Adventures in sound: My ongoing struggle with audio fidelity

Steady on, because this post is not really about adventure games per se. It’s about audio, specifically the challenges of recording clean audio, and it gets a bit technical. So if you don’t give a shit about microphones, audio devices, gating, compression, and whatever else goes into that stuff, you’re best off reading something else. I’ll get back to talking about adventure games next time (probably).

Not an insignificant amount of people who are watching my Let’s Plays on YouTube have noticed that my audio setup is not the greatest in the world.

Me mix good audio.

Specifically, there is an omnipresent hiss in my commentary audio, which — although barely noticeable when you’re listening to it on speakers — becomes very irritating when listening to it with headphones.

It’s something that’s been annoying me a lot, too. Mostly because I was under the delusional impression that I was actually okay — not great, but okay — with audio production. I’ve produced music since my early teens and you’d think I would have at least a rudimentary grasp of what constitutes good audio.

Before I go any further, let me just explain my setup real brief. When I record videos, I use OBS Studio to capture the game footage as well as my facecam. (Yes, I have experimented with divorcing my facecam from OBS as well and filming that with a separate camera, but that’s a topic for an entirely different post.) I don’t use OBS for recording my commentary audio, though. I have my microphone muted in OBS, and I use Audacity on the side to record a wav-file of what’s going into my mic. That way, when I’m editing, I can control the balance between commentary audio and game audio separately, so one doesn’t drown out the other.

My microphone is a Sennheiser E835 S that, while admittedly getting on in years (it’s over a decade old now), is still going strong. I’ve been to a music shop and had them test it out — the microphone works fine. Granted, it’s not a studio mic — it’s made primarily for singing on stage — but it’s a good quality mic.

The mic goes into a similarly aged M-Audio MobilePre, which — if the internet is to be trusted, which it rarely is, but there seems to be a large consensus on this — is not a bad piece of hardware. It’s got 40v phantom power (not that I need it with my directional Sennheiser mic), and it’s got a built-in preamp. Meaning the audio signal going from the mic through the device into the computer should be pretty strong — at least, in theory.

This little beauty has stood by me for more than a decade.

In practice, though, that’s not the case. I have to turn the gain on the MobilePre up very high to get anywhere near audible levels. And when you turn the gain up that high, you get — yes, you guessed it — noise. A lot of it.

And even then, the mic volume still isn’t very loud. So I would use Audacity’s built-in compressor tool to level out the mic audio so I got a nice, loud waveform. But that means boosting the signal even further once it’s already been recorded, and guess what that means? The noise gets even louder. During quiet parts when I’m not speaking, it sounded like I was doing my commentary inside a wind tunnel.

Of course, there are ways around that. After applying compression, I would then apply gate so the signal would go completely silent when the volume dropped below a certain level (i.e. when I’m not speaking). It helped a bit, but there was still audible noise when I was speaking.

That’s why I went out and bought a new audio device, thinking that perhaps my dear old MobilePre had outlived its usefulness. I reached out on Twitter and asked if anyone knew about some good — and, importantly, low-noise — audio devices. I got some good recommendations, but ended up going with Rebecca McCarthy’s suggestion of a Presonus Audiobox 96. She’s a voice actress and uses this device to record her voice-over, and she swore it was quiet.

Problem solved, right?

Well, the thing arrived, I gingerly plugged it into my computer, and … well, fuck. Still getting a lot of noise. Worse still, when I tried to record a game, the Presonus wasn’t playing nice and wouldn’t share its audio output with both the game and OBS at the same time. With OBS running, the game would be completely mute.

Now, I know that I could have experimented more and perhaps found a solution to the audio sharing problem. But I bought this thing because I thought it would magically fix my audio hiss problem, and it didn’t. I even tried a different mic — a Superlux HO-8 condenser mic I stole from a friend of mine years ago, which uses phantom power, and it sounded even worse, so my guess is that mic is not doing terribly well.

There was nothing wrong with Rebecca’s suggestion. I’m sure the Presonus is great at what it does. I mean, Rebecca says she uses it and has no problems getting nice, low-hiss audio, and she’s a professional. The problem wasn’t with my choice of audio device. The problem seems to lie within my computer itself.

So the Presonus went back in its box and back to the store I got it from. It would seem that the MobilePre was innocent after all, and the problem didn’t lie with my audio device at all. Nor, as it turns out, my audio cable (I bought a brand-new XLR microphone cable, just in case), or my microphone (which I had a professional audio engineer test out). Not only that, but I also borrowed a third audio device from the music store where I tested the mic, and that one didn’t work at all — all I got were some very worrying clicking noises in my headphones — so that went back as well.

Now, I know what the audio savvy are going to say: Pre-amps. Stick a pre-amp in between the mic and the MobilePre, and it should boost the signal before it reaches the computer — hopefully without adding any more noise to the signal. I haven’t tried that yet because, shit, do you know what those things cost? A lot, is the answer. Also, the MobilePre already has a built-in preamp, so you’d think that would be enough!

Another suggestion that’s been thrown my way has to do with the actual voltage that goes into the MobilePre. One of my Patrons posited that perhaps the MobilePre itself is not getting the power it needs from the computer to process the power that the preamp inside and the microphone requires. He suggested that I buy a USB hub that goes between the computer and the MobilePre, which (in theory) should be able to process the voltage coming out of the computer in a more sensible way. That’s at least something I can try out in the future without breaking the bank.

Maybe this will be what my audio setup looks like in the future.

In the meantime, I have experimented a bit with ways to reduce the hiss with software. Audacity’s filters aren’t terribly user-friendly, so I haven’t had much luck using its noise reduction filter to quench the noise. However, it turns out that Adobe Premiere Pro has some pretty good audio filters built in — even the older version I’m using. It has compression, which means I can boost the sound, and it has a very good noise filter that does manage to bury much of the noise at the mild expense of losing some minor treble range.

When I used the noise filter in Audacity, it sounded like I was speaking into the mic through the wall in an entirely different room. With the Premiere Pro filter, it actually does what I expect it to. So now, the only filter I use in Audacity is the gate, not applying any audio leveling or compression, and then I pump that into Premiere and work with Premiere’s filters to make it listenable.

That’s where I am now. Still using the same old setup, just getting better at using audio filters. Maybe someday I’ll work out exactly why my I need to turn up my MobilePre so ridiculously loud, but for now, I hope the audio annoyances are at least becoming more bearable for those of you watching my videos with headphones.

The first video to use this new setup will be episode 4 of Observer, which comes out Thursday 28th, 2017. And I will of course continue to fine-tune it as I go on editing. You know, until I stumble upon an actual solution.


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