We’ve looked at How to Choose and Use a Microphone with the Blackmagic Pocket Cinema Camera 4K, so in this article let’s take a look at how you properly configure the audio settings in the BMPCC’s audio menu.
How to Record Audio Using the BMPCC 4K
Menu > Audio
There are two screens to the Audio menu, the first is around input settings. The BMPCC 4K can accept two simultaneous audio sources, so you’ll see two channels with which to control those. Channel 1 and Channel 2 have exactly the same options.
Rather than go through the menu like a manual, we’ll stick to the same format as the Choose and Use a Microphone tutorial and look at the specific inputs and mics you’ll likely be using with those.
In the Audio menu, Camera Left and Camera Right refer to the inbuilt microphones, one on each side of the camera as you look at it with the lens facing away from you. You can have one mic set to record left and one right, both left or both right, or you can change them to Camera Mono which makes both microphones act as one, so a mono signal, rather than a stereo split.
Underneath the Channel Source options you can see the Level for each and can adjust that accordingly with the Gain sliders below.
The Levels are Digital Peak Programme Meters rather than VU (Volume Indicator) Meters. There are different types of PPM and they’ve changed over time, but the important part is that they make it easier to set your audio levels by displaying the peak volume (as the name would suggest), which is the highest it’ll reach, unlike VU which displays the average volume of the signal and so takes longer to sample. With PPM it’s quick and simple to see if you’ll hit levels that might distort. If you’d like to know more about the differences between VU and PPM audio meters, there’s a more in depth article on it at Shure.
Once you get past the settings for the inbuilt microphones, all the other options relate to either the 3.5mm Jack or the Mini-XLR inputs, and the various devices that can be plugged into those, so what you need to determine is which input best suits the kind of mic and feed you want to use – which hopefully you’ll have worked out by reading How to Choose and Use a Microphone.
We know the 3.5mm Jack doesn’t provide any power, so anything you plug into that has to be either something that doesn’t require power, or has its own power source.
You plug your mic into the 3.5mm jack and then in the Audio menu under Channel Source you’ve got three relevant options:
- 3.5mm Left – Mic
- 3.5mm Right – Mic
- 3.5mm Mono – Mic
You would select whichever mic level input is appropriate to the microphone you’re plugging in – probably mono. If you want a stereo split, you’d have to have the appropriate 3.5mm jack with split inputs going to a stereo microphone or two different microphones.
The key thing to remember is to select the version with Mic rather than Line, otherwise you won’t get anything. Line is for if you’re plugged into an audio source like a mixer or a PA system. Be wary to never put Line Level inputs into Mic Level settings. Although cameras are generally good at compensating for this now, it’s the equivalent of telling your camera you’re about to whisper and then you scream instead.
If you’re using an external audio recorder you might want to ensure – for synch reasons – that you have an output from that going into the camera, you can do that with the 3.5mm input but this time using the -Line option rather than -Mic.
Under Channel Source you have the same options with the Mini-XLR as you had with the 3.5mm Jack, but with the added ability to provide phantom power.
Options-wise you have XLR-Line and XLR-Mic, the former will let you select line level input and the latter is mic level input. As above, remember line is the higher voltage.
In practice, if you were using a Lav mic receiver you’d plug the receiver into the Mini-XLR with XLR-Mic selected in the menu, as the receiver outputs at Mic level, not Line level. In that scenario, as the transmitter and receiver packs have their own power, you’d need to make sure that Phantom Power is off in the camera. To do that, move across to the second menu screen under Audio and you’ll see an option with XLR Phantom Power that you can have either on or off.
If you were plugging a pro shotgun mic into the Mini-XLR input – one that requires phantom power – you would have the same settings as above but the mic is plugged directly into the Mini-XLR input and in the Audio menu, you’d need to turn Phantom Power on.
It’s good practice to always have Phantom Power OFF. If it’s off and required, it’s easy to switch on and no harm done. If it’s on and shouldn’t be, in the case of a mic already powered or that doesn’t need power, you can blow something by sending it unneeded power. Even if you know your mic requires the Phantom Power, it’s better to have it off first, plug in the mic and then switch it on rather than plugging it into pre-powered input.
For an unpowered mic (one that doesn’t require power at all, like one that might be on a camera for scratch audio or synching) you can plug into the Mini-XLR with XLR-Mic setting but make sure Phantom Power is OFF for the reasons just explained.
Other Audio Menu Options
Gain can be controlled in the Audio menu, but also by touching the PPM on the screen (bottom right) as you’re recording, which is probably the most sensible way to adjust it.
On the second Audio menu screen you’ll see two Audio Meter options:
- PPM (-20dBFS)
- PPM (-18dBFS)
PPM we know from earlier in the article is Peak Programme Meter and the dBFS is the decibel scale (decibels relative to full scale). 0dBFS is the maximum possible digital level so with -18 or -20 as in the options above, that means 18 or 20 dB below full scale. In Europe, the standard is -18 and in the US it’s -20 although there are countries that vary. Your camera will have come set to the standard for where you are, so you can leave it on that.
On the second Audio menu screen you’ll also see Headphone and Speaker volume. They’re pretty self-explanatory, though it’s worth knowing that when it comes to headphones, you’ll hear everything that’s plugged in, you can’t choose to only hear one channel or input. Essentially this means if you have a mic in the Mini-XLR and one in the 3.5mm Jack, you’ll hear one in one ear, and one in the other. This takes a bit of getting used to but it does make sense when you think about it, it’s wise to monitor all your audio sources.