Audio help.

[Priestsan695]

Tldr version: is there a way to mute and audio source on Monitor but still have it output to stream/recording ?

The long version: we are using obs to run our church services and to record and steam the service. From the computer we are using we play music videos and the output for them feeds into a digital soundboard and from there to speakers. We also have an output from the soundboard going back into the pc as an audio source so we can record/stream what's being spoken over the microphones (we use 3-4) the problem lies with that audio source feeding back into the soundboard same as how the music videos feed in. This cause a nasty echo loop that I don't know to get rid of. Is there a way to mute the mics from going back into the soundboard, but still have them play on the recording/stream?

 

[Lawrence_SoCal]

Been there, done that
The question is when you are playing the video, how are you doing that?
-side note: whole long issue regarding copyright to not ignore, as that can get your channel blocked by automated bots

short answer - yes, should be doable, but how exactly depends on info you haven't provided

I'd be inclined to play video as its own source in OBS, and then mute the sound system (soundboard/mixer which is a separate specific source in OBS, right? you aren't using Desktop Audio hopefully) altogether. That way, you have cleanest audio and video as direct from file, via Media Source/VLC Player on OBS PC, to stream.
- Back during lockdown, when intermixing live and pre-recorded House of Worship content, I found the need for Advanced Scene Switcher plugin (often referred to in these forums as AdvSS), to automate a bunch of the transitions (ie had a scene with pre-recorded content, and not the house mixer... so we couldn't make a mistake) https://obsproject.com/forum/resources/advanced-scene-switcher.395/
- Then I also used the Media Controls Plugin <https://obsproject.com/forum/resources/media-controls.1032/> so when playing pre-recorded content, I could see a timer for remaining time in video. AdvSS would auto-change scenes when video ended as I configured. I'm not sure if latest OBS Studio UI changes negate the need for this plugin?
One consideration is whether you want background sound (ie congregation singing along) as part of the stream. Obviously, if you mute your mixer/soundboard, you won't pick up audience participation.

Our older analog mixer (soundboard) has an AUX mix, meaning I setup a separate mix for mics for piano, choir, and pipe organ (which do NOT need in-house amplification (sent to front of house speakers). At times I'd like to mute a few mics. The challenge is our mixer is designed for set and forget, and in a small closet; and is older analog.. so I can't remotely adjust individual channels on the mixer (as can be done with some newer mixers). You also have to consider with your worship style, and volunteers, etc, the expertise of those (if any) running livestream and /or mixer. Some worship styles have dedicated sound engineer for every service (praise/band style, and others)... if that is your scenario, you should have one mix for in-house amplification/speakers., and another for livestream audience. And sound engineer should be able to control both, live during service. There are other scenarios. Our setup is no sound engineer, no-one touches mixer unless something is really wrong (which is uncommon... once every 6 months or so??). However, we do have a person running the live stream, changing OBS scenes (intro, welcome, then camera video width (I configured 3 options), advancing Service Bulletin (PowerPoint) to match service, acting as Digital usher, etc. The audio in our case, is the AUX audio mix from our mixer (in stereo). As such, we do NOT have access to individual mic channels in OBS.
MacOS (vs Windows) benefits from a better audio subsystem, and depending on your mixer, mixer config, and connection, you might be able to configure your mics to be visible in OBS. However, as sound people will tell you, for cleaner sound (which is more important than video), it is usually better that handle multi-channel audio outside of OBS (in the mixer itself, or in a DAW (digital audio workstation, ie software mixer). My desire, eventually/maybe, is to get a DAW running on our OBS computer (which has plenty of compute power to run OBS Studio and the DAW at same time), and handle some simple audio mixing in the DAW, then outputting that to OBS Studio. How easy/hard that is, and at what cost, depends on your specific gear (sorry.. it depends)

so - not that my expertise is in sound (it isn't, by a long shot). But telling us exactly which mixer, and how that is connected to OBS (Dante over network, USB, firewire, or ??), and is the mixer configured for separate in-house speaker/amplification vs livestream? will help.
And within OBS Studio, how are your sources setup? posting you OBS Log (per pinned post in this forum) would be helpful

There are a number of us in these forums helping out with House of Worship streaming. hopefully we can get you sorted out quickly (though I normally don't check these forums over the weekend)

 

[Priestsan695]

Going to do the best to explain, I'm no sound engineer, but trying to learn (our sound specialist left the congregation a short while back) we have a 32 channel board, different instruments and vocal mics spread out among the 32 channels, basically everything is full and eq'd and ready to roll. Output from the board mxes everything and goes out to the speakers in sanctuary. We have an out labeled "recording" that then outputs all that in the 3.5mm mic port on the pc. (This is set to default in inside OBS) we have a digital output connected to the board that outputs sound to the board itself so we can play the videos. I do have the videos setup as media sources in obs and I can control the volume ect from obs. All videos are set to "monitor and output" so is the default mic (coming from the board) currently we have to mute the pc on the soundboard when the pastor speaks, otherwise he echos because the microphone is feeding back into the board from the digital out.

 

[Priestsan695]

I should also include that sometimes when praying for members our pastor likes to play some instrumental music softly in the background. This is where we run into our big issue and with both at the same time it starts the echo loop because we have the microphones going into the board to be mixed, the going into the computer via the mic port, then back out through obs output into the board again.

 

[AaronD]

Self-taught sound guy here, system designer, and I run the rigs that I build. The easy solution, as I see it, is to have the OBS PC play nothing. It only captures. A different PC plays media. Then the sync issue is the same for everything and so it all lines up anyway. Also less source switching.

It does mean though, that you now need a physical capture device between the two PC's, to get the picture into OBS. Sound goes through the board as usual. Just move the existing cord for the video soundtrack, to the new playback machine instead, so OBS can't feed the board even if it wanted to.

OBS then has only one audio source at all, and it comes from the board. Absolutely everything runs through there.

For sound quality from a video file, that you know exactly what's it's supposed to be...it really doesn't matter if it's bit-perfect on the stream. No one's going to notice. We listen to the amplitudes of a bunch of different frequencies, not the exact values of a bunch of samples. Go ahead and run it through a D/A/D conversion or two with processing in between. It'll be fine. The stream encoder is going to do far more "damage" to it than any of that, and nobody notices.

 

[AaronD]

The built-in Mic input on a PC is probably the worst possible quality that you could have. I'd go for a USB line input that actually IS a line input.

Don't get a chunk of plastic that has a USB connector and the same cheap chip that's designed to go inside the noisy box and so its performance isn't any better than that. Besides, they often don't have line inputs anyway. Only headphone and mic.

Get something that has some USB cord on it, to get it away from the noisy box, and read the spec sheet to see that it really does accept a real line in. Not mic, not phono, but line in.

Then once you have that, you'll want to bus-compress your stream mix before it leaves the digital board - I like a really-soft-knee limiter and set the threshold to "ride the knee" most of the time - and use that compressor's makeup gain to put it within 1dB of full-scale as received by OBS through your for-real line input. Instant attack, hold and release by ear, starting around 150ms or so.

If you want to calculate it, you'll need to recognize that professional line level is 11dB higher than consumer line level. So if your line input uses the consumer standard, that's perfectly fine, but you'll have to remember that full-scale in OBS is going to be about -11dBFS on the board. Just set your post-compression gain that much lower.

For ours, I also have the master fader for that mix all the way up, and the compressor's makeup gain that much lower again. That way it's both impossible to bump it up too high by accident (because it really is right up next to clipping, and OBS sometimes thinks it *is* clipping, but it's impossible to *actually* clip if you keep it set right), and easy to fade out and back up to *exactly* that spot if desired. But my primary control for that fade is in OBS anyway. It mostly just makes it less error-prone for the FOH engineer.

 

[Lawrence_SoCal]

Going to do the best to explain, I'm no sound engineer, but trying to learn (our sound specialist left the congregation a short while back) we have a 32 channel board, different instruments and vocal mics spread out among the 32 channels, basically everything is full and eq'd and ready to roll. Output from the board mxes everything and goes out to the speakers in sanctuary. We have an out labeled "recording" that then outputs all that in the 3.5mm mic port on the pc. (This is set to default in inside OBS) we have a digital output connected to the board that outputs sound to the board itself so we can play the videos. I do have the videos setup as media sources in obs and I can control the volume ect from obs. All videos are set to "monitor and output" so is the default mic (coming from the board) currently we have to mute the pc on the soundboard when the pastor speaks, otherwise he echos because the microphone is feeding back into the board from the digital out.

One of the first things I did was DISABLE in OBS Settings all Global Audio devices. My Audio sources are those I've specifically determined (pre-recorded video, mixer, etc). Not sure that would help in your scenario though
Did you issue start after sound specialist left? If yes, I'm inclined to think he/she was making adjustments on the mixer during the service to avoid echo. And that isn't happening now.

I should also include that sometimes when praying for members our pastor likes to play some instrumental music softly in the background. This is where we run into our big issue and with both at the same time it starts the echo loop because we have the microphones going into the board to be mixed, the going into the computer via the mic port, then back out through obs output into the board again.

In this scenario, assuming you meant to indicate that the "instrumental music softly in the background" was played via the OBS Studio computer? As that is playing via Sanctuary speakers, and picked up by Sanctuary mics, I'd be inclined (without knowing more) to NOT have OBS capture the audio directly from music/video file. Instead playing music/video file at Operating System level (not inside OBS) and send that audio to mixer. Now OBS only gets is video/music audio via the mics, and now, no echo?

Self-taught sound guy here, system designer, and I run the rigs that I build. The easy solution, as I see it, is to have the OBS PC play nothing. It only captures. A different PC plays media. Then the sync issue is the same for everything and so it all lines up anyway. Also less source switching.

Understandable suggestion. but I suspect (hope?) that isn't necessary/is overkill.
Especially with the audio routing mentioned, and needing to mute the OBS PC when pastor speaking. To me that indicates a more basic/fundamental issue with the overall audio setup. I get why, I think..but I don't like it.

It does mean though, that you now need a physical capture device between the two PC's, to get the picture into OBS. Sound goes through the board as usual. Just move the existing cord for the video soundtrack, to the new playback machine instead, so OBS can't feed the board even if it wanted to.

OBS then has only one audio source at all, and it comes from the board. Absolutely everything runs through there.

That's my idea, without the extra computer. BUT, there could also be some other considerations I'm missing that make this non-viable.

agree the 3.5mm TRRS cable is least ideal. but depending on the specific mixer, and other connected devices, it may have been a reasonable compromise (especially if OBS quickly setup as start of pandemic lockdown 3.5 years ago... then don't fix what isn't broken?)

sorry...totally 'under the weather' at the moment, so apologies in advance if any of the above was off-point/rambling/etc