BMCC Audio Performance - 1.2 vs 1.3 vs 1.4 vs 1.5

I worked with 1.4 and sound a bit today, using preamp on Juiced Link CX231. Ran camera input at about 33%, and CX231 on high setting and with Trim up pretty high too. I was able to get a pretty clean voice recording with my NTG 2 mic about 2 feet away. Background hiss was not an issue. I had not previously upgraded to 1.3, so I don't know if there is a difference.

whats the best way of "....sending a guide track and/or timecode to the BMC" ? (I have a Marantz PMD 661)

Sorry for the delayed reply John - I'm currently interstate on a job.

In general, I would send a line level guide track to the Left Channel of the Camera and a line level timecode signal to the Right Channel of the Camera.

In regards to the Marantz PMD 661 however - it's a prosumer device, so unfortunately it doesn't handle timecode at all. If you're mounting the 661 on the camera, then I'd just take the signal from the RCA outputs on the 661 and connect it directly to the camera (ensuring you have the right cabling - as you need to remember that the BMC has BALANCED inputs - otherwise you can run into phase cancellation issues). If you don't want to mount the 661 on the camera, then I'd just use a wireless transmitter/receiver to get the signal to the camera. You can then use something like PluralEyes, FCPX or Premiere CC to sync the camera's guide track to your 661 master audio.

Hope this helps!

Many thanks Chris!

Is V 1.4 doing the low end like 1.3? Or is it like 1.2?

I won't be able to test till Friday.

My test track is on this thread, so feel free to do the tests yourself.

My GUESS/HOPE is they have fixed the frequency attenutation issue. Fingers crossed!

I worked with 1.4 and sound a bit today, using preamp on Juiced Link CX231. Ran camera input at about 33%, and CX231 on high setting and with Trim up pretty high too. I was able to get a pretty clean voice recording with my NTG 2 mic about 2 feet away. Background hiss was not an issue. I had not previously upgraded to 1.3, so I don't know if there is a difference.

I'm sticking with 1.2.1. 1.3 for me broke audio recording on external mics, I think this problem only affected certain BMCCs. Nothing on 1.4 that I need but good to hear that there may be no audio issues any more (a part from lack of audio meters).

Jules

What's the latest word with recording audio into the BMCC. I've got firmware 1.4 and I remember reading that you can get it to work ok in v1.4 but can't find where I read the directions.

Unfortunately I haven't had time to do any tests with 1.4 as of yet.

Hopefully if I get time next week, I'll do some tests with 1.4 on both the BMCC EF and BMPC and post my findings here.

Judging from what I've read online, 1.4 doesn't seem to fix anything on the BMCC EF - but it does fix the frequency response issues on the BMPC - but I haven't done any testing personally to confirm or deny.

Just updated mine. just did a quick test with a signal recorded to h4 and the bmcc. imported the 2 files in nle and listened to both A/B, so this is not scientific but as far as i can say, in terms of Freqency Response nothing changed to FA 1.3, seems pretty much the same no lows.

Thomas

Unfortunately I've been caught up with shoots, but I have everything ready, and hope to do some proper tests either Tuesday night or Wednesday morning. Stay tuned!

I just recently received the BMCC cam, and am blown away by the quality of the RAW 2.5K image it produces. (sans aliasing, but hey, for $2K it's forgivable!)

Audio is super weird and non-workable, as everybody else said. Its behavior also varies widely per firmware version.

Original firmware the camera came with (I'm assuming v 1.3? How come BMCC does not display it?) produced tinny sound from Rode VideoMic Pro.

Upgraded to v1.4.1, current one at the moment - and seems like Line input went way down, plus i couldn't stand what they did with the supersensitivity of the touch screen monitor. It started to respond to the clicks that never there. Interface became unusable, had to revert to v 1.2.1 firmware (because I read 1.3 had audio issues worse than 1.2)

OK so with 1.2 installed, touchscreen UI is back to normal. But audio is still weird:

- Internal mic sensitivity is down. What required 25% slider with v1.4, now requires 60% slider with v1.2

- Still no luck with Line input. I tried two Tascams and a laptop as source of Line-level signal, and can barely hear it when Ch 1/2 are switched to Line, 100% amplification on BMCC, even with 100% output levels on those source devices. Recorded signal is proportionally low as well. WTF - Exactly how high should Line level input be to satisfy BMCC?

I read people use Sound Devices successfully with Line in at 85%. Is MixPre's line out so much higher than Tascams?

Also, the issue of connectors. Exactly which 1/4" plug should be used with BMCC?

At least I am able to record external mic now. Rode VideoMic at +20, connected to Ch 1 switched at Mic level, slider at 25%. Again, FW is v1.2.1 Sound seems passable at those settings.

But I am still spooked by the stories that the cam auto-switches to Line when Mic input is peaking, and that of course will produce a drop out in the recorded signal if true?

But I am still spooked by the stories that the cam auto-switches to Line when Mic input is peaking, and that of course will produce a drop out in the recorded signal if true?

This hasn't happened for me with firmware 1.2.1

Jules

Sorry for the delay - but I've finally done some quick tests comparing 1.3 and 1.4.

Sadly, as far as I can tell, nothing has changed in regards to audio between these firmware releases.

Results as follows:

Test Track:

01_test_track.png (535.68 KiB) Viewed 21052 times

1.3.1 Firmware:

02_bmc_1.3.1.png (564.03 KiB) Viewed 21052 times

1.4 Firmware:

03_bmc_1.4.png (562.79 KiB) Viewed 21052 times

1.4.1 Firmware:

04_bmc_1.4.1.png (551.04 KiB) Viewed 21052 times

Upgraded to v1.4.1, current one at the moment - and seems like Line input went way down, plus i couldn't stand what they did with the supersensitivity of the touch screen monitor. It started to respond to the clicks that never there. Interface became unusable, had to revert to v 1.2.1 firmware (because I read 1.3 had audio issues worse than 1.2)

Not sure what was happening for you. As far as I can tell 1.4 performs exactly the same as 1.3.

As far as I know, you're the first person to report touch screen glitches as well.

Remember, the BMC has BALANCED audio inputs. A lot of people mistake low levels with phase cancellation problems.

Check your cabling. As you can see in this thread, I have been able to get good LEVELS (ignoring DC offset, frequency attenuation, and all the other horrible firmware issues, etc.) from external microphones using all versions of the firmware - it's just that the level SCALE changes in different firmware releases (i.e. 100% line level means something different in 1.2 than it does in 1.3 - but the performance of the pre-amp is the same, you just need to compensate). If you're happy to do some magic in post - then you can still get USEABLE results using a self-powered microphone plugged directly into the camera.

So, how much need is there for balanced output to the BMCC from a PreAMP like the JuicedLink Riggy micro into the camera or into a recorder, they're gonna be close, no long cable lenghts.

I'm looking to go from an external solution like the h4n (which has pretty lousy preamps) to go straight into the camera with a preamp.

So, how much need is there for balanced output to the BMCC from a PreAMP like the JuicedLink Riggy micro into the camera or into a recorder, they're gonna be close, no long cable lenghts.

The juicedLink Riggy Micro doesn't actually have balanced outputs - it has an amplified mic level output via a 3.5mm stereo mini-jack. The juicedLink BMC366 Blackmagic Cinema Camera Preamp however has 2 balanced 3.5mm locking minijack outputs at amplified mic level.

Earlier in this thread Robert from juicedLink explained his reasoning behind why he went with mic-level as opposed to line-level for his Riggy devices.

Balanced cabling is really only useful for long cable runs. If you only have a 10cm cable run - then running unbalanced will be fine as the chance of noise being introduced into the cabling is minimal.

I'm looking to go from an external solution like the h4n (which has pretty lousy preamps) to go straight into the camera with a preamp.

This is definitely an option - HOWEVER, if you're going to be using the external audio anyway and sync in post - then I wouldn't even both with the pre-amp, as you'll just be using this as a guide track.

Adding a pre-amp to the BMC is only really useful if you plan to use the camera for your final audio. With the current firmware, using the audio straight off the camera has major limitations (frequency attenuation issues, it's very hard to monitor the headphone jack, etc.) - but you can't fix majority of the issues in post. Will the final audio sound as good as a professional (or even prosumer) external recorder? No. But depending on what you're filming, you may be able to get away with it.

I'd want a preamp to always be on the rig, would you say that if it goes beyond 10cm, unbalanced becomes an issue.

The long end would be on the input side, which I suppose is balanced because it is XLR ?

I saw the bmc366, but it seems rather bulky, really looking for a smaller solution. And from what I've read, the recorders that do have decent pre amps are yet to become affordable for me.

About the Bmcc internal sound, yeah I've read the threads, it does however look as the ideal solution if it ever gets fixed, for my intents and purposes.

Sent from my Android Phone

would you say that if it goes beyond 10cm, unbalanced becomes an issue.

Balanced cable is really only necessary for long cable runs (i.e. if you have a boom microphone connected directly to the camera). If you're just using the cable to connect a pre-amp that's on the camera rig itself, the chance of noise being introduced into the cabling is minimal.

The long end would be on the input side, which I suppose is balanced because it is XLR ?

XLR cables are balanced - however, balanced cabling only works if both the input and output are balanced. If you connect an unbalanced signal into the BMC for instance, the whole wiring is considered unbalanced.

I saw the bmc366, but it seems rather bulky, really looking for a smaller solution.

The BMC366 is pretty compact, and weighs only 8 oz - I'd hardly call it bulky.

XLR cables are balanced - however, balanced cabling only works if both the input and output are balanced. If you connect an unbalanced signal into the BMC for instance, the whole wiring is considered unbalanced.

So even if it's balanced cabling up untill the bmcc366.

The unbalanced output of it would introduce the possibility of noise happening to the balanced XLR cabling on the input side of the preamp. Correct?

By the way, I appreciate you taking the time to answer my questions, I'm learning lots!

So even if it's balanced cabling up untill the bmcc366.

The BMCC has Balanced inputs. The BMC366 has Balanced outputs. Therefore the connection between the camera and pre-amp is balanced to help ensure no noise is introduced into the cabling.

The juicedLink Riggy Micro however has Unbalanced outputs, and therefore the connection between the camera and the pre-amp is unbalanced.

This video might be of some help explaining the differences:

http://www.juicedlink.com/xlr-balanced- ... unbalanced

So as long as i keep the riggy with unbalanced output close to the camera it won't be a problem?

But I am still spooked by the stories that the cam auto-switches to Line when Mic input is peaking, and that of course will produce a drop out in the recorded signal if true?

This hasn't happened for me with firmware 1.2.1

Jules

It just happened to me a day ago. I was feeding Rode VideoMic Pro into BMCC, all was well for about 2 min, then the recorded volume just dropped tremendously - I assume this is because of the internal auto-switching to Line level in BMCC. Mic batery was fine, connections were fine...

So as long as i keep the riggy with unbalanced output close to the camera it won't be a problem?

Yes - every Riggy user (with the exception of those with the newly released BMC366) are running unbalanced cables from their preamp to camera (normally because most are using the Riggy products with DLSRs that only have unbalanced inputs anyway). You'll be fine.

It just happened to me a day ago. I was feeding Rode VideoMic Pro into BMCC, all was well for about 2 min, then the recorded volume just dropped tremendously - I assume this is because of the internal auto-switching to Line level in BMCC. Mic batery was fine, connections were fine...

Yes - this is the main reason I'm running the latest firmware on the camera. It's a matter of choosing compromises. Personally, I'd prefer to have to EQ the audio (which is still a pain), than have to deal with the DC Offset and the risk of the camera automatically switching from Mic Level to Line Level, or from Line Level to completely off (which has also happened to me a couple of times - mainly when I disconnect and reconnect the audio snake).

The Tascam DR-60D recorder looks like a solution, especially for the pocket camera.

this is the main reason I'm running the latest firmware on the camera. It's a matter of choosing compromises. Personally, I'd prefer to have to EQ the audio (which is still a pain), than have to deal with the DC Offset and the risk of the camera automatically switching from Mic Level to Line Level

Do I understand correctly that FW 1.4.1 **no longer** auto-switches Ch1 Input from Mic to Line, like v 1.2 did?

Do I understand correctly that FW 1.4.1 **no longer** auto-switches Ch1 Input from Mic to Line, like v 1.2 did?

Yes, this "feature" was removed in 1.3. I haven't done much testing with 1.4, but I haven't noticed any issues yet - as far as I can tell none of the audio features have changed between 1.3 and 1.4.1.

this is the main reason I'm running the latest firmware on the camera. It's a matter of choosing compromises. Personally, I'd prefer to have to EQ the audio (which is still a pain), than have to deal with the DC Offset and the risk of the camera automatically switching from Mic Level to Line Level

Do I understand correctly that FW 1.4.1 **no longer** auto-switches Ch1 Input from Mic to Line, like v 1.2 did?

Firmware 1.2.1 doesn't auto-switch as I spent three hours recording not realising that the input was way too hot (no audio meters... darn it!). Had to do some post-processing to recover some of the clipping, not one clip had this auto-switch happening.

Jules

Firmware 1.2.1 doesn't auto-switch as I spent three hours recording not realising that the input was way too hot (no audio meters... darn it!). Had to do some post-processing to recover some of the clipping, not one clip had this auto-switch happening.

This is not what our testing has found. Robert from juicedLink also had the same results.

Firmware 1.2.1 doesn't auto-switch as I spent three hours recording not realising that the input was way too hot (no audio meters... darn it!). Had to do some post-processing to recover some of the clipping, not one clip had this auto-switch happening.

This is not what our testing has found. Robert from juicedLink also had the same results.

That might be the difference between firmware v1.2 vs 1.2.1?

Jules

Jules, 1.2.1 here and it auto-switched alright.

Jules, 1.2.1 here and it auto-switched alright.

Since mine doesn;t auto-switch, it's not an issue for me. I can't upgrade firmware anyway as I'd have to buy an active pre-amp and I'd rather avoid the expense.

Chris said something about the 'scaling'. Not sure what he means, but either way if I used firmware 1.3 or greater, I can't hear anything in my headphones. I'm hoping BMD fixes the camera's pre-amp problem and make it so at least with a passive adaptor or direct connection a low impedance mic is audible in the headphones.

Jules

Right now I think BMCC's audio is only usable as a scratch track. On the last job I simply used built-in mic, because I don't feel it's reasonable to build up an external preamp for this camera since I don't trust its audio capabilities anyway.

I always shoot multicam, or at least double system, so the proper sound is being recorded elsewhere.

On top of it, I just ran into the AV sync issues!

viewtopic.php?f=2&t=4318&p=78309#p78285

On top of it, I just ran into the AV sync issues!

We've done a LOT of long interviews, and haven't experienced this issue yet. We shoot everything at 25fps in ProRes though.

I've just did some audio tests with my BMCC Firmware 1.3 and my Sound Devices MixPre-D.

If i set my BMCC to "Line 100%" and send in the 1khz 0db tone from the MixPre-D i get a Level of -35db in Premiere. Am i wrong or shouldn't this be around -20db regarding the tests in this thread?

I've got my BMCC on FW 1.4.2 along with a SD Mixpre-D and I'll be running a Sennhesier G3 wireless mic set.
I'm still a little confused... What is the recommended settings on the BMCC (and ideally the Mixpre-D) to get the best in camera sound?

Hey guys,

I just received a bmpcc this week and was hoping to run some audio tests...but I'm not really sure what I should be testing and how. If someone's willing to give me some guidance of what to test, I'd love to run those tests as a reference (and as a learning experience for me).

In addition to the bmpcc I have:

Zoom h1, h6 and Sony PCM-d50. Also a zoom r16.
Sennheiser me64, me66, k6 (the one with the battery power plus phantom)
Sennheiser g3 ew100 wireless lav kit
Panasonic gh2 and sescom cable
Couple of giant squid lavs
An old juicedlink (pre-dslr, have to find it to lookup model number).
Lots of wires to connect everything.

Many thanks for the info in this post, specially that provided by Chris Hocking. However, I still don't quite get it. After updating from 1.2 to 1.4 (we never used 1.3), the audio recording is just TOO LOW (in regular interviews, between -30 and -18 dB, or even lower) in the following conditions:

- Boom connected directly to the camera
- Channel 1 input at 100%
- Channel 2 using channel 1 input

Before, we recorded with channel 1 input at 50%, and got a reasonable level (between -12 and -6 dB), all conditions being the same (microphone, cable, etc.). Why all of a sudden this dramatic level drop? Certainly one can do some improvements in post, but:

1. These improvements are time-consuming, and
2. Many times they involve a higher background noise

BCC 2.5K is intended to record sound without the traditional extra equipments required by DSRL cameras, so this is just a bug, and as such it should be fixed soon. I would recommend to write to Blackmagic Support insisting on a solution.

We've just tested the 1.5 firmware release on the BMCC EF, and as far as we can tell, absolutely nothing has changed from 1.3 to 1.5 in terms of audio performance. Better luck next time!

1.5.png (455.35 KiB) Viewed 18428 times

Thanks Chris !

Chris H, thanks for this post and testing. It has been over 6 months, yet no BMCC firmware update related to this problem. I trust the said firmware update that is coming, hopefully soon, will solve the problems. I am questioning if I should purchase a Sound Devices MixPre-D, given the issues raised in the other current thread...

Up the thread!
I'll have the same question others have had here, can I use BMCC as a quality recorder when using MixPre-D?

I'd really really appreciate newest firmware test, please.

Thanks, K

I am going to be shooting Sunday evening, and I am going to record dual system but feed the signal to the camera too to see if single system is workable. Meters are still needed, but hopefully this will tell me if the camera is now up to it after 1.8