Headphone Performance on BMC

Chris, what do you mean by "noisy" headphones? Are you getting static or popping or stuff like that in your headphone output? Mine's pretty much clean...and LOUD. I was pretty surprised at how loud the headphone output was...especially since the audio recording level was so low. (1.2)

With nothing else connected to the camera, if I plug in a set of good quality headphones, and set the headphone volume on the camera to 0% I can still hear "white noise". It's not horrible, as the volume of the noise is very low - but it's very distracting. With nothing else connected, when I adjust the headphone volume from 0% to 100% the noise level doesn't change. This happens regardless of whether I have Line or Mic selected, and what levels I have Input 1 and 2 set as. This tells me that either the audio circuitry is bad, or there's something in the firmware that's producing this noise (i.e. digital gain). In comparison, if I plug the same headphones into my MacBook Pro or my Sound Devices 302, I don't get this same noise issue - so it's not a problem with the headphones.

However, the real annoyance comes with plugging in any inputs into the camera. For example, with nothing else connected to the camera, I set the headphone volume to 70%. As explained, I can hear noise in the headphones, but it's not horrible. As soon as I plug in something into Input 1, the noise increases. You can hear the pre-amp "pop" into gear, and you can basically hear the camera "think". In this case I'm plugging in my Sound Devices 302 which is turned off, so really, plugging this in should do nothing. I know the cabling isn't the issue, because if I plug the 302 into a 552, Sound Devices PIX, etc. I'm not hearing the same issues.

If I unplug the cable from Input 1 and put it into Input 2, you get the same result. The pre-amp "pops" into gear, and you can hear the camera "thinking" - but this time it's obviously more biased to the right headphone. That said - as soon as you plug in a cable to a SINGLE input on the camera, the noise level increases on BOTH left and right - however additional noise gets added to whichever input you plugged into (i.e. if I plug in a cable to Input 1, the overall noise will increase, but there will also be added noise to the left channel).

What really sucks though is if I plug in both inputs. With the headphones set to 70%, with nothing connected, the white noise is there. With a balanced line-level signal connected to Input 1, the overall white noise increases, but there is also more noise on the left than the right. With a balanced line-level signal connected to Input 2 as well - the overall white noise increases again.

Let me give you an example. I have a 302 connected to a BMC running 1.3.1. I'm using XLR to balanced Jack cables - and everything is wired corrected. All the inputs on the 302 are at 0%, and when I monitor the output signal on the 302, it's basically dead quiet - so the 302 is effectively outputting "silence". On the camera I have Microphone Input set to 0%, Ch 1 and Ch 2 Input Levels set to Line and Ch 1 and Ch 2 inputs set to 100%.

This is what I'm hearing in the headphones connected directly to the BMC:

Headphone Volume 0%: Very soft white noise, that seems to slowly pan between the left and right channels.
Headphone Volume 20%: The noise pulses between the left and right channels quite quickly (kind of like a metronome).
Headphone Volume 50%: The noise pulses between the left and right channels, however it seems to be at a different frequency than at 20%.
Headphone Volume 100%: The noise levels are so loud that you can't hear the pulsing any more. As far as my ears can tell, there is similar white noise between the left and right channels - so you can't tell any difference between the two.

Given the pulsing sound - obviously I'm wondering if the camera's fan is the reason for the noise. It would make sense. But the main thing I want to work out is... is this just my camera, or do all cameras have the same issue?

This isn't a massive issue for me - as what I currently do is monitor all the audio off the 302, and just every now and then flick over to the return to make sure the camera is still getting a signal. This works fine, I just need to always remember to double check the return before and after each take to make sure nothing has gone wrong. I'd love to be able to just monitor the return feed the whole time (like I do when recording to an Alexa or Sound Devices PIX), but the BMC headphone output is simply too noisy at the moment.

When I get a chance, I'll check out some other BMC's at local hiring companies but until then...

Is anyone else hearing the same thing?

I use the headphone plug of my monitor (TVLogic), that feeds from the SDI connector of the BMC - much better.

I use the headphone plug of my monitor (TVLogic), that feeds from the SDI connector of the BMC - much better.

So, can I assume then that you're noticing the same issues with the headphone jack on your camera?

Yeah, the Headphone out of the BMC is not exactly HiFi. I was often surprised, how much better the actual recording sounds. But on the other hand, for me it's just a rough control, the actual evaluation on set during recording, is done by my sound guy with headphones on his mixer..

But on the other hand, for me it's just a rough control, the actual evaluation on set during recording, is done by my sound guy with headphones on his mixer..

If you're recording audio separately, then obviously this isn't an issue at all. However, if you're wanting to record useable audio directly to the camera (which a lot of people will want to do for the huge time and cost saving benefits) - then having a really noisy headphone jack is really frustrating.

As I said, currently I have a 302 hooked directly to the BMC, and I just monitor off the 302, and occasionally switch over to the return feed to make sure the camera is still "hearing things" properly. This is a workable solution - but it's really not ideal. If the camera operator accidentally disconnects the audio snake cable, then I potentially loose a take - which could be very painful if you're shooting documentary style.

For most jobs, we'll do dual system - and record the audio completely separately to camera (but have everything timecode synced). But for jobs that are time and money constraint, then having the ability to record audio directly to camera, and end up with ProRes files with sync sound is a huge bonus. This workflow is absolutely perfect with the Alexa - with my ears, I can't actually hear the difference between the audio I'm getting off the Alexa versus a 744T or 552. I just wish I could say the same for the BMC.

In terms of the image quality, in a lot of cases the BMC makes a perfect B or C camera to the Alexa. In terms of audio quality - sadly, the Alexa is in another league.

Hopefully though... this can be fixed with firmware updates. But if it can't - I just really hope they've improved the audio hardware in the upcoming 4K camera.

Hopefully though... this can be fixed with firmware updates. But if it can't - I just really hope they've improved the audio hardware in the upcoming 4K camera.

I really hope they at least improve the audio in the upcoming Pocket CC!

For the larger CCs external audio recording is more likely, but the Pocket CC loses a lot of its "run, gun & fun" charme when you can't get usuable audio in-camera.

If you're recording audio separately, then obviously this isn't an issue at all. However, if you're wanting to record useable audio directly to the camera (which a lot of people will want to do for the huge time and cost saving benefits) - then having a really noisy headphone jack is really frustrating.

No, no, no - I always record in camera, whenever possible, since I think that external recording in an utter waste of time.

What I wanted to say is, that my boom guy is riding the levels on his field mixer (and got his headphones plugged in in the mixer) but from there it goes directly to the camera. I listen to the headphone out of the camera or SDI offboard monitor, just to make sure everything is there, so I don't really need a stellar sound quality.

For the larger CCs external audio recording is more likely, but the Pocket CC loses a lot of its "run, gun & fun" charme when you can't get usuable audio in-camera.

I think there is a sheer physical conflict between the terms

1. "pocket size",
2. "run, gun & fun"
3. "usable audio".

I think you can only pick two at a time.

Having a mini mic build in a pocket size camera gives you handling noise and too much distance. Also it picks up the noise of the lens IS if you use it .

Having a normal shotgun on the camera doesn't make it pocket size anymore and you are still too far away - at least for proper dialog, for general ambiance this would work, but you still have a small camera with a huge shotgun rigged in a suspension and some other hardware - not exactly pocket size.

Having a boom guy hooked to the pocket sized camera, does contradict the whole pocket size run and gun fun thing.

What I wanted to say is, that my boom guy is riding the levels on his field mixer (and got his headphones plugged in in the mixer) but from there it goes directly to the camera. I listen to the headphone out of the camera or SDI offboard monitor, just to make sure everything is there, so I don't really need a stellar sound quality.

And this is the problem... if there is a hum or added noise in the cable between the mixer and the camera, you have no way to know, as the headphone output is so noisy.

I'm currently doing things exactly the same way as you - and it works. Most of the time it's fine.

But... it would be MUCH better if I could monitor what's ACTUALLY being recorded on the camera.

Surely accurate headphone monitoring isn't too much to ask for?

For anyone who's interested, I got a response from BMD earlier in the week regarding this issue. They didn't really comment on the performance - but they noted that they are investigating the issue. I'll let you know if I hear anything further.

I'm also experiencing a high-frequency hiss coming through my headphone jack on the BMPCC. The mic I'm using is part of the Sennheiser ew-g3 transmitter/receiver combo, and when I record a clip the audio is perfect and clean in the recorded file.

In other words, the high-frequency hiss appears to only come through the headphone jack (whether monitoring/recording or playing back in camera), and isn't being recorded to the file.

This sounds like a messed up headphone jack to me. Anyone else experience this?

The discouraging part is that I AM using an external mic, and it's working great, but the noise makes it extremely difficult to monitor audio.

I have tested several pairs of headphones, ranging from high-end studio Shure headphones to cheap earbuds. They all exhibit the same problem.

Yep - the headphone preamps are incredibly noisy. I just monitor our external mixer and switch over to the return feed at the start and end of each take for confidence checks. If I was stuck just listening to the headphone output on the camera my head would explode!