"It's got four microphones."

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Jim Simon

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"It's got four microphones."

PostSun Apr 15, 2018 10:28 pm

Where? And why? No one talking about the Pocket 4K ever says.
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James Westlake

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Re: "It's got four microphones."

PostSun Apr 15, 2018 11:16 pm

My guess is that two might be used to subtract the sound of the internal fan from the other two, perhaps? Because otherwise I don't see a lot of point in four mics being used to capture 2 channel stereo audio, unless I'm missing something?
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Jim Simon

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Re: "It's got four microphones."

PostTue Apr 17, 2018 10:22 pm

James Westlake wrote:unless I'm missing something?


I think we all are. BMD never say anything beyond "It has four."
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Chris Chiasson

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Re: "It's got four microphones."

PostWed Apr 18, 2018 1:36 am

I think Grant really wants to make a camera that records usable audio internally, and kill the requirement for an external mic. I applaud him for it, but I doubt it’s possible, unless you go the “mic on the handle” route doc cameras used. As is, the mics are in the position where hands focusing the camera is gonna be recorded,with fingers taping the mic when operating handheld. I only see these being usable for recording stereo audio for exterior landscapes, or establishing wide angles.
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Jeremy Dallek

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Re: "It's got four microphones."

PostWed Apr 18, 2018 2:04 am

I think the noise reduction theory sounds logical. The question I have is how many of the 5 audio sources in the camera (Internal Mic L, R, 3.5mm L, R, Mini xlr) can be recorded simultaneously? Only 2? I remember seeing a video where it looked like only 2 assignable audio record inputs, but it would be really nice to have all of them available.
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Steve Golding

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Re: "It's got four microphones."

PostWed Apr 18, 2018 9:41 am

I'm fairly sure that two are used in some form of 'Noise Canceling' system to remove the fan or other internal noise.

Steve
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Jim Simon

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Re: "It's got four microphones."

PostMon Jun 18, 2018 4:21 pm

So...can someone from BMD please state the facts here?
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Brad Hurley

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Re: "It's got four microphones."

PostMon Jun 18, 2018 4:34 pm

There is little point of using any on-camera mic (either built-in or mounted) for anything but reference tracks for syncing or run-and-gun situations where audio quality isn't important. The mics are too far from the sound source (certainly for dialog, perhaps not for ambient sound). I use the internal mics for reference tracks; occasionally I can salvage something (with a lot of post-processing) for background sound. I think if you ask any location sound person for the most important advice on getting good sound, it would be "get the mic off the camera!"

They could put 26 mics on this camera and it still wouldn't get me excited.
Last edited by Brad Hurley on Mon Jun 18, 2018 4:37 pm, edited 1 time in total.
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Denny Smith

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Re: "It's got four microphones."

PostMon Jun 18, 2018 4:36 pm

All the other BM cameras on,y record two audio tracks, so I do not expect the new Pocket 4K to be any different. The four mics could also be assigned two per channel (L/R) with the two mic capsules adding more or a better balance audio range, and improving the Zsingal to noise ratios. I heard the audio track on one of the demo NAB cameras, and it was the best sounding audio for a built in mic that I have heard so far. The camera was recording a music group performing.
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Brad Hurley

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Re: "It's got four microphones."

PostMon Jun 18, 2018 6:21 pm

Denny Smith wrote: I heard the audio track on one of the demo NAB cameras, and it was the best sounding audio for a built in mic that I have heard so far.


That's encouraging, but still sounds like faint praise..."for a built-in mic."

I have no doubt that these will be way better than the mics on the original pocket, but there's no getting around the laws of physics: each time you double the distance from a sound source, its sound pressure drops by 6 decibels. And the farther you get from a sound source, the more influence you get from reflective surfaces and ambient noise. So while it's possible to get usable sound from a camera mic (e.g., if you're filming an interview from 4 feet away or an amplified concert), I still think it's important to understand the limitations of in-built or camera-mounted mics and adjust expectations accordingly. It's fine for some purposes but people who buy the Pocket camera thinking they'll never need to bother with an external mic will probably be disappointed.
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Denny Smith

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Re: "It's got four microphones."

PostMon Jun 18, 2018 6:26 pm

Yes, I agree, the built in mics May be very good, but only useful for ambient sound or a close in interview or blogger situation. Yiu are still going to need an external mic for normal work. That is why they include a balanced pro mic level input via the Mini XLR connector.
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John Morris

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Re: "It's got four microphones."

PostTue Jun 19, 2018 2:48 am

Although its not spelt out if you can record the 4 inbuilt mics on more than one individual track, it sounds like the 4K will be able to record to more than 2 tacks:
https://forum.blackmagicdesign.com/viewtopic.php?f=2&t=72674#p404982
But but I can't see that in the URSA Broadcast manual. I would expect to be able to at least mix the inbuilt mics to stereo as the old BMPCC can. Multichannel recording would be a nice feature though, if I interpret that post correctly.
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Denny Smith

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Re: "It's got four microphones."

PostTue Jun 19, 2018 5:12 am

John, yes and no, youn are still limited to two recorded audio tracks, and one T/C track (via thr 1/8-inch audio input for LTC time code.

According to the reference you gave, the internal mics can be mixed in track 1, and thr XLR mic input recorded on So you still only have two recorded tracks. With the LTC recorded as a T/C track separate from the two audio tracks, which is nice. Previously, LTC would have used up one of the two audio tracks.

This is how thr Ursa Boradcast handles its audio inputs, see thr Ursa Broadcast manual for details.
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Last edited by Denny Smith on Tue Jun 19, 2018 6:36 pm, edited 1 time in total.
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Jim Simon

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Re: "It's got four microphones."

PostTue Jun 19, 2018 6:06 pm

Brad Hurley wrote:perhaps not for ambient sound


Which is how I use them for event work. The original Pocket's built-in mics were unusable even for this. I'm desperately hoping this has been resolved in the Pocket 4K.

But I still would like an official explanation for why four mics.
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Jim Simon

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Re: "It's got four microphones."

PostTue Jun 19, 2018 6:08 pm

Brad Hurley wrote:I still think it's important to understand the limitations of in-built or camera-mounted mics


The Rode Stereo VideoMic Pro works perfectly for my needs, except that it takes up the top shoe mount making adding a camera light...difficult.
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Denny Smith

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Re: "It's got four microphones."

PostTue Jun 19, 2018 6:42 pm

Jim, Actually, it should be fine for ambient sound recording. Elton John used the built in mics on the Micro Studio camweas he had placed for IMag during his concert tour last year, and mixed the camera mics audio in for ambient audio. The new Picker 4K should be even better than the very good Micro Studio mics.
Each camera BM makes has a jump up in audio quality. :mrgreen:
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Jim Simon

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Re: "It's got four microphones."

PostTue Jun 19, 2018 11:23 pm

Thanks, Denny. That's good to know.

But it's also...tangential.

I'm still wanting to know why there are four microphones on the Pocket 4K.
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Denny Smith

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Re: "It's got four microphones."

PostWed Jun 20, 2018 1:48 am

Good question :?:
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Jim Simon

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Re: "It's got four microphones."

PostMon Jul 09, 2018 10:20 pm

C'mon, someone from BMD must know the answer to this.
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David Peterson

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Re: "It's got four microphones."

PostTue Jul 17, 2018 8:00 am

Would be lovely if more cameras supported multi track recorder of external audio AND internal mics at once.

Then you could for instance send a wireless camera hop into the camera, and not worry about the risk of if batteries die or gets an RF hit as you will have the internal scratch audio for sync as a back up
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Jim Simon

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Re: "It's got four microphones."

PostFri Jul 27, 2018 3:49 pm

David Peterson wrote:Would be lovely if more cameras supported multi track recorder of external audio AND internal mics at once.


I would find that useful as well. I could send a board feed wirelessly to the external inputs, and use the built-in mics for nat sound. Would definitely make my editing simpler.
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rick.lang

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Re: "It's got four microphones."

PostTue Jul 31, 2018 4:15 am

Has anyone else noticed the schematic diagram for the BMPCC4K has two arrows pointing to the left and right area microphones but the label says Dual Microphones? Interesting that no one from BMD wants to explain why there are four microphones. I’ll bet there’s a very good reason for that. Imagine if someone had posted the recipe for Coco-Cola before it even went into production?
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Brad Hurley

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Re:

PostMon Aug 13, 2018 8:04 pm

rick.lang wrote:Has anyone else noticed the schematic diagram for the BMPCC4K has two arrows pointing to the left and right area microphones but the label says Dual Microphones? Interesting that no one from BMD wants to explain why there are four microphones. I’ll bet there’s a very good reason for that. Imagine if someone had posted the recipe for Coco-Cola before it even went into production?


I was looking at this too: https://www.blackmagicdesign.com/produc ... s/W-CIN-12

It only says "Dual microphones" and the spec says "stereo microphones."

What I am guessing is that it doesn't have four microphones but rather it can record input from up to four microphones. You have the two built-in mics, which record in stereo, plus you have a mini-jack microphone input (same as on the old Pocket camera), plus you have the mini-XLR input. That's four, but not four built-in mics.
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Denny Smith

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Re: "It's got four microphones."

PostMon Aug 13, 2018 8:30 pm

Actually that is five, if you use a stereo mic in the Mini plug input or use an external mixer like the PixPre D which has a 1/8 Mini stereo line out. Another explanation is there are two mic cartridges under each side mic cover, to get a wider audio dynamic range, or wider area coverage, so technically four mics, but two audio channels.

As for recording four channels in camera, not sure they did this. The Ursa Broadcast has four mic inputs, if you count using the two XLR inputs as AES digital inputs, each XLR could carry two channels, or two external mic inputs and two built in mics. It has a four channel option, but currently can only record two channels. :cry:
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Jim Simon

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Re: Re:

PostMon Aug 13, 2018 9:20 pm

Brad Hurley wrote:What I am guessing is that it doesn't have four microphones but rather it can record input from up to four microphones.


While that would be useful, I have reason to believe it can't actually record four channels at a time.

And there's a video of Grant specifically saying it has "four microphones", pointing to the built-in mics when he says it. But no one from BMD has yet said why it has four, which is not a common design and I believe deserves explanation.
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Denny Smith

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Re: "It's got four microphones."

PostMon Aug 13, 2018 9:46 pm

Yes, yes it does... (require an explanation thst is)
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michaeldhead

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Re: "It's got four microphones."

PostMon Aug 13, 2018 10:20 pm

Maybe I'm the only one, but does it really matter why? At the NAB announcement, Grant said it had four mics when he was talking about using it as a vlogging camera (which I still find odd). So better pickup from the front of the camera.

But I'm usually going to run either dual-system audio or straight into the XLR input - am I the only one planning on recording audio that way? I might map the internal mics to one channel just to have the safety track, but for the most part I'm never relying on camera audio for a project (and the one time I did due to a recording problem, it didn't turn out good).
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Brad Hurley

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Re: "It's got four microphones."

PostMon Aug 13, 2018 10:46 pm

michaeldhead wrote:But I'm usually going to run either dual-system audio or straight into the XLR input - am I the only one planning on recording audio that way? I might map the internal mics to one channel just to have the safety track, but for the most part I'm never relying on camera audio for a project (and the one time I did due to a recording problem, it didn't turn out good).


If you look up in this thread, you'll see that the original poster uses built-in camera mics for ambient sound, and it would also be a good simple choice for vbloggers.

Like you I do dual system, but I have on occasion salvaged usable sound from recordings made with my first-generation Pocket Cinema camera mics.

As for what these four mics do and why there are four, I guess we just have to wait and see. Could be something cool like what Soundfield does with their four-mic ambient sound units, or could be much more prosaic. We should know in a month or so, although I agree it's odd that they haven't emphasized this in any of their advertising, which makes you wonder whether the final camera will actually have four mics after all. It would be a feature worth advertising, but they've not said anything about it in print or in the camera specs.
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Jim Simon

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Re: "It's got four microphones."

PostTue Aug 14, 2018 3:44 am

michaeldhead wrote:Maybe I'm the only one, but does it really matter why?


We won't know if it matters until we know why?
Last edited by Jim Simon on Wed Aug 15, 2018 3:28 pm, edited 1 time in total.
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michaeldhead

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Re: "It's got four microphones."

PostTue Aug 14, 2018 2:07 pm

Brad Hurley wrote:We should know in a month or so, although I agree it's odd that they haven't emphasized this in any of their advertising, which makes you wonder whether the final camera will actually have four mics after all. It would be a feature worth advertising, but they've not said anything about it in print or in the camera specs.


They do advertise it as a feature - it's on the "Design" page of the Pocket overview: https://www.blackmagicdesign.com/produc ... era/design
And Grant Petty pointed it out at the NAB announcement when he was pointing out the "vlogging" features (which still strikes me as weird).

I imagine that they are using four mics because so many of the reviews of the original Pocket talked about how terrible the in-camera sound was (is), but that gets back to the designation as a "cinema" camera - when shooting for "cinema", you typically record sound separately.

Even ambient sounds are typically recorded on the external recorder - if you want to make people start to giggle or cough, just start rolling room tone :)

I have had a project "saved" by in-camera audio (there's a whole story with that) but it sounded terrible compared to when the dual-system audio was working (operator error - like I said, there's a story).
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Denny Smith

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Re: "It's got four microphones."

PostTue Aug 14, 2018 5:11 pm

The BM illustration shows what looks more like a dual capsule mic, rather than four separate mics, but hard to tell from one artistic rendering, we know can be somewhat inaccurate... :roll:
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