Looking for guidance on audio setup

[SWChris Profile Website]

I've graphed out an audio setup for recording Minecraft LPs that hopefully accomplishes several goals.

1. I want to have a sound board that those on the Skype call with me can react to.
2. I want to be able to monitor my own microphone volume, the sound board, Minecraft, and Skype audio sources in my headphones.
3. Ideally I'd like to get rid of the effect I'm experiencing now where my Mic audio is recorded to the left channel only while my system sounds, Minecraft, and Skype are recorded in Stereo via Fraps. Not horrible if I can't do this in hardware, because I'll be moving to DXTory soon which allows me to separate the audio channels. It just requires an extra step to mix them back together.

I'd like to know two things. First, what's the best way to do this if cost is no object? That's the academic question. The practical question is whether there's a simpler or more affordable way to accomplish all this? I'm slightly concerned about signal interference that all these adapters might cause and whether I'm being needlessly complicated.



Sound Board: Microsoft Surface (already purchased)
Microphone: AT2020 (XLR version)
Mixer: Nady MM-14FX
Splitter: 1/4 Female to dual 1/8th Female adapter
Joiner: Dual 1/8th Female to 1/8th Female adapter (assuming I can find such a thing, it's proving... difficult)

Cables
Sound Board to Mixer: 1/8 Male to 1/4 TRS Mono Male
Mic to Mixer: XLR Female to 1/4 TRS Mono Male
Mixer to Splitter: 1/4 TRS Mono Male to 1/4 TRS Mono Male
Splitter to Computer: 1/8 Male to 1/8 Male
Computer to Joiner: 1/8 Male to 1/8 Male

[Nullmatrix Profile]

The best way would be to use a mixer for all the inputs. that way you can have all the inputs adjusted to the same level and you can control the output better. For your layout you will have both mono and stereo that could cause some imbalance issues with it. You can monitor the output from the headphones and output the mixer back into you pc and record that way if your budget allows.

[SWChris Profile Website]

Hmm you might have to draw me a picture, because Skype and Minecraft are internal to the computer. So I can't output them to the same mixer that my mic and sound board are going into or the people on Skype will get a feedback loop of their own voices in addition to hearing my Minecraft sounds. What am I missing?

[Nullmatrix Profile]

They way you have it drawn is good its the mono connection that is the issue and why your only getting the left or right channel from your mic and sound board.


One question is why would you not use the sound board on the same pc? It would make it easier to do live recordings to get reactions.

[SWChris Profile Website]

Because every time you mouse away from minecraft the menu screen comes up. Doesn't make for good video. Also my microphone is a mono mic, like most mics. But nobody else seems to have the issue. Either that or they've found a way to account for it.

[SWChris Profile Website]

Okay, I think I've got it. I need a better sound mixer that allows me to create a mix minus. That way I can feed my computer's audio into the mixer along with my mic and surface like you suggested and monitor all three sources with my headphones. But I can then cut out my computer's audio and only send the mic and surface audio back into the computer as a mix minus so the people on Skype can hear me and the Surface, but not their own voices.

Then I can either trust DXtory to capture the skype audio plus minecraft audio plus mix minus source from the board, or route the full mix of the audio to another computer or mp3 recorder that will record it.

Now I just need to find a mixer board that'll handle that. Any suggestions?

[ToucanMonkey Profile]

Sort of sad I didn't see this post earlier or I would have replied earlier. I use this mixer: http://www.amazon.com/Behringer-802-Pre ... =xenyx+802

I have two outputs going out of my computer into the mixer into individual channels so people on skype won't hear echo of themselves while hearing my computer audio. Going into the mixer I also have XLR mic. Leaving the mixer I have Mix- using FXSend and Mix both entering my computer. This way I can hear all audio by plugging into the mixer. You might want to look into the Behringer 1202 or the 1002 because they have more channels if you fear running out of inputs.

[SWChris Profile Website]

Actually, thanks ToucanMonkey! I did get the Behringer 1202FX because of the onboard effects processor and I enjoy playing around with toys like that. So far it's working fairly well for what I need it for.

Now, the FX Send jack... is that just a regular output? Or does it do something with the audio?

And also the only issue I've experienced so far is that the audio input is phased a bit by the mixer for some reason, so some of the sound board sounds I play from my Surface come out garbled and barely audible. Using Audacity's phaser plugin I could phase them just a little bit to make them audible, but the plugin also has the side effect of distorting the sound file slightly. I've encountered this issue on other mixer boards. The only inputs that this doesn't happen on are the Tape In inputs. Does anyone know why that could be?

[ToucanMonkey Profile]

FX send jack is stereo out and in my research it is just a regular output. On each channel you can control what is being sent out through it vs the main output. I know that tape inputs don't modify the sound whatsoever so that is probably why it sounds clear. Did you properly set your levels? Do you have any FX on that could be distorting it?

[SWChris Profile Website]

FX is off, and levels are set correctly. When I just use regular headphones to monitor the sound without the mixer board, everything plays at a set volume. But when the Surface is routed through the mixer board, different sounds play at different volumes depending on the frequencies in the sounds that manage to avoid being phased out. I've had this same phase cancellation issue crop up on two separate boards, and one was using an XLR input and this one is using the 1/4" input.

You said earlier that you have two outputs going out of your computer into the mixer into individual channels so people on skype won't hear echo of themselves while hearing your computer audio. The way I'm currently avoiding that feedback issue is to have a single output going out of my computer from the Speaker output into the Tape In input, and then routing the Tape In to my phones/control room channel instead of routing it into the main mix. I'm a little curious if your setup will help me with this issue. Can you describe exactly why you have two sound outputs going from your computer and into your mixer board, what inputs on the mixer they're going into and what sounds each of those outputs carries?


Sorry for taking so long to get back to this.

[ToucanMonkey Profile]

My setup was setup like yours previously. I believe the way I have it set up currently fixes this issue. In Windows sound, I have one output set as my default. This output leads into my mixer and has the FX and main channel mix on. The other output is selected as my output in Skype and Mumble. This goes out of my computer and into my mixer, but the FX channel is off, and the main channel for it is on. The FX channel send (my Mix-) is what I have selected as my mic in skype and mumble.

[SWChris Profile Website]

Hmmm, yeah I guess there really isn't any way around it. I'll have to live with the phasing if I'm going to have a soundboard plugged into my mixer board. I wonder how the radio shows do it? They probably have an even fancier mixer board with two Tape In inputs.

[ToucanMonkey Profile]

I'm not sure why you are experiencing the phasing, is anyone on the googlez experiencing the same thing?

[SWChris Profile Website]

Well I've experienced it on two separate audio boards made by two separate companies. And the only reference to this on Google that I can find is someone who had phasing issues when live mixing a concert, but he wasn't using the same type of setup. I think this setup is pretty uncommon since the Tape In ports are typically used. I just don't have enough of them.

I think I'm going to toss a hail mary over to Eric Fullerton's twitter. He runs The Shaft podcast and they have a sound board setup on an iPad. I'll ask him what he uses and hope he replies.

[SWChris Profile Website]

I think I've just had a Eureka moment.

So the audio file was in stereo. I tried converting it to mono because we know that phase cancellation issues are caused by the left and right channels being the inverse of each other. But that didn't do anything. The mono audio file was still getting cancelled out.

Other anomalies I encountered were that only certain stereo files would have phase cancellation, while others were exactly the same, and while actual mono files were still audible, they would still encounter some phase cancellation, resulting in reduced volume. It just wasn't as bad as what would happen to the stereo files which could barely be heard after going through the mixer board. Nothing here seems to make sense, right?

Well I found a way around it. First, instead of just converting one of the stereo files to mono, instead I deleted the right channel and exported as stereo. This resulted in an audio file with only the left channel intact. When I played it through my mixer board, it sounds completely natural and comes through both channels. Why does it do this?

Well, here's my working theory. And I think the reason is a result of two variables acting at the exact same time. The first variable is the way the sound is handled as it travels from my Microsoft Surface into the mixer board. The type of TRS 1/4" cable I'm using that goes from my Surface into my mixer board is a stereo cable. But the 1/4" input on the Behringer 1202FX is a mono input. So Windows outputs a mono audio file through the sound card by duplicating the signal into both left and right channels. Both signals then travel into the mixer board where they are recombined into a single mono signal, which is where the phase cancellation happens. For some reason being split or duplicated into stereo and recombined into mono doesn't work very well, and in terms of keeping signal integrity you really want to avoid unnecessary conversions like that. So my solution for mono files is to convert it to stereo and invert the right channel. Or I could just get a mono TRS 1/4" cable.

Now this shouldn't be a problem for stereo files, right? That's true, normally it wouldn't be. That's why the sound files I downloaded from commercial audio sites work just fine. The joke drums and dramatic stinger sounds play at full volume with no funky artifacting. But here's the second variable. The stereo files that were encountering phase cancellation were recorded directly off of a starwars.com sound board. The tricksy audio engineers over at Skywalker Sound inverted one of the audio channels! They knew any signal traveling through a mixer board would be converted to mono and cancelled out. I guess because they didn't want radio shows ripping off their sound effects?

At any rate, inverting the right channel on these files solves the issue. So we're in business! Thanks Toucan for helping me troubleshoot this.

Now all I need is a decent sound board app for Surface. I'll probably have to make one in Flash.