The overkill audio build
professional SOUND for twitch streaming with OBS
Hi, I'm Ian, a video marketing expert and an lifelong avgeek. I'm learning to fly for real, and I do a lot of flight sim on X-Plane. This is a rundown of how I upgraded my audio for Twitch streaming with OBS and a second computer.
I had been streaming X-Plane on my sim PC and with static PNG graphics in OBS, the performance impact was minimal. My friend has been working on web-based graphics overlays that dynamically connect with PilotEdge, when using those through OBS, I noticed a significant drop in FPS. Going from about 60+ to less than 30.
So I wanted to offload OBS to my laptop. Sending video was easy enough, I used a Blackmagic UltraStudio Mini Recorder. It's capped at 30p capture at 1080 resolution, but the de-interlacing in OBS was good enough that I felt comfortable running at 1080 59.94i.
Audio was a lot more difficult. I have things set up to output X-Plane's ambient audio on speakers, and then PilotEdge is hooked up to a lightweight Plantronics Starset. OBS handled all this wonderfully when it was on the same PC, but now I needed a solid way to pipe all that audio out, mix it, and send it into the laptop. I had some simple audio components because of my work, but I wanted a rock solid solution and that required some extra parts. Here's how everything came together.
GETTING THE SOUND OUT
In order to hook into the pro mixer I have, I needed a pair of external USB sound cards, hopefully ones that either output a pro line or mic signal. My same friend who's working on those overlays recommended a digital DI box by Peavey that outputs to two XLR jacks. It rocks.
It's a step above some similar USB cards that I've found and it includes circuitry to eliminate electrical noise and ground loop hums. This is really nice because PCs are noisy and most cheaper external sound cards don't output truly clean audio. I have two of these, one for X-Plane ambient sound, and the other for PilotEdge output.
MIXING THE SOUND
Everything gets sent into a Behringer 1002b mixer. With 5 XLR inputs and a total of 10 channels of audio, I have a lot of granular control. It's very easy to adjust the mix to compensate for a quiet controller, or an extra loud plane. In order to use a typical pc headset with a mixer, you need to supply it with 'plugin power.' This is sort of a lower voltage version of phantom power and it's tricky to find the right adapter. I found a nice one from a company that makes a lot of small adapters and power modules, Sound Professionals.
ROUTING THE SOUND
Two 1/4" patch cables go from the mixer's main outs to a Tascam USB audio interface that I typically use for recording into my Mac. I use Tascam's app or hardware knobs to tweak the signal levels and OBS recognizes the input as a generic USB soundcard.
The mixer has both monitor and FX Send submixes, so I can isolate my headset mic and just send that back to the PC for PilotEdge. With the other submix, I send ATC to my headset plus my own mic input to simulate sidetone.