inputs does the Blackmagic Studio Camera have?
The Studio Camera has 2 x XLR analog switchable between mic and line levels with Phantom power support.


What audio outputs does the Blackmagic Studio Camera have?
The Studio Camera a Aviation headphone (Fixed Wing Plugs) output for talkback and audio monitoring.

There is also embedded stereo audio on the 3G-SDI output. The 3G-SDI signal is 48kHz 24bit.


How do I monitor levels on the Blackmagic Studio Camera?
We believe there will be on-board audio meters in a future software update.


Does the Blackmagic Studio Camera come with a microphone?
Yes, the Studio Camera comes with an Integrated mono microphone that can be used as a VERY ROUGH guide track. The quality of this microphone is fairly low due to the fact it's internal to the camera.


Does the Blackmagic Studio Camera have an Internal Speaker?
Yes, the Studio Camera has an Integrated mono speaker which can be used for audio playback on the camera.


Does the Blackmagic Studio Camera provide Phantom Power?
Yes. Some users have reported problems with it, however this has been addressed in the 1.8 firmware release.


Can I adjust the audio levels on the camera while recording?
Yes.

Does the Blackmagic Studio Camera have overload protection?
No.


How is the quality of the headphone output on the camera?
We won't know for certain until we get more feedback from users.


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BLACKMAGIC POCKET CINEMA CAMERA:


What audio inputs does the Blackmagic Pocket Cinema Camera have?
The BMPCC has 1 x 3.5mm stereo audio plug. Unlike the BMCC this input is UNBALANCED.


What audio outputs does the Blackmagic Pocket Cinema Camera have?
The BMPCC has a 1 x 3.5mm stereo headphone output for monitoring. There is also embedded audio on the HDMI output, meaning you could monitor the audio using a third-party product.


How do I monitor levels on the Blackmagic Pocket Cinema Camera?
From firmware release version 1.9.3, you now have audio meters on camera. You can also monitor levels via the embedded audio coming off the HDMI port. The HDMI signal contains Stereo 48kHz 24bit audio.


What are some examples of third-party video monitors or viewfinders that allow you to monitor audio from an embedded HDMI signal?
You could try the Cineroid EVF4RVW, TVLogic VFM-056WP, Ikan MD7, Kinotehnik LCDVFe or Alphatron EVF-035W-3G. You can also use SDI only monitors with a HDMI to SDI adapter.


Does the Blackmagic Pocket Cinema Camera come with a microphone?
Yes, the BMPCC comes with an Integrated Stereo microphone that can be used as a VERY ROUGH guide track. The quality of this microphone is fairly low due to the fact it's internal to the camera.


Does the Blackmagic Pocket Cinema Camera have an Internal Speaker?
Yes, the BMPCC has an Integrated mono speaker which can be used for audio playback on the camera.


What format is the audio recorded to on the Blackmagic Pocket Cinema Camera?
When recording to ProRes or DNxHD, Uncompressed 48kHz 24bit audio is embedded into the ProRes or DNxHD files.


Does the Blackmagic Pocket Cinema Camera provide Plug-in Microphone Power?
Yes, the Blackmagic Pocket Cinema Camera supplies plug-in power of 2.5V on the Microphone Port when Channel 1 and 2 are set to "Mic" in the menu. This has been tested with the Tascam TM-2X by a community member.


What are some examples of a small shotgun microphone that works with the Blackmagic Pocket Cinema Camera?
It's worth having a look at the Q DSLR-Video Microphone Kit (AUD$110). It's battery powered, so it doesn't require additional plug-in or phantom power. The Sony ECM-CG50 (AUD$$220.00) and Sennheiser MKE 400 (AUD$189.00) are two other battery powered options.


Does the Blackmagic Pocket Cinema Camera support external timecode?
The only way to record timecode to the BMPCC is to connect your timecode generator signal to one of the two audio inputs on the camera. You can then use DaVinci Resolve (9.0.3 and above), Avid Media Composer or Adobe Premiere CC to translate the audio timecode data into an additional timecode track, which can be used for syncing purposes. Final Cut Pro users can use 3rd party plugins such as AuxTC reader.


Can I adjust the audio levels on the camera while recording?
Yes, you can - however there will be a noticeable clicking in the recorded audio, and is therefore not recommended.


How is the quality of the headphone output on the camera?
Fairly poor. Our recommendation would be to listen to the audio feed on the HDMI signal.


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BLACKMAGIC PRODUCTION 4K:

Can I record decent audio on the Blackmagic Production Camera 4K
We've been able to get "decent" audio from the BMP4K on the 1.6.1 firmware using an external pre-amp. The frequency response issue doesn't exist on this camera (like it does on the BMCC on firmware previous to 1.8). We recommend using the latest 1.9.9 firmware, which addresses majority of the major audio concerns (including on-camera meters).

An external pre-amp/mixer is a given if you want to get good audio, regardless of what camera you're using. I wouldn't connect a ME66 directly to an Alexa ever if I was being serious with the audio - so you shouldn't expect you can just connect a ME66 directly to a BMC. Having said that - it WORKS - and you could connect a microphone directly to the camera as a guide track.

If you're doing anything that requires CRITICAL audio - then I'd still strongly suggest using an external audio recorder, and just use the BMP4K audio as a guide track and timecode reference. Even then, I'd still recommend a good external pre-amp/mixer.


What audio inputs does the Blackmagic Production Camera 4K have?
The BMP4K has 2 x 1/4” BALANCED jacks for professional analog audio, switchable between mic and line levels.

The BALANCED part is extremely important, because if you use incorrect cabling with the camera, due to the way balanced audio works (see above), the signal might cancel itself out. Balanced audio works on the principle that two identical signals which are opposite polarities (often erroneously called "out of phase") will cancel each other out. The cables used in such systems are designed to carry two versions of the signal and manipulate the polarities of these signals to eliminate noise.


What audio outputs does the Blackmagic Production Camera 4K have?
The BMP4K has a 1 x 3.5mm stereo headphone output for monitoring. There is also embedded audio on the HD-SDI output, meaning you could use a product such as the Blackmagic Audio Monitor to monitor levels coming off the HD-SDI signal. The HD-SDI signal is 48kHz 24bit.


How do I monitor levels on the Blackmagic Production Camera 4K?
From firmware release 1.9, you can now via audio levels on camera. You can also connect a Thunderbolt computer to the BMP4K, and monitor audio levels using UltraScopes, which is a software package included with the camera. Alternatively, you could also connect a product such as the SmartScope Duo 4K (or 3rd party products) and monitor the audio levels coming off the HD-SDI signal. The HD-SDI signal is 48kHz 24bit.


What are some examples of third-party video monitors or viewfinders that allow you to monitor audio from an embedded SDI signal?
You could try the Cineroid EVF4CSS, TVLogic VFM-056WP, Ikan MD7 or Alphatron EVF-035W-3G. You can also use HDMI only monitors with a SDI to HDMI adapter.


Does the Blackmagic Production Camera 4K come with a microphone?
Yes, the BMP4K comes with an Integrated mono microphone that can be used as a VERY ROUGH guide track. The quality of this microphone is fairly low due to the fact it's internal to the camera.


Does the Blackmagic Production Camera 4K have an Internal Speaker?
Yes, the BMP4K has an Integrated mono speaker which can be used for audio playback on the camera.


What format is the audio recorded to on the Blackmagic Production Camera 4K?
When recording to ProRes or DNxHD, Uncompressed 48kHz 24bit audio is embedded into the ProRes or DNxHD files. Eventually when RAW is released in a future firmware update, it will record Uncompressed 48kHz 24bit audio included in a standalone WAV file.


Does the Blackmagic Production Camera 4K provide Phantom Power?
No, it does not.


Does the Blackmagic Production Camera 4K support external timecode?
The only way to record timecode to the BMP4K is to connect your timecode generator signal to one of the two audio inputs on the camera. You can then use DaVinci Resolve (9.0.3 and above), Avid Media Composer or Adobe Premiere CC to translate the audio timecode data into an additional timecode track, which can be used for syncing purposes. Final Cut Pro users can use 3rd party plugins such as AuxTC reader.


Can I adjust the audio levels on the camera while recording?
Yes, you can - however there will be a noticeable clicking in the recorded audio, and is therefore not recommended.


How is the quality of the headphone output on the camera?

Fairly poor. Our recommendation would be to listen to the audio feed on the HD-SDI signal.


--------------------------


BLACKMAGIC CINEMA CAMERA EF & MFT:

Can I record decent audio on the Blackmagic Cinema Camera EF/MFT?
We've been able to get "usable" audio from the BMCC on both the 1.2.1 and 1.3 firmware using an external pre-amp. Unfortunately though with both firmware releases you need to do some post-processing to make it sound "right". The 1.8 firmware however fixes the DC offset and frequency attenuation issues. We recommend using the latest 1.9.9 firmware, which addresses majority of the major audio concerns (including on-camera meters).

An external pre-amp/mixer is a given if you want to get good audio, regardless of what camera you're using. I wouldn't connect a ME66 directly to an Alexa ever if I was being serious with the audio - so you shouldn't expect you can just connect a ME66 directly to a BMC.

If you're doing anything that requires CRITICAL audio - then I'd still strongly suggest using an external audio recorder, and just use the BMC audio as a guide track and timecode reference. Even then, you still need a good external pre-amp/mixer.


What audio inputs does the Blackmagic Cinema Camera EF/MFT have?
The BMCC has 2 x 1/4” BALANCED jacks for professional analog audio, switchable between mic and line levels.

The BALANCED part is extremely important, because if you use incorrect cabling with the camera, due to the way balanced audio works (see above), the signal might cancel itself out. Balanced audio works on the principle that two identical signals which are opposite polarities (often erroneously called "out of phase") will cancel each other out. The cables used in such systems are designed to carry two versions of the signal and manipulate the polarities of these signals to eliminate noise.


What audio outputs does the Blackmagic Cinema Camera EF/MFT have?
The BMCC has a 1 x 3.5mm stereo headphone output for monitoring. There is also embedded audio on the HD-SDI output, meaning you could use a product such as the Blackmagic Audio Monitor to monitor levels coming off the HD-SDI signal. The HD-SDI signal is 48kHz 24bit.


How do I monitor levels on the Blackmagic Cinema Camera EF/MFT?
From the 1.9.3 firmware release, you can now monitor audio levels on-camera. You can also connect a Thunderbolt computer to the BMCC, and monitor audio levels using UltraScopes, which is a software package included with the camera. Alternatively, you could also connect a product such as the SmartScope Duo 4K (or 3rd party products) and monitor the audio levels coming off the HD-SDI signal. The HD-SDI signal is 48kHz 24bit.


What are some examples of third-party video monitors or viewfinders that allow you to monitor audio from an embedded SDI signal?
You could try the Cineroid EVF4CSS, TVLogic VFM-056WP, Ikan MD7 or Alphatron EVF-035W-3G. You can also use HDMI only monitors with a SDI to HDMI adapter.


Does the Blackmagic Cinema Camera EF/MFT come with a microphone?
Yes, the BMCC comes with an Integrated mono microphone that can be used as a VERY ROUGH guide track. The quality of this microphone is fairly low due to the fact it's internal to the camera.


Does the Blackmagic Cinema Camera EF/MFT have an Internal Speaker?
Yes, the BMCC has an Integrated mono speaker which can be used for audio playback on the camera.


What format is the audio recorded to on the Blackmagic Cinema Camera EF/MFT?
When recording to ProRes or DNxHD, Uncompressed 48kHz 24bit audio is embedded into the ProRes or DNxHD files. When recording to RAW 2.5K CinemaDNG, Uncompressed 48kHz 24bit audio is included in a standalone WAV file.


Does the Blackmagic Cinema Camera EF/MFT provide Phantom Power?
No, it does not.


Does the Blackmagic Cinema Camera EF/MFT support external timecode?
The only way to record timecode to the BMCC is to connect your timecode generator signal to one of the two audio inputs on the camera. You can then use DaVinci Resolve (9.0.3 and above), Avid Media Composer or Adobe Premiere CC to translate the audio timecode data into an additional timecode track, which can be used for syncing purposes. Final Cut Pro users can use 3rd party plugins such as AuxTC reader.


Can I adjust the audio levels on the camera while recording?
Yes, you can - however there will be a noticeable clicking in the recorded audio, and is therefore not recommended.


How is the quality of the headphone output on the camera?
Fairly poor. Our recommendation would be to listen to the audio feed on the HD-SDI signal.


Can I use the MixPre-D with the BMCC?
Yes - refer to this thread.


--------------------------


GENERAL INFORMATION:


What is a DC offset?
DC offset is an offsetting of a signal from zero. If you look on an audio waveform it would mean that the waveform in default view appears not to be centered on the 0.0 horizontal line. A sound that has DC offset will not be at its loudest possible volume when amplified or normalized. This is because the offset reduces the headroom between the peak level of the audio and the maximum possible level without clipping. This problem can possibly extend to the mix as a whole, since a sound with DC offset and a sound without DC offset will have DC offset when mixed.


What is Line Level?
Line level is the specified strength of an audio signal used to transmit analog sound between audio components such as CD and DVD players, TVs, audio amplifiers, and mixing consoles. As opposed to line level, there are weaker audio signals, such as those from microphones and instrument pickups, and stronger signals, such as those used to drive headphones and loudspeakers. The strength of these various signals depends on the output voltage of the source device, along with its output impedance.

A line level describes a line's nominal signal level as a ratio, expressed in decibels, against a standard reference voltage. The nominal level and the reference voltage against which it is expressed depend on the line level being used. While the nominal levels themselves vary, only two reference voltages are common: decibel volts (dBV) for consumer applications, and decibels unloaded (dBu) for professional applications.

The most common nominal level for consumer audio equipment is −10 dBV, and the most common nominal level for professional equipment is +4 dBu (by convention, decibel values are written with an explicit sign symbol).

The Blackmagic Cinema Camera's expect professional +4 dBu signals. If you're trying to get a -10 dBV signal into the camera, one easy way would to just leave the camera as Mic Level and use an in-line XLR pad to reduce the signal. Not ideal, as the pre-amp on the BMC is not great, but it would be a cheap and quick fix. Alternatively, you could use a pre-amp on the camera to boost the signal by 11.79dB.

Essentially if you plug a -10dBV output into a +4dBu input the signal is coming in 11.79dB quieter than the gear was designed for... so you need to turn something up. However, in all cases connecting a -10dBv output to the input of +4dBU gear will increase the noise floor.


What does Balanced Audio mean?
Balanced audio is a method of interconnecting audio equipment using balanced lines. This type of connection is very important in sound recording and production because it allows for the use of long cables while reducing susceptibility to external noise.

Balanced audio cables use an extra line, and consist of a hot line (positive), cold line (negative) and earth. The audio signal is transmitted on both the hot and cold lines, but the voltage in the cold line is inverted (i.e. the polarity is changed) so it is negative when the hot signal is positive. These two signals are often referred to as being 180 degrees out of phase with each other but this is technically incorrect — the signals are not actually out of phase, they are opposite polarities, i.e. one signal is effectively flipped upside down rather than being delayed 180°. This confusion could be due to the fact that in a graphical representation of a sine wave (pictured below) the effect of changing polarity and changing the phase 180° looks the same. When the cable is plugged into an input (on a mixer or other equipment) the hot and cold signals are combined. Normally you would expect these two signals to cancel each other out, but at the input stage the inversion is reversed before being merged together, so they actually combine to form a stronger signal.

Along the length of the cable, noise can be introduced from external sources such as power cables, RF interference, etc. This noise will be identical on both hot and cold lines. This is known as a common mode signal - a signal which appears equally on both conductors of a two wire line. So the hot and cold lines carry two signals: A desirable audio signal which has an opposite voltage on each line, and unwanted noise which is the same on both lines. This is where the trick of balanced audio kicks in. At the input stage when the inverted audio signal is re-inverted to make both desirable audio signals the same, the unwanted noise is inverted. Voila - all the unwanted noise is cancelled out, leaving only the combined original signal.


What is Phantom Power?
Phantom power is a means of distributing a DC current through audio cables to provide power for microphones and other equipment. The supplied voltage is usually between 12 and 48 Volts, with 48V being the most common. Individual microphones draw as much current from this voltage as they need.

A balanced audio signal connected to a 3 pin XLR has the audio signal traveling on the two wires – usually connected to pin 2 (+ve) and pin 3 (-ve). Pin 1 is connected to the shield, which is earthed. The audio signal is an AC (alternating current), whereas phantom power is DC (direct current).

The DC phantom power is transmitted simultaneously on both pin 2 and 3, with the shield (pin 1) being the ground. Since the DC voltage on the ‘hot’ and ‘cold’ pins (2 & 3) is identical, it is seen by equipment as “common mode” noise and rejected, or ignored, by the equipment. If you put a volt meter on pins 1 & 2, or pins 1 & 3, you will see the 48v DC phantom power, but if you meter pins 2 & 3 (the audio carrying wires) you will see no voltage. The DC voltage can be harnessed however, and used to power microphones or other devices. In summary, audio signals transmit as AC current, whereas powered equipment requires DC current to operate. Phantom power is a clever way of using one cable to transmit both currents.


What is UltraScope?
Blackmagic UltraScope provides technically accurate waveform monitoring with a beautifully designed computer interface. Connect Blackmagic Cinema Camera to any compatible computer using Thunderbolt technology to display 6 live scope views on a single monitor. Use UltraScope on set or in any location for Parade, Waveform, Vectorscope and Histogram signal measurement. UltraScope includes picture view, audio level and phase monitoring. It is bundled for free with the camera.


Why does the juicedLink low-noise preamps use Mic Level instead of Line Level outputs?
Robert from juicedLink says:
From the principle of the the noise figure of cascaded amplifiers, a properly designed a low noise preamplifier will set the noise figure of the entire system. In this case, from a signal to noise perspective, there's no benefit for going in to a recorder LINE level. The recorder at LINE is just going to engage an input attenuator, and then subsequently go through the same signal chain as the MIC input.

The where there is a benefit for running line level, has nothing to do with signal to noise in the recording device. If there's any electromagnetic interference they can be picked up on a long cable run, it's relative affect will be smaller on a line level signal than a MIC level signal. But, for the purposes of a camera preamplifier like a juicedLink, the exposure that you have to electromagnetic susceptibility is quite small, since your cable run is only about 6 inches.

Regarding the camera results at LINE level, my little videos were more focused on an applications guide for users of a juicedLink, so I didn't really cover that. But if I recall correctly, the LINE sensitivity in 1.2 was off the scale (required 100% gain in the camera for a reference test tone from and ENG mixer like the MixPre). So, the SNR in MIC was actually better than in LINE (from what I tested). The sensitivity of 1.3 in LINE was within range, but I don't recall the cal gain level in the camera.



What cable should I use to get from a H4N to the BMCC?
Discussed here.


--------------------------


FIRMWARE NOTES:


What firmware release would you currently recommend using for best audio performance?
We'd always recommend using the latest firmware release. The 1.8 firmware release addressed the frequency response issue of previous firmware builds. The 1.9+ firmware releases added audio meters to all of the camera line. The 4.0 release for the Ursa Mini brings with it a whole heap of audio functionality improvements.


Information on the 1.1, 1.2 and 1.2.1 camera firmware release:
- This firmware release has slightly better frequency response when set to Line Level as opposed to Mic Level. In both cases however some lower frequency attenuation occurs. Luckily it seems the filtering is done after the analog-to-digital conversion and can easily be reconstructed without penalty in post production.
- This firmware release contains a DC Offset bug which must be fixed in post production.
- The DC Offset sadly penalises the best possible signal to noise ratio performance.
- The DC Offset varies depending on the levels set in the camera.
- MediaExpress version 3.1.2 incorrectly displays audio levels (about 5dB too high).
- When using Mic Level inputs - the "sweet spot" is between 20-30% gain level in the camera.
- If you're using a Mic-level preamp, such as a juicedLink low-noise pre-amp we'd recommend setting the camera to Mic Level 25%, and then adjust the pre-amp to -12dB.
- If you're using a mixer such as the Sound Devices 302, we'd recommend setting the camera to Mic Level 25%, and then apply -40dB XLR Attenuation using the 302 menu.
- If you're using a mixer such as the Sound Devices 552, we'd recommend setting the camera to Line Level 77%, and then outputting Line Level from the 552.
- The camera automatically switches from Mic Level to Line Level when "hot" signal is received. The camera must be restarted to reset this.
- The camera automatically shuts off the Audio Functionality when a "very hot" signal is received when in Line Level. The camera must be restarted to reset this.


Information on the 1.3, 1.3.1, 1.4, 1.4.1, 1.5 and 1.5.1 camera firmware release:
- This firmware release no longer contains the DC Offset Bug.
- MediaExpress, UltraScope and the camera itself now have uniform meter correlation.
- The camera no longer switches from Mic Level to Line Level when overloaded.
- The camera no longer switches off audio functionality when a Line Level Signal is overloaded.
- This firmware release sadly introduces a frequency response issue, where low frequency sounds are heavily attenuated in both Mic and Line Level (although Mic Level is far worse). Luckily it seems the filtering is done after the analog-to-digital conversion and can easily be reconstructed without penalty in post production.
- When using Mic Level inputs - the "sweet spot" is around 80% gain level in the camera, as digital attenuation occurs in the camera up until the 80% mark.
- When using Line Level inputs - the "sweet spot" seems to be 100% gain level in the camera.


Information on the 1.6.1 camera firmware release:
- This release doesn't seem to offer any audio benefits for BMCC and Pocket Camera users - however, as it offers "General stability improvements", we still recommend upgrading. This firmware release was primarily designed for the BMP4K - in which it address the frequency response issue - however it seems to introduce a storage delay/reverb effect on the headphone output of the BMP4K. We're still unsure whether this is a firmware or hardware glitch.

You can read more about testing out the 1.6.1 release here.


Information on the 1.8 camera firmware release:
- This release fixes the frequency response issue on the BMCC.


Information on the 1.9.3 camera firmware release:
- David Green has done some detailed tests which can be found here.


How do I fix the frequency response issue on a Mic Level input when using the 1.3/1.4/1.5 firmware?
Apply a 500Hz 15dB 24dB/oct and a 250Hz 15dB 24dB/oct Low Shelf to the audio. Please refer to
for further information.

You can also use this example of an effect you could apply in Adobe Audition.

Thomas Bruegger has also kindly created an audio preset for Premiere.


How do I fix the frequency response issue on a Line Level input when using the 1.3/1.4/1.5 firmware?
Here's an example of an effect in Adobe Audition you can try.

Thomas Bruegger has also kindly created an audio preset for Premiere.


Can I plug a microphone directly into the camera when using the 1.3 firmware?
Yes, you can. You can listen to some examples here. Keep in mind that the camera does NOT supply Phantom Power, and is expecting a BALANCED audio signal.


How does Mic Level compare to Line Level on the 1.3 firmware?
You can listen to some examples here.


How does the frequency response compare between Mic Level & Line Level on the 1.3 firmware?
You can listen to some examples here.


Do all balanced cables and adapters work with the Blackmagic Cinema Camera?
No.
Last edited by Chris Hocking on Thu Aug 18, 2016 7:08 am, edited 24 times in total.
Offline

Miriana Marusic

  • Posts: 8
  • Joined: Sat Mar 30, 2013 5:41 am

Re: Frequently Asked Audio Questions

PostSun Nov 10, 2013 1:40 am

This is fantastic to have all the info together.
Thank you very much.
Offline

Steve Wake

  • Posts: 105
  • Joined: Thu Apr 18, 2013 11:55 pm

Re: Frequently Asked Audio Questions

PostSun Nov 10, 2013 5:04 am

Great summary. Thanks!
Definitely should be a sticky.

One more for the Monitor/EVF list for audio meters. HDMI only, so only for Pocket. Kinotehnik LCDVFe: http://www.kinotehnik.com/products/elec ... r/overview
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Paul Kapp

  • Posts: 605
  • Joined: Tue Sep 03, 2013 7:43 am
  • Warnings: 1

Re: Frequently Asked Audio Questions

PostSun Nov 10, 2013 8:14 am

Awesome.
Thanks Chris.
Mods. Sticky?

I can confirm the Cineroid EVF4RVW & TVLogic VFM-056WP both have audio monitoring of Pocket via HDMI.
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Frank Glencairn

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Re: Frequently Asked Audio Questions

PostSun Nov 10, 2013 9:02 am

Great writeup Chris.
http://frankglencairn.wordpress.com/

Set your zebras to 100%, ETTR and you're golden - and NO, you can't use TB as output for an external monitor, and you can't download the footy via TB ether.
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Re: Frequently Asked Audio Questions

PostSun Nov 10, 2013 9:47 am

Will this new Tascam mic work on the BMPC?

It requires plug in power from the camera to work.
http://www.bhphotovideo.com/c/product/1 ... enser.html
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Chris Hocking

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Re: Frequently Asked Audio Questions

PostSun Nov 10, 2013 11:41 pm

Steve Wake wrote:One more for the Monitor/EVF list for audio meters. HDMI only, so only for Pocket. Kinotehnik LCDVFe:


Added.

Dan Harris wrote:Will this new Tascam mic work on the BMPC?


I haven't tested that exact microphone, but I have tested other plugin powered microphones and they didn't work, so I'm ASSUMING that this microphone will not work either. Someone please correctly me if I'm wrong and I will update the original post.
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dharmaone

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Re: Frequently Asked Audio Questions

PostMon Dec 09, 2013 10:13 am

so for BMPCC, basically any electret mic which is powered by 2 x 1.5v AAA or 9v should work?
http://londonhelicam.co.uk
http://twitter.com/dharmaone
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Chris Hocking

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Re: Frequently Asked Audio Questions

PostFri Dec 20, 2013 8:44 am

Audio Measurements for the Blackmagic Cinema Camera:
http://www.beachtek.com/news/audio-meas ... ma-camera/
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Thomas Schumacher

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Re: Frequently Asked Audio Questions

PostFri Dec 20, 2013 10:00 am

Great, thanks. BM should pay you, Chris.



And Frank and Adam and ...
My award-winning doc: https://vimeo.com/91622063
ARE YOU HAPPY? https://vimeo.com/72724154
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Re: Frequently Asked Questions - Audio

PostSun Feb 16, 2014 11:41 am

The Zacuto EVF also can display audio levels.
Cheers,
Alex
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JL Rocheron

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Re: Frequently Asked Questions - Audio

PostSun Feb 16, 2014 9:30 pm

Since the update my Blackmagic pocket makes a strange sound in background. http://audiour.com/playlist/j1frjicg I redid the update and even switch to 1.51 nothing changes ... Have you an idea of the problem? ( Sorry for my english )

ps : This "song" , only when press record in camera
JL Rocheron
Film Director - Stunt Coordinator
www.onde2choc.com
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Larry Price

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Re: Frequently Asked Questions - Audio

PostTue Feb 18, 2014 10:31 am

Hi Chris;
KUDOS: Great stuff. Reading your posts is like taking a course in sound engineering. Much of it over my head. But perhaps my problems and your solutions may be enlightening for others. I've loaded up with equipment to get the job done. And hope that the information you provide will not only help me but others. Much of what I bought I did after finding recommendations on the BM Cinematography forum.

BACKGROUND: So you don't think I'm just a crank, or a newbie, I've been in documentary production for decades, and I can't recall being this stumped, but of course I was never really a sound guy even though my first job was as a soundman running the mixer for a single system news Aurikon film camera, then I graduated to the Niagra III, was awed by the Nagra IV. Then came video. And it keeps coming. I left sound to become a director, then producer, then one-man band traveling around the world shooting with the Sony VX1000, Canon G1, Sony DSR 300, Canon HV20 (loved that camera), and now the BMPCC. Of course on the set of documentaries as director or producer I frequently had big HD cameras, and all that. But for myself, I bought the BMPCC. And I'm a little worried about the choice for one-man-band filmmaking, even though the pictures are great.

COMPLAINT: Like everyone else, I'm disappointed with BM for not attending to the professional side of this sound issue.

Now I hope to be able to pick your brains. Please excuse my rude behavior. Frankly, I'm worried about the audio problems. Usually I just slap the Beachetek on the camera, hook up the Sennheiser, and the Rode, put the headphones on, turn on the light, and do my interviews. The BMPCC seems to require a different approach. And a steep learning curve.

HERE ARE MY QUESTIONS I HOPE YOU CAN ANSWER.
A.) Do you have basic audio settings for use on this camera with an external battery powered mic?
I've read through the posts in this thread and while much of it flies over my head, a few things caught my eye and confused me. For instance, should I be using Line or Mic? 100 per cent or 50 per cent for interviews?
B.) I'm trying to hook up some legacy hardware. Which should work, and which not?
Should I be using a pre-amp (see below) and battery powered mic hooked into the BMPCC input? again, line or mic? Again, what percent? I have a BMPCC and
1.) Beachtek pre DSLR DXA-2s that I've been using for years. Usually I hook it up to my old Rode Video mic (not pro. My Sennheiser M66 was stolen, alas.) I can't set the Rode to +20 so no idea what's going in. I crank up the Beachtek to full power. Both knobs to the right. Mic set to 100 per cent. Headphones to 100 per cent.
2.) I also have a Tascam DR 100 mark II. Bought it for the move to DSLR from HDV but jumped on the BMPCC bandwagon instead. Haven't used "double-system" recording in thirty-odd years since I left the film world.
3.) Is it advisable to hook up the Tascam direcly to the input of BMPCC, or run it as a second recording unit?
4.) Usually for interviews I use my old Shure wireless lavalier (vp3cv), with the receiver hooked into the XLR of the Beachtek. Usually I have no problems. Rode on the camera, lav on the subject. Headphones on the cameraman. Now I get little or nothing from the head phones.
5.) I also have a Tascam US 144 mkII that I use for recording narration into my MBP using SoundTrackPro.
6.) I bought a Liliput 664/O/P IPS peaking HDMI in out field monitor because it had audio monitoring just so I could see the volume levels.

What combination of these devices would you recommend, at what settings, and what should be replaced?

(ALSO: I bought the Kintechnik LCD loupe because when out in the field I find the BMPCC LCD screen to be much more "point and hope" than "point and shoot." This is Just another small annoyance with the BMPCC. Also bought the Centrino cage John Brawley recommended. Need it to hook up all the gear, cutting lengths of screw down to size, fitting with bolts, securing all to the cage. Old expression: never accept a gift you have to feed. I find that the BMPCC needs a lot of sustenance to get the job done.
Having said that.)

SUMMARY: I like the camera.
Have high hopes.

Thanks for any help you can provide,
LP
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Chris Hocking

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Re: Frequently Asked Questions - Audio

PostTue Feb 18, 2014 9:30 pm

pricecom wrote:A.) Do you have basic audio settings for use on this camera with an external battery powered mic? I've read through the posts in this thread and while much of it flies over my head, a few things caught my eye and confused me. For instance, should I be using Line or Mic? 100 per cent or 50 per cent for interviews


Whether you use Mic or Line really depends on what you're connecting to the camera.

For example, some devices like the BMC388 low-noise preamp have a amplified mic level output, so you would set the Pocket to Mic. I personally normally use a Sound Devices mixer (such as the 302 or 552), and set both the mixer and the camera to Line. If you're connecting a microphone (such as a ME66 or NT3) directly to the camera, then you could select Mic Level. If you're connecting a wireless receiver to the camera, then I'd set both the receiver and camera to Line Level. Some wireless receivers (like your VP3) only offer Mic Level outputs, so in that case, you'd set the camera to Mic Level. Again, it just all depends on what exactly you're hooking up.

As for the level percentage - it depends on what you have connected, and how "loud" the input is. If you're connecting a microphone directly to the camera, then the volume you set will depend on how loud your talent is and the environment you're shooting in.

pricecom wrote:B.) I'm trying to hook up some legacy hardware. Which should work, and which not?
Should I be using a pre-amp (see below) and battery powered mic hooked into the BMPCC input? again, line or mic? Again, what percent? I have a BMPCC and
1.) Beachtek pre DSLR DXA-2s that I've been using for years. Usually I hook it up to my old Rode Video mic (not pro. My Sennheiser M66 was stolen, alas.) I can't set the Rode to +20 so no idea what's going in. I crank up the Beachtek to full power. Both knobs to the right. Mic set to 100 per cent. Headphones to 100 per cent.


The DXA-2 is a great little unit - but it was really designed to work with old handy-cam.

It's not a pre-amp, but more a simple adapter to get a single balanced XLR connection and a single unbalanced mini-jack connection into the Mic Level Mini-Jack connection of a consumer handy-cam. The only benefit of using a Rode Video Mic connected to a DXA-2 connected to a BMPCC is that you're putting a 10 step attenuator in line, allowing you to easily adjust the volume of the input. However, apart from this volume dial - there's no real benefit of using the DXA-2, as opposed to connecting the Rode directly to the camera.

There are a few different versions and generations of the Rode VideoMic. Only the Rode VideoMic Pro has the +20dB level boost that is designed for use with DSLR/prosumer cameras, allowing you to reduce the camera's preamp level (or mic-input level), effectively reducing the amount of noise generated by the camera's comparatively low quality audio circuitry. The standard Rode VideoMic has a -20dB level attenuation (i.e. PAD) - which will actually REDUCE the level, not increase it.

Looking through these forums, a lot of people have reported success with the VideoMic Pro (with the +20dB boost applied), and lots of people have reported issues with the standard VideoMic (which lacks the boost functionality).

It's been a while since I did any tests with the Pocket, and our camera is currently overseas on a job - but with the current firmware, depending on what version/generator of the VideoMic you have, you might not be able to get enough level with it connected directly to the camera - in which case you need a pre-amp, such as the BMC388 Blackmagic Cinema Camera Preamp.

pricecom wrote:2.) I also have a Tascam DR 100 mark II. Bought it for the move to DSLR from HDV but jumped on the BMPCC bandwagon instead. Haven't used "double-system" recording in thirty-odd years since I left the film world.


The DR-100 will give you better audio results than the Pocket - if your workflow allows this - I would just record audio to the DR-100, and a guide track to the Pocket so that you can use Plural Eyes or similar to sync in post.

If however, for what-ever reason, a double-system is not possible, then using a preamp with the Pocket will get you better results than without.

pricecom wrote:3.) Is it advisable to hook up the Tascam direcly to the input of BMPCC, or run it as a second recording unit?


I'd do both. I'd record on the DR-100 as your "master recording" that you'll use in the edit, but I'd record a guide track to the Pocket for easy syncing.

pricecom wrote:4.) Usually for interviews I use my old Shure wireless lavalier (vp3cv), with the receiver hooked into the XLR of the Beachtek. Usually I have no problems. Rode on the camera, lav on the subject. Headphones on the cameraman. Now I get little or nothing from the head phones.


Have you tried hooking up the Shure VP3 directly to the camera? It has a Mic Level Output, so set the Pocket to Mic Level. The VP3 has a 3–pin miniature connector balanced output, so you'll need to make sure you you have the correct cabling to go to an unbalanced mini-jack on the Pocket. If you're still not getting enough level, then you'll have to look at going down the pre-amp route.

pricecom wrote:5.) I also have a Tascam US 144 mkII that I use for recording narration into my MBP using SoundTrackPro.


As this is a USB Audio Interface - I don't think it's really useful in this case.

pricecom wrote:6.) I bought a Liliput 664/O/P IPS peaking HDMI in out field monitor because it had audio monitoring just so I could see the volume levels.


Nice one. The lack of on-board meters and the lack of a Thunderbolt port on the Pocket is one of the reasons we basically just gave up on the Pocket for audio recording, and just use a dual recording system.

You can use the meters on your Lilliput to fault find all of the above.

Hope this helps!
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Re: Frequently Asked Questions - Audio

PostTue Feb 18, 2014 10:36 pm

???
JL Rocheron
Film Director - Stunt Coordinator
www.onde2choc.com
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Chris Hocking

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Re: Frequently Asked Questions - Audio

PostTue Feb 18, 2014 10:48 pm

Onde2choc wrote:Since the update my Blackmagic pocket makes a strange sound in background. http://audiour.com/playlist/j1frjicg I redid the update and even switch to 1.51 nothing changes ... Have you an idea of the problem? ( Sorry for my english )

ps : This "song" , only when press record in camera


The on-board microphone on the Pocket has always sounded bad.

See:
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JL Rocheron

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Re: Frequently Asked Questions - Audio

PostTue Feb 18, 2014 11:04 pm

Thank you for the answer, is same internal Noise.
JL Rocheron
Film Director - Stunt Coordinator
www.onde2choc.com
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Larry Price

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Re: Frequently Asked Questions - Audio

PostWed Feb 19, 2014 7:11 am

Hi Chris;
Thanks for the prompt and extensive reply. I appreciate your patience and expertise.
I have a couple more questions.
A.) Should I, could I, use the DXA-20s as the input for the Shure wireless mikes? This gives me
the ability to have balanced sound, and adjust the levels.
B.) Do I understand correctly that input of the mics should go to the Tascam first and then the Beachtek, and beachtek into the Pocket? Or Beachtek to Tascam to Pocket? And that the Tascam will work as a pre-amp for the old Rode putting decent sound level into the Pocket? Or still just as a guide?
C.) If I use the Tascam do I need the Beachtek?
D.) Settings: which settings should I use on the Tascam, stereo or mono recording? I find the Tascam
records very low volume. Need the gain level switch set to high, and wheels cranked up, to get anything decent. That said the old Rode Mic (not pro) records okay through the beachtek, but as I said, needs to be pushed.
E.) Using the combo of Tascam and Beachtek, which settings for recording levels on the Pocket?
F.) I'm told FCPX eliminates the necessity of Pluraleyes.

Really appreciate your help.
Thanks for being so generous with your expertise.
Larry Price
documentary filmmaker
Price Communications, Inc.
Jerusalem
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Chris Hocking

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Re: Frequently Asked Questions - Audio

PostWed Feb 19, 2014 8:13 am

pricecom wrote:A.) Should I, could I, use the DXA-20s as the input for the Shure wireless mikes? This gives me the ability to have balanced sound, and adjust the levels.


Yes you could do this. However, the output of the DXA-20 is Unbalanced and the input on the BMPCC is Unbalanced, so assuming you're mounting the Shure wireless receiver on the camera and connecting it with a short cable to the DXA-20, there's really no advantage. The main benefit of balanced cabling to reduce susceptibility to external noise via long cables.

The ability to adjust the levels easily via the DXA-20 is handy - but depending on your gain structure - you could also just do this on the receiver or the camera.

You'll need to do your own testing to see if it's worth putting the DXA-20 inline.

pricecom wrote:B.) Do I understand correctly that input of the mics should go to the Tascam first and then the Beachtek, and beachtek into the Pocket? Or Beachtek to Tascam to Pocket? And that the Tascam will work as a pre-amp for the old Rode putting decent sound level into the Pocket? Or still just as a guide?


If you're using the DR-100, I'd just forget about the DXA-20. Record your "master" audio to the DR-100 and take a line out of the DR-100 and record it to the Pocket. You'll need to do some tests of your own to determine if you're happy with the quality of the Pocket audio compared to the DR-100.

pricecom wrote:C.) If I use the Tascam do I need the Beachtek?


I'd say not. The DXA-20 is really only useful for DSLR's and consumer handy-cam's.

pricecom wrote:D.) Settings: which settings should I use on the Tascam, stereo or mono recording? I find the Tascam records very low volume. Need the gain level switch set to high, and wheels cranked up, to get anything decent. That said the old Rode Mic (not pro) records okay through the beachtek, but as I said, needs to be pushed.


Not sure what you mean by stereo vs mono recording - basically you just want to record the Rode Video Mic to the Left Channel and the Shure Receiver to the Right Channel of your DR-100. You can then "pan" the audio to left or right in post as required.

As for the levels - you'll have to do your own testing.

pricecom wrote:E.) Using the combo of Tascam and Beachtek, which settings for recording levels on the Pocket?


Using the 1.3 Firmware or greater Mic Level at 100% on the Pocket seems to be the "sweet spot".

pricecom wrote:F.) I'm told FCPX eliminates the necessity of Pluraleyes.


FCPX has pretty good syncing via audio waveforms, and will be sufficient for most jobs - but Pluraleyes is far superior and much more powerful.
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Re: Frequently Asked Questions - Audio

PostFri Feb 21, 2014 11:43 am

Hi Chris;
Again, thanks for taking the time to answer me. Wish I was better at this stuff.
Running into a few problems.

Firstly, surprisingly enough I used the Beachtek DXA 2s with the Rode mic (non-pro), directly into the BMPCC, and it worked okay.
Then I tried through the Tascam, and haven't been able to succeed. The Rode mic I have has the tiny 3/8ths (I think that's the size) mini-plug.
For some reason this doesn't seem to send a signal to the BMPCC from the Tascam. When I hook up the Shure lavalier through XLR plugs on the Tascam that does record on both the Tascam and the BMPCC.

I want to use two channels of recording, Videomic for wild or on-the-spot interviews, and Shure Lavalier for interviews in a confined environment.

I set the bmpcc to input channel 1 and channel two but only get one channel on the Tascam. Don't get separate channels, even when I import to Soundtrak Pro or FCPX to check. I don't know quite what to do about Send channel 1 signal to channel 2 check box. Either way I don't get a signal from the RodeMic (no pro).

I've set the BMPCC to both Line and then Mic to record audio to the same effect with the Rode.

Any idea why the Rode isn't sending out a signal to the Tascam through the Line2 input, non XLR?
Will the Tascam record both XLR from the Shure lavalier and line 3/8 from the Rode simultaneously?

The Shure does go through the tascam to the BMPCC through the XLR. That's it, though. No Rode. Only the camera's built in mic. Again, the Beachtek sends the Rode videomic signal to the BMPCC. Have to double check, but I don't think the Shure will go through if the Rode is hooked up Beachtek to BMPCC without the Tascam. Is it possible the problem is that the BMPCC doesn't receive a two channels through the line.
Or is it simply that I'm too dumb, and that I have to pan the stero signal.

So, how do I get the Tascam to accept the signal of the Rode?
Oh, and when I hook up the Lilliput 664 I see the audio from the Shure but, alas, not the Rode.
And you are quite correct, the quality of the Tascam is excellent, but again, I only get a single channel.
My guess is I'm doing something wrong with the settings either int he Tascam or the BMPCC.

Thanks,
LP
Larry Price
documentary filmmaker
Price Communications, Inc.
Jerusalem
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Chris Hocking

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Re: Frequently Asked Questions - Audio

PostSat Feb 22, 2014 6:11 am

How are you connecting the Rode Video Mic to the DR-100? Are you using an XLR to Mini-jack adapter?

Basically, you want to connect the Rode Video Mic to the left XLR input on the DR-100, and the Shure Wireless Receiver to the right XLR input on the DR-100. To connect the DR-100 to the BMPCC, you would run a mini-jack cable from the Line Out of the DR-100 into the Microphone Input of the BMPCC. If everything is set up correctly, the Rode Video Mic should be recorded to the left channel of the BMPCC and the Shure Wireless will be recorded to the right channel.

The Rode Video Mic has an UNBALANCED output, so you want to try and keep the cable distance as short as possible. This will be find if you're mounting with the DR-100 and Rode Video Mic on top of the camera.
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Larry Price

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Re: Frequently Asked Questions - Audio

PostSat Feb 22, 2014 8:34 pm

Great! Thanks!
As I understand it, all I need to get an adapter Mini to XLR, and I should be fine.
When I hook up the Beachtek, that has a mini socket, with the Shure plugged into the XLR and then run the beachtek into the Tascam's line 2, and then the Tascam into the BMPCC I get sound. I think it is both the Shure and the Rode, but haven't been able to figure out how to separate the channels to check on FCPX. Still a learning curve for me on that. I'll check in my old FCP 6 that I've used for years. But following your advice, the Tascam seems the best way to go. Get a clean recording on the Tascam and at least a guide track on the BMPCC if not a decent recording. I've found, so far, that the BMPCC signal is quiet low from the beachtek and tascam, about 32db. Anyway, thanks for your time and trouble. You have provided me with very useful information. As they said when I was in Sydney and Cairns a couple of months ago, "Good on you mate."
Cheers,
LP
Larry Price
documentary filmmaker
Price Communications, Inc.
Jerusalem
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Alexander Arndt

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Re: Frequently Asked Questions - Audio

PostThu Feb 27, 2014 7:30 pm

Hey Chris,

first of all great of sticking these question all in one place. 2nd you very made it easy for me to get rid of the all in all sound stuff on the bmcc. yeah always good to have some advice things going on you know.

so after all i buyed the mixpre connected it with the cable you posted before and a sennheiser mkh416p48. the settings in the camera is line and channels set around 80. so i recorded some voices and stuff and after all checked the sound file in adobe soundbooth. so i must say that i dont recordnize anything wierd or noisy or bad. to say the sound is really great. so no worries here. the only thing is that may to have the sound leveled in soundbooth after all is there something to measure the channel settings on the bmcc with the mixpre...so when ill see the mixpre levels around -9db than its exactly that on the camera too after all, the channel inputs settings volumes for ch1 ch2 is the volume of how loud it will be recorded, right?
so yeah , pretty much that,.

thanks
lex
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Re: Frequently Asked Questions - Audio

PostMon Mar 03, 2014 8:24 pm

.
Last edited by Göran Diffner on Sun Jun 15, 2014 2:46 pm, edited 1 time in total.
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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostThu Apr 17, 2014 4:10 pm

Hi,

i have a little problem with the audio.
I am using the pre-mix D, BMCC EF, EVF Alphatron, Sennheiser ME 66.
Line out, Line in, CH 1 input 85 %.
The voices sounds not bad, but:
all the time the metering in the evf shows me an input of sound,
even without talking. Green, not yellow or red. But there is nothing to hear.

I put it in my Avid MC 6: everything is quit, but it shows -28 db sound

My test with CH 1 input 63%: -31db without sound.

I put the potis on the pre-mix to zero= evf metering shows nearly full green column
Only going down to CH 1 input 0 % helps....

What is my mistake... ?

Thanks

Olaf
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Chris Hocking

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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostThu Apr 17, 2014 10:11 pm

What firmware are you running Olaf?

This thread may help: viewtopic.php?f=2&t=17104
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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostFri Apr 18, 2014 7:23 pm

Hi,

today I load the new 1.7.

The metering in the EVF seems now to work right.
Next days I will hear it in the avid.

Thanks

Olaf
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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostMon Apr 21, 2014 12:21 pm

Hi Chris,

I have been a sound man for a long time, starting in the '70s with Nagras and Uhers, so working with the stuff you have now is really a breeze.

There's one thing though that is usually not considered too important, and for me it is: the 1/8" mini-plug interface. That is a connection, particularly the socket, which should be treated and preserved with a lot of respect, because it will eventually fail. This is not something that MIGHT happen, it WILL happen.

The problem are the internal socket springs, that are too small and eventually get metal-fatigue and become intermittent.

There are two solutions for that: using a threadable locking 1/8" socket (which almost NOBODY uses) and using a permanently plugued short cable (1 or 2 feet), with a "serious" connector at the other end, preferably a XLR-3 or 1/4" plug or socket.

I have been advocating this on several topics on several forums, and hopefully someone will listen and do it.

Another thing which should be explained and implemented more thoroughly is level alignment and level settings, particularly when you are using external sources to feed into the BMCC (2.5K or 4K) or BMPCC.

In the old days we used a continuous sinusoid tone (400Hz, 800Hz or 1000Hz) to align the meters in the whole chain. It was a very useful procedure which unfortunately is now lost.

Some of you may remember that reference level, when using VU meters, as 0dB, though some set levels at -4dB to avoid clipping. Modern digital equipment do not use such scales anymore, and now go from -70 or -60dB to 0dB. This 0dB should never be confused with the 0dB on old VU meters, and it should NEVER be exceeded.

So it seems to have become a norm that the reference level is now between -12dB to -9dB. There's a mark at the level sometimes, like a small triangle, and levels should barely exceed that.

At the same time, being "too safe" and leveling everything too low would waste bits that are there to be used.

What you can do, and some multi-track recorders allow that, is setting one or two tracks at say -20dB less level than the "main ones", as protection, so in case there's a clip you will be able to use those protection tracks to recover the clipped parts.

If you have only two tracks you would lose one channel, if you are feeding separate microphones.

There are more suggestions I would like to share.
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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostMon Apr 21, 2014 10:50 pm

carlmart wrote:There's one thing though that is usually not considered too important, and for me it is: the 1/8" mini-plug interface. That is a connection, particularly the socket, which should be treated and preserved with a lot of respect, because it will eventually fail. This is not something that MIGHT happen, it WILL happen.

The problem are the internal socket springs, that are too small and eventually get metal-fatigue and become intermittent.

There are two solutions for that: using a threadable locking 1/8" socket (which almost NOBODY uses) and using a permanently plugued short cable (1 or 2 feet), with a "serious" connector at the other end, preferably a XLR-3 or 1/4" plug or socket.


While I'll agree that it's not quite as sturdy as an XLR, and I have, on rare occasion seen 1/8" sockets fail - they're pretty darn tough, and I don't think it's something to loose sleep over. I have guitar, music keyboards, mixers and patch bays with 1/8" sockets that are constantly being connected and disconnected, and haven't ever had an issue. I think there's far more chance of the camera becoming out-dated and useless than the amount of time it would take to break the camera's 1/8" sockets.

Having said that, I do follow your advice and have a short patch cable that's permanently connected to the camera, so that rather than constantly disconnecting and reconnecting the two 1/8" jacks and headphone jack, I just have to connect a single XLR, that runs down a loom to our mixer and/or recorder.

carlmart wrote:I have been advocating this on several topics on several forums, and hopefully someone will listen and do it.


Blackmagic have put XLRs on the URSA - so apparently they do listen!

carlmart wrote:Another thing which should be explained and implemented more thoroughly is level alignment and level settings, particularly when you are using external sources to feed into the BMCC (2.5K or 4K) or BMPCC.


Until BMD enables software meters via a firmware update, you can easily use UltraScropes to line up your external mixer/recorder to the BMCC/BMPCC. The URSA obviously has massive physical meters on the side of the camera, so that solves that problem.

carlmart wrote:There are more suggestions I would like to share.


Awesome - fire away!
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Nas

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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostThu Apr 24, 2014 3:25 pm

Hi Chris,

I'm about to start shooting an independent feature film in North Africa and i wanted to ask you what you would suggest as a set-up for recording sound separately from the Blackmagic Production camera 4k? I'm not very technical on sound, but i understand that there is a serious problem because of no timecode for separate recorded sound. We are planning to use FCP for post production, you mentioned in the FAQ that:
1- we need to connect with a cable our timecode generator signal to one of the two audio inputs on the camera. Which kind of cable?

2-we need to use an external plug like AuxTC reader.

Does this set up works easily for many hours of sound recording for a feature film?

Cheers,

nas
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Carlos E. Martinez

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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostThu Apr 24, 2014 9:04 pm

Are we talking of a sound person working away from the camera or linked to it?

What will you be using as a recorder?

How many mics will you manage?

Will you have a sound person and a mic man, or just one doing both?

Whatever the camera, IMHO you can go two ways for the sync:

1) Use two portable TC generators, the smaller you can get, and sync them at least two times a day.

2) Use one TC on the recorder and wire the TC to it. Use just a Rode or similar mic on the camera, going into the other channel.

When you get back use Plural Eyes or AMA to sync the tracks.
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Chris Hocking

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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostThu Apr 24, 2014 10:12 pm

Nas wrote: I'm not very technical on sound, but i understand that there is a serious problem because of no timecode for separate recorded sound.


My advice - hire a professional sound recordist. I've worked on countless low/no-budget feature films, and I can't stress how important getting good on-location audio is. So many potentially good independent features end up on the directors bedroom shelf because they failed to get good location audio, and don't have the budget to pull off decent ADR. Sound is 50% of everything you see in the theatres - so don't skimp. Whatever you've budgeted for lenses, I'd budget the same for microphones.

However, if you already have a great sound recordist on board, then my suggestion would be to record a guide track on the left channel of the BMP4K and timecode on the right channel.

Assuming you're using a decent audio recorder, I'd just sync your audio recorder to a timecode box (such as a Lockit Sync Box, Betso SBOX-1, Denecke SB-3, Timecode Buddy, etc.), and connect the timecode box to the right input of your camera.

Alternatively, if you don't have access to the timecode box, you can just use a wireless transmitter (any audio transmitter will do) to send the timecode signal constantly from the audio recorder to the camera.

Although you can get away without it, I'd probably recommend putting something like the juicedLink BMC388 on the camera.

So, in a perfect scenario you'd have the BMC388 connected to the camera, then a guide track from your sound recordist wireless transmitted to the left channel of the camera, and the timecode track from your sound recordist sent to the right channel (either wirelessly or via a sync box). You could then use something like AuxTC reader to automatically sync the footage, and if something goes wrong, you can always use PluralEyes as a backup.

My suggestion though - don't use FCP7. It's dead. Time to move on. I'd seriously consider using FCPX, Premiere CC or Avid. Yes, you can make FCP7 work - but it's really not great at long form. If it was my film - I'd use Avid, no question, because Avid is really the king of long-form.

If you're audio recorder doesn't have a timecode output function - stop now, and consider hiring a proper sound recordist. You don't want to spend months/years working on a feature film that's doomed from the start because you failed to invest in decent sound early on.

Time blog post may be of some interest: http://latenitefilms.com/blog/waiting-on-sound/

Hope this helps!

Chris!
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Carlos E. Martinez

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Re: Frequently Asked Questions - Audio (Updated: 9/4/14)

PostThu Apr 24, 2014 11:53 pm

Chris,

On different words I think we advised practically the same, didn't we? :D


Carlos
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Larry Price

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Re: Frequently Asked Questions - Audio (Updated: 01/05/14)

PostThu May 08, 2014 3:17 pm

Hi Chris;
I followed your instructions for double-system editing into the BMPCC almost to the letter. In this case 'almost' had an entire alphabet attached to each letter.
I hooked up the Rode Video Mike to the Tascam 100 MkII via mini to XLR adapter
Hooked up a Shure lav to the other XLR
Turned on the Tascam, made sure to push the record button twice, once for standby one for record.
Signals showed up on both tracks. Put on the headphones. Had sound.
Turned on the camera, started to conduct the interview.
Now the tricky part.
A.) In the rush to set up all this stuff and get to the interview with the impatient interviewee I neglected to attach the cable from Tascam to Camera. No biggie as I had the sound on the card. Still one alphabet to the letter A in almost.
B.) When I finished the interview, wrapped, went to the computer, copied the files from the memory card of the Tascam to the HDD, and the .mov from the BMPCC to the HDD, and imported all to FCPX (and later FCP)
I had a bit of a surprise. Another few alphabets to the Almost. The Tascam only recorded one minute, while continuing to show it was recording the entire 45-minutes. (No idea why this happened. I put the Tascam on to charge all night but it showed a battery failure after a few minutes of recording, then I hooked up the external power supply. Perhaps then something happened in the Tascam and while it showed recording actually had stopped. Is this possible?)

C.) So I'm stuck with the BMPCC sound track. Filled with crickets and lots of noise. Useable only if it is sound of a murder caught live and exclusively for some tv news station.

D.) I imported the mov file into SoundTrack Pro, exported a .wav and then opened another file and imported the .wav. Then applied filters, noise reduction, hum reduction, etc., in hopes of getting better sound.

What did happen was the volume increased significantly, and some of the chirping decreased.

E.) I then reimported that file into FCPX and laid it beneath the video, synched it up. Better sound than the original but still very far from good. Closer to useable in a doc if absolutely necessary, I guess.

F.) Besides cursing BM for lousy sound capabilities in the camera, and myself for not buying a different camera, or turning on my Canon HV20 wired with mic as a backup while shooting, I wondered if perhaps you have any advice for the likes of idiots like me who don't take a soundman.

G.) And also, in the future, if I'm not better off buying either a Rode Video Mic pro or a juicebox with pre-amp and meters to use with the camera. I find that with the Mics, the Camera, the Lenses, the Tascam, and the Monitor, I am using so many pieces of equipment I open myself up to technical problems.

H.) A friend just did a show for CNN, 8 part series, shot 64 hours, using the Canon c300 and a monopod. Of course that camera cost a fortune, but in the long run is easier for a one-man band.

Sorry for the long tiresome retelling of the ordeal.

I.) Any advice appreciated.
Thanks,
LP
Larry Price
documentary filmmaker
Price Communications, Inc.
Jerusalem
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Carlos E. Martinez

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Re: Frequently Asked Questions - Audio (Updated: 01/05/14)

PostThu May 08, 2014 4:05 pm

Chris,

Until we get (if we ever do) a VU meter scale on the BMPCC screen, where can I get a scale of values corresponding to a digital metering.

Can we assume that the BMPCC adjusts to the standard 0 on VU meter, which is equal to +4 [dBu], or 1.228 volts RMS across a 600 ohm load?

If so, does it adjust to the figure below?
Attachments
dB vs dBFS.jpg
dB vs dBFS.jpg (14.84 KiB) Viewed 53325 times
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Re: Frequently Asked Questions - Audio (Updated: 01/05/14)

PostThu May 08, 2014 4:07 pm

I know it's probably to late anyway... but did you try to use a file-recovery programm on tascams memory card? I had a similar problem on my H4 a couple of years back, after recording for almost 2 hours straight the batteries died and left the card with only one zero byte empty file... After a lot of swearing (i had no usable camera audio, as i was shooting from behind a crowd while the H4 was on stage, hidden from the audience) i tried several "file recovery" programms and finally managed to extract an almost complete recording (the last seconds were corrupt, right before the batteries went out). Obviously the recorder stored the data to the card, but as it couldn't finish the recording, no directory entry was created, and the recovery program fixed it. I would have been tared and feathered otherwise... (ok, not quite, it was "only" a school performance which i recorded pro bono, yet still, the shame, ...).
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Re: Frequently Asked Questions - Audio (Updated: 01/05/14)

PostTue Jun 24, 2014 2:23 pm

How's the frequency response with v1.8. Is it fixed? Not had chance to test as I'm away.
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Re: Frequently Asked Questions - Audio (Updated: 01/05/14)

PostTue Jun 24, 2014 2:33 pm

Just seen Tom's tests send it would appear all is well in the audio arena now, although I await to see if there have been any sacrifices. Noise floor seemed higher but that could be due to a new reworked gain mapping.
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Chris Hocking

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Re: Frequently Asked Questions - Audio (Updated: 01/05/14)

PostWed Jun 25, 2014 8:26 am

Tim Callaghan wrote:How's the frequency response with v1.8. Is it fixed? Not had chance to test as I'm away.


Here's a visual comparison:

Image
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Darko Djerich

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostSun Jun 29, 2014 11:42 am

Had bit of play with audio in 1.8 firmware and I found it very usable.
Run 416 through Behringher Ultragain Pro 48 preamp,had to push 50db gain and line input upto 82% to get
good signal.

ME66 was hotter and had lots of signal to play with without pushing gain so much on preamp.
However when plugged to mic input level,audio levels were very strong and was able to get good signal
with only 25db gain and 20% mic level input.
However line level sound seemed to be bit richer sound with less noise.

SD Mixpre D is on its way from Melbourne on Monday so that will change things for the better I hope again .
Very confident at the moment to use sound from BMCC for doco,web,interview situaton and headphones monitoring was pretty clear with Sennheser HD280 Pro with very little noise.

I am pleasantly surprised and consider audio to be very usable now,will post short video with sound recorded from 416 in day or two.
Also found the led levels from Ultragain Pro preamp to perfectly match audio levels from BM Media Express software
which I ran live via Ultrastudio USB 3 SDI wich also provided nice large enough monitor with great preview ,lot better quality then BMCC screen,found it more helpful then Resolve Live for monitoring.(in resolve just monitor scopes then flick to Express)
Artist
Creative Film Enterprises
creativefilm.com.au
imac5k i7 32gb 2017 video assist 4k mbp mid 2015 r9 370x phase one 645df/p40+,ursa mini4.6 ef bmcc ef bmpcc micro panel ronin mx dji phantom 2 hero 3 black zenmuse 3d...sleepless nites...
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Frank Glencairn

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 9:40 am

Darko Djerich wrote:However when plugged to mic input level,audio levels were very strong and was able to get good signal
with only 25db gain and 20% mic level input.
However line level sound seemed to be bit richer sound with less noise.



Interesting, usually the "line" is the same like the "mic" input, but with a padding in front of it, to bring down the hotness of the signal (to mic level) - so on paper it should sound the same.
But Chris knows much more about that stuff than I do.

Anyway, I'm more than happy, that the internal audio now is 100% usable without the need of post processing.
http://frankglencairn.wordpress.com/

Set your zebras to 100%, ETTR and you're golden - and NO, you can't use TB as output for an external monitor, and you can't download the footy via TB ether.
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Carlos E. Martinez

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 9:48 am

It usually is like you said, Frank, though sometimes the line option bypasses one stage. At least that's what good design recommends.

But if you have a look at those weird curves, who knows what they are doing inside the BMPCC...

One thing I do know: if you feed good audio levels and select the "right" gain, you can get excellent audio from the BMPCC. The problem is alignment.

I'm working on a design that might solve all that, but people will have to follow certain procedures.
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Frank Glencairn

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 9:50 am

Can't wait to hear with what you are coming up.
http://frankglencairn.wordpress.com/

Set your zebras to 100%, ETTR and you're golden - and NO, you can't use TB as output for an external monitor, and you can't download the footy via TB ether.
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Carlos E. Martinez

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 10:08 am

Frank,

Just sent a PM to you.
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Darko Djerich

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 12:56 pm

Hi guys,


here I ran quick test with 416 and ME66 USING 1.8 firmware and SD Mixpre D(newly arrived).

No EQ,Lo Cut filters used, files are as recorded and no manipulation was used at all.
Levels monitored via Media Express on laptop,3-4 feet away from mic distance to mic.


https://soundcloud.com/darko-djeric/bmcc-416-mixpre-d-line-levels-test-1-fav

https://soundcloud.com/darko-djeric/bmcc-416-mic-levels-sd-mixpre-d-test-2

https://soundcloud.com/darko-djeric/bmcc-me66-mixpre-d-mic-level-test-3

https://soundcloud.com/darko-djeric/bmcc-me66-line-levels-sd-mixpre-d-test-4

These are so far best settings found that work for me, also files can be downloaded there.

Cheers
Artist
Creative Film Enterprises
creativefilm.com.au
imac5k i7 32gb 2017 video assist 4k mbp mid 2015 r9 370x phase one 645df/p40+,ursa mini4.6 ef bmcc ef bmpcc micro panel ronin mx dji phantom 2 hero 3 black zenmuse 3d...sleepless nites...
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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 3:49 pm

Frank Glencairn wrote:Interesting, usually the "line" is the same like the "mic" input, but with a padding in front of it, to bring down the hotness of the signal (to mic level)

Are you sure about that? All mixer designs I know, have an additional preamp-stage for the Mic while line is fed directly into the input amplifier. Maybe my knowledge is outdated as the time when I dealt intensively with mixer designs is "a few" years back. But what I hear in my tests with the BMCC I would say Line has less noise and therefor is probably not a simple pad. But I may be wrong.

Johannes
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Christopher Barry

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Jul 02, 2014 5:37 pm

Darko Djerich wrote:Hi guys,


here I ran quick test with 416 and ME66 USING 1.8 firmware and SD Mixpre D(newly arrived).

No EQ,Lo Cut filters used, files are as recorded and no manipulation was used at all.
Levels monitored via Media Express on laptop,3-4 feet away from mic distance to mic.


https://soundcloud.com/darko-djeric/bmcc-416-mixpre-d-line-levels-test-1-fav

https://soundcloud.com/darko-djeric/bmcc-416-mic-levels-sd-mixpre-d-test-2

https://soundcloud.com/darko-djeric/bmcc-me66-mixpre-d-mic-level-test-3

https://soundcloud.com/darko-djeric/bmcc-me66-line-levels-sd-mixpre-d-test-4

These are so far best settings found that work for me, also files can be downloaded there.

Cheers


Plenty of level there, Darko. I am now finding the balanced XLR Line out of MixPre-D to the BMCC via balanced 1/4" jacks at Line level input sounds best. More testing for me on the weekend.
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Frank Glencairn

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostThu Jul 03, 2014 8:04 am

Johannes Hoffmann wrote:Are you sure about that? All mixer designs I know, have an additional preamp-stage for the Mic while line is fed directly into the input amplifier.


No, I'm not sure. I know just enough about audio (let alone electronics) as a DP needs to know.
Usually I leave this stuff to my sound guy. What I said is, what Robert (from JuicedLink) said about it in one of his videos - cant remember if that applied just to the BMCs or to any audio gear though.
http://frankglencairn.wordpress.com/

Set your zebras to 100%, ETTR and you're golden - and NO, you can't use TB as output for an external monitor, and you can't download the footy via TB ether.
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David Green

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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostThu Jul 03, 2014 8:39 pm

Frank Glencairn wrote:
Johannes Hoffmann wrote:Are you sure about that? All mixer designs I know, have an additional preamp-stage for the Mic while line is fed directly into the input amplifier.


No, I'm not sure. I know just enough about audio (let alone electronics) as a DP needs to know.
Usually I leave this stuff to my sound guy. What I said is, what Robert (from JuicedLink) said about it in one of his videos - cant remember if that applied just to the BMCs or to any audio gear though.


It varies by input design cost.
Cheap inputs use a resistor, such as a 47k ohm, that is switched into the signal path in series, to attenuate the signal level. It works, but not very well.
Good inputs using a single combination mic/line connector will switch an additional op-amp stage in front when mic is selected.
Good inputs using independent mic and line connectors use independent op-amps tailored for each input type.

The biggest issue with almost every mic pre/mixer system available for portable use is the battery system. They will typically never provide good "studio quality" mic pre's with high gain and low noise if they only use 2 or 4 or 6 AAs or a single 9V battery, +/- 15V rails are pretty much required. Using small, low voltage, low current, batteries will also have reduced life when phantom power is on since they will be forced to use a 48 volt DC-DC converter which will eat batteries.
David R. Green - Author Composer Filmmaker Programmer
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Re: Frequently Asked Questions - Audio (Updated: 25/06/14)

PostWed Aug 20, 2014 5:02 am

The OP's explanation of balanced audio is incorrect. What he describes is differential signalling. Not all balanced audio uses differential signalling. The cold output can carry no signal, instead of a polarity reversed signal, and that's still balanced. The noise rejection of balanced audio comes from the hot and the cold being impedance balanced and the use of a differential amplifier.
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