Pocket 4K - weak preamps?

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

Al Slamecka

  • Posts: 31
  • Joined: Mon Aug 12, 2013 4:35 pm
  • Location: Atlanta, GA

Re: Pocket 4K - weak preamps?

PostTue Jan 15, 2019 4:54 am

Subsequent to my earlier post about potential audio noise issues related to 1) power draw on the battery and 2) a lot of white noise when using phantom power, I happened across a recent favorable review on Provideocoalition.com about the SS-1 mic preamp from The Simply Sound Company.

The SS-1 is an 'pre' preamp device that sits inline between a dynamic mic and a device's preamp. It's powered by 48v phantom power coming from the device (BMPCC 4K in this instance) and provides +27dBu gain boost to the mic's signal. It doesn't work with condenser mics however it works with both dynamic and battery powered mics (XLR connection required).

I ordered the SS-1 direct from The Simply Sound Company for US $60 and can confirm that it does boost the signal of my Sennheiser MKE600 considerably, allowing me to turn down the gain of the BMPCC 4K preamps. To be clear, the Sennheiser still needs to be using battery power as the SS-1 does not pass phantom power to the mic.

From a couple brief tests, I believe the signal should be sufficient in most normal conditions with the BMPCC 4k preamps at 30% - 40%. On the down side, the white noise issue is still prevalent however the expected electronic noise from powering preamps, SSD, and the SS-1 with the battery is not there! Perhaps something about powering the MKE600 directly thru phantom power had something to do with the noise I reported earlier. The other drawback of using the SS-1 is that it adds about 4" in length to the mic. My pocket camera is getting less and less 'pocket' with each workaround.

So I think I have two 'ok' solutions... powering the MKE600 via it's internal battery with BMPCC 4K phantom power turned off (quietest solution) or using the SS-1 in-line with MKE600 where the mic still uses it's own power but the SS-1 is powered by BMPCC 4k phantom power (still too noisy).

Either way - BMD needs to determine if they can boost the gain of the XLR (and 3.5mm) internal preamps as an external preamp should not be required to record a decent level. And they should look into the noise that appears to be generated when using phantom power... even at 30% gain levels.
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostTue Jan 15, 2019 5:02 am

I really beginning to suspect that Blackmagic designed the camera around two types of users. The first is the type that will use the camera in its absolute minimal configuration, relying on the built-in speakers to record all audio. The second is the type that will rig up the camera and use separate audio recorders and, at best, use the camera's audio for nothing more than an audio reference signal or timestamp.

I can't see any other reason for such poor microphone support, compared what you can get with just about any other camera.
https://australianimage.com.au/
Offline

Steve Golding

  • Posts: 82
  • Joined: Sun Dec 22, 2013 1:57 am

Re: Pocket 4K - weak preamps?

PostTue Jan 15, 2019 6:31 am

And since they copped such a lot of crap for it last time, why do it again.

Steve
Offline

Justin Jackson

  • Posts: 606
  • Joined: Thu Apr 28, 2016 3:50 am

Re: Pocket 4K - weak preamps?

PostSat Jan 19, 2019 10:39 pm

I agree with the assumption that the designers of the BMPCC4K assumed with such an incredible price point, that the majority using it for either Indie or Broll would not use the mics at all, or if anything as a syncing track to the external audio. With Timecode capability and that you can get good audio recorders or a separate TC generator for not too much more, I would agree that the design was centered around video quality, (especially given that they were working on BRAW the whole time this camera was being built and knew it would be part of it eventually).

That said, probably would have been better to not add the mini XLR and just leave a basic 1/8" input. I would have rather have seen an SDI input over HDMI if that were possible and no XLR. Just my thoughts. I picked up an SD mixpre 10T with intentions of using external audio and TC input so I am not worried about the audio problems personally. But I do wish it worked for those that want it.
Custom DIY AMD1950x 16-core/32-thread, liquid cooled, 64GB 3600Mhz RAM, 950Pro-512GB NVMe os/apps, 2x500GB 850 Evo RAID 0 SATA3, Zotac 1070 8GB video, USB 3.1Gen2 RAID0 2x4TB, 2x2TB Crucial MX500 SSD SATA3.
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostSat Jan 19, 2019 10:50 pm

Justin Jackson wrote:That said, probably would have been better to not add the mini XLR and just leave a basic 1/8" input. I would have rather have seen an SDI input over HDMI if that were possible and no XLR. Just my thoughts. I picked up an SD mixpre 10T with intentions of using external audio and TC input so I am not worried about the audio problems personally. But I do wish it worked for those that want it.


Yes, I'm not really sure what the point of the mini-XLR is if it has the same issues as the 3.5mm, which I understand it does. At least the 3.5mm could have had a power option. I'm happy with the HDMI and maybe an SDI in lieu of the XLR would have been better. HDMI allows for more options with such things as field monitors.
https://australianimage.com.au/
Offline

Justin Jackson

  • Posts: 606
  • Joined: Thu Apr 28, 2016 3:50 am

Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 12:29 am

Yah, def with HDMI. Only thing I dislike is the worry of HDMI being yanked and possibly breaking the plug in the camera. On the other hand, SDI with locking might end up with the camera itself flying and landing/breaking.. so who knows whats better. I go back and forth on using HDMI clamp.. if someone trips and pulls it out, I lose a little footage.. but if its clamped in.. my whole rig could get knocked over and cause untold damage to it, and possibly injure someone too. I am starting to learn towards the idea.. and I tried this but had varying degree of success.. a small 6 inch HDMI cord with female end that is then plugged in to.. and that cord is clamped in place... but if anyone trips/pulls, the main cord plugged in to it could be pulled out, so that hopefully the rig is not pulled with it AND it protects/saves the HDMI plug of the camera. I DID this exact thing for my other setup (to my Atomos Inferno) and it worked for a bit, but then I started having odd video connection issues, wiggling the small cord seemed to be the problem so when I took it out of the equation, everything was fine again.

Really wish we could find some really high quality cables that were durable. I would pay a LOT more money to buy a couple of those that would last a long time and work well. Seems only thing you can find is cheap cables that may or may not work.
Custom DIY AMD1950x 16-core/32-thread, liquid cooled, 64GB 3600Mhz RAM, 950Pro-512GB NVMe os/apps, 2x500GB 850 Evo RAID 0 SATA3, Zotac 1070 8GB video, USB 3.1Gen2 RAID0 2x4TB, 2x2TB Crucial MX500 SSD SATA3.
Offline

Denny Smith

  • Posts: 10430
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 2:04 am

Zigen 4K high bandwidth cables come I; round and flat, are very flexible, and holdup. Additionally, the HDMI connector locks in for a secure fit. They are available from B&H.
Cheers
Last edited by Denny Smith on Tue Jan 22, 2019 5:46 pm, edited 2 times in total.
Denny Smith
SHA Productions
Offline
User avatar

Peter J. DeCrescenzo

  • Posts: 2238
  • Joined: Wed Aug 22, 2012 6:53 am
  • Location: Portland, Oregon USA

Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 8:35 am

I'm testing a relatively inexpensive Tascam DR-10X (which I've had for awhile) with my new Pocket 4K. Seems to work well as a mic pre-amp for the cam. And obviously it can also be used as a standalone audio recorder.
https://www.bhphotovideo.com/c/product/ ... inear.html

The DR-10X is extremely small & lightweight, can be powered by an internal AAA battery or externally via USB, has a full-size XLR input, flexible features, and nice sound quality. As the unit does not output XLR phantom power, the audio source must be self-powered. (I'm using it with a Sennheiser ME-64 w its power module). Connects to the Pocket via a 1/8" (3.5mm) mini TRS cable, or an appropriate mini-XLR-to-3.5mm-TRS adapter cable.

IMHO the downside of the DR-10X is its tiny tiny buttons which are colored black on black (!), making them difficult to see. But once the unit is configured, and especially if powered via USB, it can operate for many many hours (as a preamp) without fuss.

I use a IndiPro D-tap to USB power adapter when not powering the DR-10X via an internal AAA battery:
https://www.bhphotovideo.com/c/product/ ... to_5v.html

I made the following (boring!) video with the soundtrack recorded using the above hardware. Listen to the soundtrack and refer to the Vimeo page for details. ProRes LT 1080p "film" recording was edited in DR15.2, but the soundtrack is unchanged from the original recording (no audio adjustments were made in DR15.2).
Last edited by Peter J. DeCrescenzo on Mon Jan 21, 2019 2:44 am, edited 4 times in total.
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 9:38 am

Interesting. What sort of audio levels are you getting and from what distances? I looked at the specs and they don't appear to be much different from the basics of what the LS-14 offers which, on it's own, doesn't amplify sufficiently for anything but relatively close subjects.
https://australianimage.com.au/
Offline
User avatar

joe12south

  • Posts: 397
  • Joined: Tue Jan 16, 2018 4:14 pm
  • Location: Nashville, TN
  • Real Name: Joseph Moore

Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 6:33 pm

Al Slamecka wrote:The SS-1 is an 'pre' preamp device that sits inline between a dynamic mic and a device's preamp. It's powered by 48v phantom power coming from the device (BMPCC 4K in this instance) and provides +27dBu gain boost to the mic's signal.

Thanks for this tip. A very useful little bit of kit.
Pocketluts: Purpose-built LUT system for the Black Magic Design Pocket Cinema Camera 4K
http://www.pocketluts.com/
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostSun Jan 20, 2019 7:55 pm

Four or so years ago the same design device was available for 3.5mm inputs, but for some reason was discontinued, perhaps because camera manufacturers started implementing powered 3.5mm microphone inputs.
https://australianimage.com.au/
Offline

Wayne Steven

  • Posts: 1798
  • Joined: Thu Aug 01, 2013 3:58 am
  • Location: Earth
  • Warnings: 1

Re: Pocket 4K - weak preamps?

PostMon Jan 21, 2019 3:14 am

Hi. If BM could make the camera activate and control wireless and USB interface audio recording devices (through normal standards, even if any audio over WiFi, through USB dongle or card, exists). Leaving our strong 7Gb/s WiFi I feel is a mistake. But external control of USB devices would be a great Quality enhancement.

It also means pickup and internal camera recording if sound from the device might be possible.
Often people deceive themselves so much they do not understand, even when the truth is explained to them.
Offline

Leon Benzakein

  • Posts: 917
  • Joined: Thu Aug 15, 2013 3:40 pm

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 4:42 pm

Peter J. DeCrescenzo wrote:I'm testing a relatively inexpensive Tascam DR-10X (which I've had for awhile) with my new Pocket 4K. Seems to work well as a mic pre-amp for the cam. And obviously it can also be used as a standalone audio recorder.
https://www.bhphotovideo.com/c/product/ ... inear.html

The DR-10X is extremely small & lightweight, can be powered by an internal AAA battery or externally via USB, has a full-size XLR input, flexible features, and nice sound quality. As the unit does not output XLR phantom power, the audio source must be self-powered. (I'm using it with a Sennheiser ME-64 w its power module). Connects to the Pocket via a 1/8" (3.5mm) mini TRS cable, or an appropriate mini-XLR-to-3.5mm-TRS adapter cable.

IMHO the downside of the DR-10X is its tiny tiny buttons which are colored black on black (!), making them difficult to see. But once the unit is configured, and especially if powered via USB, it can operate for many many hours (as a preamp) without fuss.

I use a IndiPro D-tap to USB power adapter when not powering the DR-10X via an internal AAA battery:
https://www.bhphotovideo.com/c/product/ ... to_5v.html

I made the following (boring!) video with the soundtrack recorded using the above hardware. Listen to the soundtrack and refer to the Vimeo page for details. ProRes LT 1080p "film" recording was edited in DR15.2, but the soundtrack is unchanged from the original recording (no audio adjustments were made in DR15.2).


Following on Peter's post.

I wonder how well this Tascam DR-10L with 3.5 mm plug (Digital Audio Recorder with Lavalier Mic (Black)) would work with a Rode VideoMicro plugged in, using Peter's work flow.

https://www.bhphotovideo.com/c/product/ ... order.html
Television: Lighting/Cameraman, O.B. Camera Operator, Grip, Lamp Operator
Film: Grip, Lamp Operator
Theater: Lighting Designer, Light board Operator, Stage Electrician, Stage Management
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 7:54 pm

Leon Benzakein wrote:I wonder how well this Tascam DR-10L with 3.5 mm plug (Digital Audio Recorder with Lavalier Mic (Black)) would work with a Rode VideoMicro plugged in, using Peter's work flow.


Given everything that I've tried, I strongly suspect that without an amplifier, it's not going to provide strong recording levels. This device sounds interesting, but not yet available: https://sxfi.com/.

https://australianimage.com.au/
Offline
User avatar

Peter J. DeCrescenzo

  • Posts: 2238
  • Joined: Wed Aug 22, 2012 6:53 am
  • Location: Portland, Oregon USA

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:22 pm

I haven’t used a Tascam DR-10L, but it appears to be very similar to the DR-10X I demonstrate above. My guess is it probably works equally well with the Pocket 4K cam’s mini TRS audio input.

Two points: 1/8” (3.5mm) TRS connectors aren’t very reliable and tend to cause static/crackle when moved or bumped. Also, the cable lengths are best kept short; typically 3’-6’ or less.

The purpose of my test above was just to hear what my DR-10X sounds like via the Pocket 4K 3.5mm input. I’m far more likely to use the cam’s mini-XLR input, subject to further testing. (My adapter cable arrives later today.)
Offline

Leon Benzakein

  • Posts: 917
  • Joined: Thu Aug 15, 2013 3:40 pm

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:32 pm

Ray,
I could not use the Youtube link posted.
I did find the unboxing video for this product.

I am not sure how one would use this in a camera application since it seems to be app driven and has a USB-C input.
Television: Lighting/Cameraman, O.B. Camera Operator, Grip, Lamp Operator
Film: Grip, Lamp Operator
Theater: Lighting Designer, Light board Operator, Stage Electrician, Stage Management
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:33 pm

Peter J. DeCrescenzo wrote:The purpose of my test above was just to hear what my DR-10X sounds like via the Pocket 4K 3.5mm input. I’m far more likely to use the cam’s mini-XLR input, subject to further testing. (My adapter cable arrives later today.)


That will be interesting. I gave up even looking for a mini-XLR adapter because it seemed that it wouldn't really improve things. The thing is, no one on YouTube (that I can find) has done any sort of tests like I did to see how far you can go and still get reasonable sound through a powered/unpowered mic.

This is the second of a series of tests (1-10 metres at 1 metre intervals) where I changed numerous settings to see what sort of sound levels I could record (earphones needed for best results):
.
https://australianimage.com.au/
Offline

Leon Benzakein

  • Posts: 917
  • Joined: Thu Aug 15, 2013 3:40 pm

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:36 pm

Peter,

Looking forward to your future test.
Television: Lighting/Cameraman, O.B. Camera Operator, Grip, Lamp Operator
Film: Grip, Lamp Operator
Theater: Lighting Designer, Light board Operator, Stage Electrician, Stage Management
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 8:53 pm

Leon Benzakein wrote:Ray,
I could not use the Youtube link posted.
I did find the unboxing video for this product.

I am not sure how one would use this in a camera application since it seems to be app driven and has a USB-C input.


I never know why some links work and other don't. You may have to search on the product and add CES, which is where it was reviewed.

You can get USB-C to 3.5mm adapters, so I don't think that would be a problem. I use a Creative USB 3.1 to 3.5mm adapter with my PC to pass a signal to my amplifier and it works great.

The app is only required if you want the full experience. I think the product will work as an amplifier on its own, which if it does and given its size, would be great.
https://australianimage.com.au/
Offline
User avatar

Robert Niessner

  • Posts: 2207
  • Joined: Thu Feb 21, 2013 9:51 am
  • Location: Graz, Austria

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 9:04 pm

I'd like to add to this discussion that I'm using a Sennheiser EW100 G3 receiver set to output +12dB and going into the 3.5mm input I get very usable interview audio even with the camera gain set to 50%.
Robert Niessner
LAUFBILDkommission
Graz / Austria
---------------------------------------------------------------------
Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
http://tinyurl.com/pjf6a3m
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 9:47 pm

Robert Niessner wrote:I'd like to add to this discussion that I'm using a Sennheiser EW100 G3 receiver set to output +12dB and going into the 3.5mm input I get very usable interview audio even with the camera gain set to 50%.


If all I wanted to do was interviews, then there really wouldn't be an issue. I guess because of what I want to do, the situation is more problematic. The issue is that I'm a single operator and don't have the luxury of a sound operator to carry around a mic for proper sound recording. This is even more of an issue when out in the open.
https://australianimage.com.au/
Offline
User avatar

Robert Niessner

  • Posts: 2207
  • Joined: Thu Feb 21, 2013 9:51 am
  • Location: Graz, Austria

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 10:26 pm

Well, most of the time I'm a single operator too - doing the lighting, camera, and audio. Either it is a lav mounted to the interviewee or a journalist holding a reporter mic close to the interviewee.
Robert Niessner
LAUFBILDkommission
Graz / Austria
---------------------------------------------------------------------
Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
http://tinyurl.com/pjf6a3m
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostTue Jan 22, 2019 10:45 pm

Robert Niessner wrote:Well, most of the time I'm a single operator too - doing the lighting, camera, and audio. Either it is a lav mounted to the interviewee or a journalist holding a reporter mic close to the interviewee.


Yes, I have two Lav mics and would do similarly, but that's not possible when it comes to most of what I do.
https://australianimage.com.au/
Offline

Leon Benzakein

  • Posts: 917
  • Joined: Thu Aug 15, 2013 3:40 pm

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 12:54 am

Australian Image wrote:I never know why some links work and other don't.


I have had the same experience lately.

I have found that if you right click on the Youtube video, a menu comes up, the top item is COPY VIDEO URL, you left click on that to select, then you go to where you want to insert the link, right click to bring up the menu and then paste.(or ctrl V where you place the cursor)

That has solved the issue for me.
Television: Lighting/Cameraman, O.B. Camera Operator, Grip, Lamp Operator
Film: Grip, Lamp Operator
Theater: Lighting Designer, Light board Operator, Stage Electrician, Stage Management
Offline

Denny Smith

  • Posts: 10430
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:07 am

The best solution to bypass the new Pocket’s “weak” preamps, is to use a proper small mic preamp, like a Sound Devices MixPreD which has a proper impedance 3.5mm TRS connection to the camera to feed a line level level stereo input, or the new MixPre3 which will also record the audio as well. Used MixPreDs are available at reasonable prices.
Cheers
Denny Smith
SHA Productions
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:09 am

The URL is generally fine, but something happens on this site that displays or doesn't display the YouTube video correctly. This is the same video posted again:

https://australianimage.com.au/
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:18 am

Denny Smith wrote:The best solution to bypass the new Pocket’s “weak” preamps, is to use a proper small mic preamp, like a Sound Devices MixPreD which has a proper impedance 3.5mm TRS connection to the camera to feed a line level level stereo input, or the new MixPre3 which will also record the audio as well. Used MixPreDs are available at reasonable prices.
Cheers


That's what my Cayin C5 does and improves the sound levels measurably. But I still have to pass the audio first through my LS-14, with or without a powered mic to get really solid sound pickup.

The MixPre devices may do the same (I've not seen any definitive tests) but they are quite large and very expensive, not the stuff for most run and gun operators. A MixPre3 is nearly as expensive as the BMPCC4K.

Maybe there's a difference between boosting sound from a mic and boosting mic performance, and the latter isn't discussed a lot.
https://australianimage.com.au/
Offline

dsorbera

  • Posts: 59
  • Joined: Thu Nov 29, 2018 10:29 pm
  • Real Name: Daniel Sorbera

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:37 am

After using the Pocket 4k as my main camera for the last few months (got mine mid Nov) I have changed my tune about the preamps.

When using a Sennheiser wireless handheld mic (and sennheiser wireless lavs) into the 3.5mm I generally set the output gain on the wireless pack to +6db or +12db and I'm able to set my in camera level to around 50%-60%.
When plugging into the mini xlr I can set the gain on the rx unit to +0db with the same 50-60% in camera.

When using a rode NTG-2 into the mini xlr I have the in camera level around 85%-90%.

So YES you do have to run it a bit high, BUT it has sounded really good in each scenario. The noise floor seems to be really low even when turned up to 100% in camera, and if I boost it up even higher in premiere it still sounds clean.

I always try to record my audio at -12 anyway and boost in my NLE rather than risk clipping if my talent gets too loud. So for me after a few months of real world use I can say that the preamps have done their job and haven't given me any issues.

I will say that it would be nice to have an auto gain feature that I could turn on when shooting things like sporting events that can get very loud very quickly. It's really easy to clip your audio when things get crazy, and if you set it low enough than you'll be missing things in the quiet moments.
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 4:48 am

This is becoming the most frustrating exercise of all. I went outside to do some more testing and for no known reason I started to pick up the fan noise as a feedback sound. It wasn't the fan, but an electrical noise associated with the fan, pretty much drowning out everything else. For the life of me I couldn't figure out why it started doing this.

So I began removing components, trying different configurations and cables and no joy. And purely by happenstance while I had the headphones on listening to the noise (or feedback) and with everything turned on, I removed the mini-USB connector that was powering the LS-14 and the noise stopped.

The mini-USB connector was a attached to an adapter that went to the V-lock battery 5V outlet, but when I tested the USB connection using a regular mini-USB to USB-A connector on the V-lock, the noise was still there. Why would the USB connector suddenly start inducing noise?

Now I have to use batteries to power the LS-14 until I can figure out what's going on, or start considering an alternative device.
https://australianimage.com.au/
Offline

Michael Kropfberger

  • Posts: 81
  • Joined: Fri Jan 12, 2018 8:27 pm

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 1:39 pm

Hi,
jumping in on that audio level discussion:
my plan is to use the Saramonic UwMic9 lavs and XLR TX with NTG3 in a boom...
bringing the dual-receiver RX straight into the 3.5mm jacks of bmpcc4k

anyone has those?
will the levels be sufficient?

thx
Mike
Intel i7-8700K 3.70Ghz @ 6 cores, 32GB RAM, 1TB M2 SSD (system+media), 1TB SSD (cache), RADEON VII 16GB, Win 10x64 latest
Offline

Leon Benzakein

  • Posts: 917
  • Joined: Thu Aug 15, 2013 3:40 pm

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 4:29 pm

Australian Image wrote:or start considering an alternative device.


Ray

With all the energy that you have put into this(I feel your pain) why do you not look at a Rode Video Mic Pro.

https://www.bhphotovideo.com/c/product/ ... tml?sts=pi
Television: Lighting/Cameraman, O.B. Camera Operator, Grip, Lamp Operator
Film: Grip, Lamp Operator
Theater: Lighting Designer, Light board Operator, Stage Electrician, Stage Management
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 7:53 pm

Leon Benzakein wrote:With all the energy that you have put into this(I feel your pain) why do you not look at a Rode Video Mic Pro.


I've actually considered the VideoMic Pro+, which is reportedly even better than the old Pro; however, it's not functionally any different to the Saramonic, only that it will clearly have better overall audio qualities.

The problem is getting a sufficiently high audio signal to the BMPCC4K for it to be useful. Maybe it's my specific camera that's the issue and not the mics I'm using, but given that the it does work, I kind of dobt that.

I did some further tests yesterday using just the built-in mics with the camera on the rig and the audio was very good, but it picked up everything behind the camera because of the matte box. When using external mics, the signal just doesn't seem to be strong enough to give an equivalent sound level, everything is just muted.

I've got nothing to compare it with, as no one has done any similar tests attempting to record strong and weak ambient sounds outside, it's all vlogging, interview and similar stuff.
https://australianimage.com.au/
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostWed Jan 23, 2019 9:38 pm

I just discovered something really interesting. If I connect the LS-14 to a USB battery bank (for external power) there is no interference noise whatsoever. Connected to the V-lock battery, the noise is intolerable (even with a shielded USB cable).

It's good to know, but what on earth would be causing this?
https://australianimage.com.au/
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostFri Jan 25, 2019 12:28 am

I guess as a final follow-up on this, I did further testing yesterday evening with the Rode VideoMic connected to the Saramonic SR-M3 and the latter going into the Olympus LS-14 audio recorder and then into the Cayin C5 amplifier, and finally into the BMPCC4K (Phew!). I'd do more today, but it's already 38C and rising to at least 42C today (commiserations to those experiencing diametrically opposite temperatures).

Anyway, the audio quality with this setup is excellent, at least for what I need, and the sound pickup of near and far sounds is outstanding. The Rode and Saramonic work together beautifully and it's a pity more mics don't have this option. I know there are devices that combine mics, but they just add bulk and weight.

I'm still not totally happy that I have to turn all of these devices on and off separately. It would be great if there was available a single device that did all of this and would activate and deactivate when the V-lock battery was turned on and off. Though I wouldn't be surprised if there was a device like this, but I'll bet it would be as big as the camera and costs twice as much.

I'm looking forward to doing some real world recording in early February to see how it all comes together.
https://australianimage.com.au/
Offline

quickreactor

  • Posts: 4
  • Joined: Wed Nov 21, 2018 5:42 am
  • Real Name: Barnaby Fredric

Re: Pocket 4K - weak preamps?

PostFri Mar 15, 2019 6:22 am

I received my BMPCC4k the other day, and after putting a cage on it and testing it with my Rode Video Mic Pro, I also feel that the preamp levels are absurdly low on this/my camera.

Rode Videomic Pro (with +20DB switch on) has to be turned up to nearly 100 in camera to get decent audio levels, making it sound awful and noisy. This mic is designed to give a hot signal precisely so that you DON'T have to rely on noisy camera preamps. On my previous Sony and Canon cameras the audio levels would be correct at around 25% or less and the audio much cleaner as a result.

The on camera mics, when turned up to 100%, only go to yellow when I click my fingers loudly point blank in front of them.

I can't help but feel this cannot be working as intended. It may just be selected units, as other people in this thread have had varying opinions. I'm not interested in buying a separate pre-amp, as that is why I bought the Videomic Pro in the first place. For all intents and purposes it has a preamp built in. I have ordered the mini XLR cable and will be testing this shortly.

May I ask if anyone has had any luck talking to support about this yet?
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostFri Mar 15, 2019 7:44 pm

I've gone through this since I received my camera last Oct and have found two solutions. The original was to use a audio recorder in conjunction with a pre-amp and the levels are then fine. You cannot use an audio recorder on its own unless it has a suitable build-in pre-amp.

In the last few days I've found a very inexpensive solution, that works on its own, and which I plan to test out in the next few days. Believe it or not, this device (https://tinyurl.com/y3gu9cte) transforms the audio to a level that no one here is prepared to believe. :D

I bought it off eBay and can be found by searching '8G/16G/32G Digital Voice Recorder 60 Hours Super Long Voice Recording MP3 Player'.
https://australianimage.com.au/
Offline

Johan Cramer

  • Posts: 228
  • Joined: Mon Aug 26, 2013 3:33 pm

Re: Pocket 4K - weak preamps?

PostFri Mar 15, 2019 11:53 pm

For me, the last two firmware updates have largely resolved the issue.

When weak preamplification of microphones is a problem, I would first check whether your BM Pocket 4K has been updated to Firmware version 6.1 or higher.
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostSat Mar 16, 2019 12:50 am

Mine is at 6.2, it makes no difference. It's simply a fact that the 3.5mm input appears to be only designed for pretty much scratch audio. You have to boost the signal to make any 3.5mm microphone worthwhile, powered or non-powered.

I now have two solutions. The first one I know works, and I know the quality, the working range and its reliability. The other works, but I don't yet know the quality, the working range or its reliability. I'm hoping the second one performs as it appears to do, as it solves a lot of other minor issues with the first solution.
https://australianimage.com.au/
Offline

quickreactor

  • Posts: 4
  • Joined: Wed Nov 21, 2018 5:42 am
  • Real Name: Barnaby Fredric

Re: Pocket 4K - weak preamps?

PostSat Mar 16, 2019 2:11 am

@australianimage I have read all your posts about your solutions, very creative! But I do not want to invest in more gear which I have to carry around, mount and power just to make the audio at an acceptable level, this seems to me like an unintended fault.

@Johan Cramer
I am on 6.2 firmware. I honestly think it must differ between different people's cameras. People like Australian Image, me and a couple of others appear to have extra quiet cameras. A friend of mine is getting his camera soon and I will be able to test whether his has higher levels with the same setup. Obviously more testing and proof is required and I will endeavour to provide this in the hopes of a solution.
Offline

pnguyen720

  • Posts: 84
  • Joined: Tue Mar 19, 2019 9:17 pm
  • Real Name: Phong Nguyen

Re: Pocket 4K - weak preamps?

PostFri Mar 22, 2019 2:11 am

I'm glad I found this thread as I'm having the same issue running a Rode VMP.
Offline

Wayne Steven

  • Posts: 1798
  • Joined: Thu Aug 01, 2013 3:58 am
  • Location: Earth
  • Warnings: 1

Components Defects

PostSat Mar 23, 2019 12:59 am

What audio chip do they use? If it is a computer audio chip, the industry is known for shipping low quality chips, particularly seconds, but even high quality they might ship 0.1 percent defect free. Meaning one in a thousand might be defective.

I'm all for setting up automated testing 'rigs' to test and log everything. Place, walk away, come back, read results. Of course, you really want to test the components before assembly, but that gets a bit fiddly.

Saw some amusing stuff the other day comparison between Alexa and Red, Alexa just worked, Red may or may not just work from camera to camera. Some cameras might be fine, some cameras might get random shutdowns etc issues (like stop working). Linus tech tips on YouTube (about 1/4 million didn't getting their Red 8k system) has an YouTube clip on it. Years ago when I heard Red One owners being charge $7k for a new board after their 30 or 90 day warranty expired (not enough for marginal defective components to all brwak down), I gave up wanting to buy a Red One. The defect rate might be 1 cent per component but you pay for a $7000 board exchange, no thanks.

So, looking at those things above, BM cameras seem pretty reliable. It only takes one component out of hundreds in there to produce issues, so it indicates to me there is a low rate of component problems otherwise everything would be a very lot worse with most users have many issues, but they are not. Just one in a hundred defect rate in each component would be at least one defect in each camera. So, defect rates in cameras as a whole (going past the sensor coating) maybe 1 in a thousand or more. Which is good.
Often people deceive themselves so much they do not understand, even when the truth is explained to them.
Offline

quickreactor

  • Posts: 4
  • Joined: Wed Nov 21, 2018 5:42 am
  • Real Name: Barnaby Fredric

Re: Pocket 4K - weak preamps?

PostSat Mar 23, 2019 2:20 am

pnguyen720 wrote:I'm glad I found this thread as I'm having the same issue running a Rode VMP.


Thank you for replying. The more people who share their experience the more chance something can be done about it. It seems like this is not uncommon and I think as more people get their cameras we will hear about it more.
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostSat Mar 23, 2019 2:25 am

I posted this in another related thread, but to inform as widely as possible, here is my inexpensive and effective solution to all the audio issues with the BMPCC4K: https://australianimage.com.au/blackmag ... -4k-pt-10/. The video at the end shows how it works.
https://australianimage.com.au/
Offline

pnguyen720

  • Posts: 84
  • Joined: Tue Mar 19, 2019 9:17 pm
  • Real Name: Phong Nguyen

Re: Pocket 4K - weak preamps?

PostSat Mar 23, 2019 4:31 am

Hi Ray,
Just to be clear, do you have your Rode plugged into that eBay recorder and you synch in post?
Offline

pnguyen720

  • Posts: 84
  • Joined: Tue Mar 19, 2019 9:17 pm
  • Real Name: Phong Nguyen

Re: Pocket 4K - weak preamps?

PostThu Apr 04, 2019 3:58 pm

Australian Image wrote:I posted this in another related thread, but to inform as widely as possible, here is my inexpensive and effective solution to all the audio issues with the BMPCC4K: https://australianimage.com.au/blackmag ... -4k-pt-10/. The video at the end shows how it works.


Hi Ray,
Just circling back.. are you just plugging into your audio recorder for sound now or are you still using the Pocket's 3.5mm input?
Offline
User avatar

Australian Image

  • Posts: 1503
  • Joined: Tue Oct 23, 2018 3:08 am
  • Real Name: Ray Pollanen

Re: Pocket 4K - weak preamps?

PostThu Apr 04, 2019 7:32 pm

pnguyen720 wrote:
Australian Image wrote:I posted this in another related thread, but to inform as widely as possible, here is my inexpensive and effective solution to all the audio issues with the BMPCC4K: https://australianimage.com.au/blackmag ... -4k-pt-10/. The video at the end shows how it works.


Hi Ray,
Just circling back.. are you just plugging into your audio recorder for sound now or are you still using the Pocket's 3.5mm input?


I'm using the Rode plugged straight into the audio recorder, no syncing in post. In fact because I also bought a Saramonic SR-M3 powered mic, thinking that was gong to be the answer (which it wasn't), I now use both the Saramonic and Rode (the Saramonic accepts a mic input) to provide some pretty awesome sound.

To all the old hands it sounds completely crazy and even idiotic, but it works. Sometimes you just have to try something crazy when nothing else seems to work. I have no idea why it works and whether it will work with more expensive voice recorders. I can tell you that my Olympus LS-14 sound recorder does not work.
https://australianimage.com.au/
Previous

Return to Cinematography

Who is online

Users browsing this forum: Csaba Nagy, mastrojm and 11 guests