BMPCC4K – Audio Issues

Finally I’m having some success. As I pointed out in Part 6, as a last desperate measure I’d ordered an inexpensive powered Saramonic SR-M3 directional microphone (shotgun mic) to see if that would alleviate my need for the Olympus LS-14 audio recorder. It arrived and I have to say that I was apprehensive given that there was so little information available with regards to this microphone when it came to use with the BMPCC4K. Actually, I couldn’t find anything informative. Every review was about it’s use with a DSLR or mirrorless camera for vlogging purposes, something that wasn’t going to be its intended use. I wanted to use it as a field microphone for general use on my rig, which may not have been ideal, but that’s what I needed.  As an aside, for once a product was available locally at considerably cheaper price than anything available overseas. I never cease to wonder at these price variations. There are plenty of general reviews of the Saramonic, so I’m not going to do a general review but will go straight into testing

Saramonic SR-M3 Shotgun Microphone - (source: Saramonic)

Saramonic SR-M3 Shotgun Microphone – (source: Saramonic)

Saramonic SR-M3 Shotgun Microphone Specifications

Saramonic SR-M3 Shotgun Microphone Specifications

My first test was to connect it to the camera on its own and then via the Cayin C5 amplifier. I think I was holding my breath on the first test and exhaled loudly when the audio meters on the camera registered the audio input. I then connected it to the Cayin and repeated the test and once again, the meters registered and so finally it looked like all was going to be good. When I connected the Rode VideoMicro to the Saramonic, it too worked, so I ostensibly had two microphones providing audio input to the camera. From some of the reviews that I watched, apparently the Saramonic will combine the input from its own microphone and that of an external one into a single signal (it’s not mentioned on the Saramonic site how it works). A useful option that this can give you is that it allows additional audio from other directions to be included in the recording. If you’re recording activities happening in front of you, you can attach a Lav microphone and record additional voice over to the audio recording, or you can attach a hand held microphone for reporter-style audio recording. All potentially useful, if for no other reason than having the combined audio as a backup to other recording devices.

Saramonic SR-M3 Shotgun Microphone - Original Configuration

Saramonic SR-M3 Shotgun Microphone – Original Configuration

Saramonic SR-M3 Shotgun Microphone - Original Configuration

Saramonic SR-M3 Shotgun Microphone – Original Configuration

This is all well and good, but the Saramonic also has to pass a second test and that is recording quality when used in the field (outdoors). In all the video reviews that I could find on this microphone, everyone was using it for vlogging and, at most, the microphone was used at a maximum distance of about two metres from the subject for testing only. Now I’m well aware that to get optimum performance the microphone should be around 50cm from the subject, but that’s not the sort of work I intend for the Saramonic, or any similar microphone. I intend to record natural audio of subjects often much further away, sometimes significantly so, and therefore the microphone needs to be good enough to capture such sounds. And if I wanted to capture audio of someone talking, I’d use my Lav mic/s as necessary. I also realise that I’m stretching the capabilities of just about any microphone to do what I want, but given what I was able to record on our recent Christmas camping trip, distant bird songs and the like, I’m hoping that this combination will provide reasonable results. Obviously the results aren’t going to be the same were I using a much more expensive microphone, but given some of the reviews that I watched, the Saramonic shouldn’t be a total failure either.

Saramonic SR-M3 Shotgun Microphone - Final Configuration

Saramonic SR-M3 Shotgun Microphone – Final Configuration

But once again I hit a brick wall. The Saramonic most certainly works, but the audio levels at any distance from the microphone simply fade into oblivion, even with the Cayin on full power. The only way that I could get usable audio levels was by using the LS-14 in combination with the Cayin. I really don’t know what the LS-14 is doing when it comes to audio levels, but without it, I can’t get any usable audio. After conducting a series of tests using the Saramonic on it’s own as well as with the LS-14 and Cayin C5, and comparing it to the Rode VideoMicro, I now have a pretty good feel for what works. The Saramonic isn’t worth using on it’s own, as the camera’s audio levels are woefully low; however, with the LS-14 and Cayin, things are very good indeed. So I ran a series of indoor tests comparing the Saramonic and Rode, recording a short voice test speaking ‘Mary had a little lamb, it’s fleece was white as snow’ at one metre intervals out to 10 metres (as far as I could go in the hallway). The Saramonic, with and without the low-cut filter on, recorded quite well right out to 10 metres; however, the Rode faded away far more severely than the Saramonic.

I then repeated the same test but with both microphones connected. The results are quite surprising indeed. The test gives two options, one without any post adjustment to the recorded audio and the second with some adjustment to gain and whatever else I played with in Resolve. I’m far from skilled in audio management at this point in time, so any adjustments that do work is by pure luck only. I also did another test with and without the +10db gain on, just to see what difference this makes and, finally, I did a test with a dead cat (from the Rode VideoMicro) attached to the Saramonic to see how this impacted on the audio levels and quality with the low-cut filter on and with/without the +10 gain on. I separated each test into its own video so that you don’t have to listen through every somewhat tedious test if you didn’t wish to do so. To get the best listening results, you should use headphones. So the results aren’t all that bad given the inexpensive nature of the Saramonic and I guess I’m going to have to see how it works in real world situations before making any final judgement. That said, it’s thankfully quenched any thoughts about getting a Rode VideoMic Pro+ (famous last words?).

So for some final words, I’m 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 only 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 input for nothing more than an audio reference signal or timestamp. The latter is going to have an entirely different setup to the former. That said, I still haven’t come across anyone using similar microphones and internal camera recording in the situations similar to mine, but it may also still be too early for such users to be posting their thoughts. So unless something arises that I haven’t explored, I think I’m stuck with the current combination; though I’m glad it works. And now to Part 8.

Update 1. For some reason I suddenly started to get significant electrical noise when recording, it sounded like amplified fan noise or similar. It took me some time to find out what was causing it and I happened on the source purely by accident. It turned out to be caused by the USB charging cable that connected the LS-14 to the V-lock battery. Why this started just now I have no idea, but as soon as I disconnected the charging cable, the noise stopped. Testing with other USB cables resulted in exactly the same noise. However, further testing revealed that an external power bank connected to the LS-14 produced no noise whatsoever. I have no idea what’s causing this, but I now can’t use the V-lock battery to power the LS-14 and Cayin C5.

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