KVR Audio

qtheerearranger · Post by **qtheerearranger** » Wed Oct 07, 2015 4:18 am

Hello,

pretty basic question here but do patch bays add latency?

In the terms of routing:

Clip playing from DAW --> out of the interface *thunderbolt* --> into patch bay (input of patchbay connected to external compressor -- take the out from the external compressor back into patch bay --> back into DAW?

Dunbar · Post by **Dunbar** » Wed Oct 07, 2015 5:03 am

Compressor: Yes.
Patchbay: No.

planetearth · Post by **planetearth** » Wed Oct 07, 2015 5:34 am

qtheerearranger wrote:Hello,

pretty basic question here but do patch bays add latency?

In the terms of routing:

Clip playing from DAW --> out of the interface *thunderbolt* --> into patch bay (input of patchbay connected to external compressor -- take the out from the external compressor back into patch bay --> back into DAW?

Any time you convert from digital to analogue or from analogue to digital, latency is introduced.

The compressor itself, if it's a completely analogue compressor, will not add any latency, nor will the patch bay. But since you're taking a digital signal, going out through the Thunderbolt D/A device (which is what I assume you mean by "interface *thunderbolt*) and converting that to analogue, and then converting it back to digital again after the compressor does what you want, yes, you will have introduced latency twice.

Your DAW should compensate for that, if you tell it you're using an external, analogue device in the signal path. Since you don't mention which DAW (or Thunderbolt-based audio device) you have, we can't give you any specific way to determine how to check this in your DAW.

But yes, latency will be introduced each time a signal changes from digital to analogue, or from analogue to digital. It takes time for the computer to process this.

Steve

JCJR · Post by **JCJR** » Wed Oct 07, 2015 5:37 am

There will be latency inside the computer from when the software sends sound, to when the audio interface sends analog out, and there will be latency from when the interface receives audio from your compressor, to the time that the computer software receives the signal from the audio interface.

Fortunately most recording software will automatically account for the latency for recording purposes. If your recording software is set up so you can for instance sing a track or record a guitar track along with previous tracks, and if after recording you can play all the tracks in sync, then your software is properly accounting for the latency in recording. In other words, the software knows about what the latency will be, so after it records a new track it is smart enough to automatically shift the new track in time to undo the latency.

So if you want to send a track to the compressor and record the results, the new recorded compressed track should be in pretty close sync with the previous tracks. Maybe not sample accurate in sync, depending on your system, but close enough for rock'n'roll.

HOWEVER, if you want to send a track from computer to compressor, then bring it back into the computer to listen to the compressed track "live" in playback mixed with the other tracks, then it will probably not be in sync because it would be difficult for the recording program to automatically compensate for the latency during play with some of the tracks looped back from output to input. If your computer happens to have 10 ms latency, then the compressed track looping back could be 10 or more ms behind the other playing tracks.

You could get techie in some software to undo the latency by delaying all other tracks except the one sent to the compressor, but that can get weird.

But iust for recording the compressed track, after the new track has been recorded, the new track should play back in sync with the other tracks.

qtheerearranger · Post by **qtheerearranger** » Wed Oct 07, 2015 6:58 am

alright so the patch bay itself isnt anything to worry about but just continue to deal with record based latency on sending out from computer to compressor etc. I use studio one and I ping the latency to keep everything in sync with external gear, very useful.

Thanks for your replies.

stardustmedia · Post by **stardustmedia** » Wed Oct 07, 2015 7:21 am

If the gear is all analog, then NO

Maybe the electrons need some time to travel, but we're talking here femto or atto if not zetto seconds

If you hook up (connected analog) digital gear, gear that does conversion, put them 100% dry (especially effects) and do a ping. There will be some samples of latency introduced by their conversion(s).

If external digital gear is connected digitally, I'm really not sure what happens. I would have guessed that there is no latency. But I could be wrong.

Do Patch Bays Add Latency?