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Send delay problem

Posted: Sat Aug 02, 2008 7:21 pm
by rhythminmind
If you create sub bus groups for instruments & FX, (Drums, Bass, Synth, voc's, FX, ect) The fx return outputs in a bus are delayed/out of time with the rest of the sub buses. This is a very basic mixing procedure & a big issue for me.
These buses are sent to the outputs of my audio interface when i mix OOB with an analog setup. Or if i just want to record these buses to audio to make stems for archive/remixing. But i have to manual offset the send returns. Anyway around this? :?:

Posted: Mon Jan 26, 2009 10:50 pm
by rhythminmind
Is this fixed in Live 8?

Posted: Tue Jan 27, 2009 2:53 pm
by rhythminmind
I've had people question what i'm asking. I'll explain deeper.


There will be a uncompensated latency on any return track sent to a bus.
I found this out while doing a remix for 3am. I had a large Live session and i wanted to create remix stems with Live's export track feature. So i made group buses like Drums, Bass, Lead, & FX. I then routed the tracks to the buses & noticed my tempo delay FX were off time. My session had a few intense vsti's & FX so the audio engine needed to use a lot of plugin delay compensation. The more compensation needed the worse the FX bus latency will be.

I made a simple example project
bus delay Project.zip

This project has one drum loop sent to a drum bus & 2 identical FX sends with the inverted phase utility plugin.
Send A outputs to the FX bus
Send B outputs to the master

Turn the sends fully up one at a time.
Send A will pass a phasy delayed bus signal.
Send B will properly cancel do to the inverted phase.
These are the exact same FX sends performing differently just do to bus routing.

It's not a large latency in this project but in a real world situation with many FX & VI's that latency will grow much bigger.
It was enough for me to stop mixing in live. Rewire is your friend

:)

Posted: Tue Jan 27, 2009 3:50 pm
by Bunky Freaks
It is simply impossible to correct the latency for send tracks which are rerouted to audio tracks. You would have to build (imagine 50's radio speakers voice with plate delay) A TIME MACHINE!! to do it. If you think about the implications it get's clear:

Every normal audio track has access to all send channels. Now imagine that you reroute a send track containing a latency inducing plugin to an audio track which itself routes audio via send to the former send channel.. To correct the latency of the send channel Live would have to know in advance what is coming from the send it self. And that would mean Live had to anticipate the future. It's tricky to understand but that's how it is :)

I came across the same issue in Logic, where I setup a routing like you proposed in your project. This led to phase problems because i had a plugin with latency on a send bus which could not be compensated. Routing the send to the master curred the problem.

Simply put: If you want to avoid latency correction problems don't set the audio out of a send to anything other than the master or a physical output.

Posted: Tue Jan 27, 2009 4:35 pm
by rhythminmind
It's possible with engines that compensate for buses as well. DAWs have the ability to read ahead. Off the top of my head Sonar, cubase, Protools hd, & reaper can.

Posted: Tue Jan 27, 2009 4:40 pm
by Bunky Freaks
compensating a bus is a whole different thing. You can not route the audio stream of a bus back to a track which is fed to it. Live compensates latency for busses just fine.

Try your other hosts, latency correction for your scenario won't work.

Posted: Tue Jan 27, 2009 4:45 pm
by rhythminmind
I understand what your saying. but the problem still exists that you can't bus/group FX returns in Live without latency. Something that can be done in other hosts.
The problem is that Live doesn't currently have the ability.

Posted: Tue Jan 27, 2009 4:56 pm
by Bunky Freaks
ah, sorry :D I might have misunderstood what you want to achieve. Grouping sends with delay compensation is not possible in Live, thats true. It might work with delay compensation when no other routing is done besides the grouping.

May I ask why you want to create a submix bus of send channels?

Posted: Tue Jan 27, 2009 5:12 pm
by rhythminmind
I run into 2 scenarios.
scenario one.
Say if i have 6 FX sends & i want to render out stems for a remix or to import into another DAW. I grouped all the FX into a single stereo bus. As i did with my instruments Bass, Lead, vocals and so on. I wanted to send 8 stereo stems to a friend. It's ridicules to render out a whole track for a 5 sec FX part. This is when ability to group & export stems in time with Lives track export would of been nice.

scenario two.
I mix with a 20 channel external console & outboard. I wouldn't want to suckup 12 channels from the 6 FX sends. I would like to Bus them into a stereo FX bus 1st to free up channels on my console.

This is what i want to be able to do in Live that i currently can't. Notice the proof of time alignment by the complete phase cancel.

Image

Posted: Tue Jan 27, 2009 5:27 pm
by Bunky Freaks
rhythminmind wrote:I run into 2 scenarios.
scenario one.
Say if i have 6 FX sends & i want to render out stems for a remix or to import into another DAW. I grouped all the FX into a single stereo bus. As i did with my instruments Bass, Lead, vocals and so on. I wanted to send 8 stereo stems to a friend. It's ridicules to render out a whole track for a 5 sec FX part. This is when ability to group & export stems in time with Lives track export would of been nice.
I see, that's really a shortcoming. I had to deal with the same problem. But i normally don't use more than three sends so I simply render them as individual tracks. Another workaround: you could "solo" all sends and render the master track, that way you get a stereo track with all your sends "grouped". just select the time in arrange view you where your fx is at so it wont take to long to render.

rhythminmind wrote: scenario two.
I mix with a 20 channel external console & outboard. I wouldn't want to suckup 12 channels from the 6 FX sends. I would like to Bus them into a stereo FX bus 1st to free up channels on my console.

This is what i want to be able to do in Live that i currently can't. Notice the proof of time alignment by the complete phase cancel.
Again i hope to understand you correctly here, but can't you just set every output of your send channels to the same hardware out? This would send them all to one hardware stereo out and keep your hardware mixer free for other tracks.

Posted: Wed Jan 28, 2009 3:14 pm
by Bunky Freaks
rhythminmind wrote:
This is what i want to be able to do in Live that i currently can't. Notice the proof of time alignment by the complete phase cancel.

Image
I'm not familiar with Sonar. But in your Sonar project can you activate a send in your "FX Bus" which feeds into your "Drum Bus"?
If you do so I highly doubt this still allows for proper latency compensation. And thats whats currently missing in Live to be able to group sends with the compensation still working:

The option to completely deactivate/remove sends in a track/bus (this is possible in Sonar, as I conclude from your screenshot).

If this individual removal/deactivation would be possible in Live you could group/bus sends with the latency delay compensation still working. Any kind of feedback routing makes delay compensation impossible. So if the sends are disabled this prevents from creating a feedback routing.

It might be a worth a feature request to able to completely deactive/remove sends from a track, which then should make your desired routing possible :)

Posted: Wed Jan 28, 2009 3:22 pm
by rhythminmind
Yes that would work nicely. Worth a feature request.

Re: Send delay problem

Posted: Wed Mar 09, 2011 10:32 am
by TST
I've just been fiddling with this to make sure I'm aware of any slight timing delays in Live and I have found a solution that allows you to make a sample accurate sub group for your returns.

What I've found is:

- If you route any audio from return tracks back into the main mixer via an audio track there is a delay (I know we already know this)
- If you enable sends from the return tracks you can use a final return track set to be a return bus and it stays in time

You do have to set the return outputs to send only though and strangely if you create any audio tracks set to record the master, even if the monitor is set to off, that will suddenly throw off the timings of your return channels!