Workaround for lack of side chain delay compensation

[Kregan]

Hey guys,

I was wondering if anyone knows the absolute best workaround/s for dealing with the lack of side chain delay compensation on a native system.

I'll mainly be doing the classic kick drum ducking the bass/other instruments.

Thank you

[john1192]

use a dummy track to trigger the Side Chain input .. place that track wherever you need since it is only a Detector track ..

[midnightrambler]

Originally Posted by Kregan

Hey guys,

I was wondering if anyone knows the absolute best workaround/s for dealing with the lack of side chain delay compensation on a native system.

I'll mainly be doing the classic kick drum ducking the bass/other instruments.

Thank you

I haven't found one. It's a nightmare if you're running plugins with a lot of latency. You have to keep on top of the trigger track and move it by the number of samples the latency readout is giving, which of course can change as soon as you add another plugin with a higher latency.

If you're after that pumping thing though the
Waves Pumper works a treat. Saves a lot of hassle worrying about the latency of the trigger track. http://www.waves.com/plugins/oneknob-pumper

[midnightrambler]

Actually sometimes disabling the trigger track from the delay compensation works. I forget the exact details as I'm not in front of my computer... Someone else may be able to provide more info :)

[Kregan]

Thanks for the suggestions guys.

After extensive experimentation I think the dummy track is the best option

[OliverH]

Originally Posted by Kregan

Thanks for the suggestions guys.

After extensive experimentation I think the dummy track is the best option

I'm in the same camp as you man. I've been dying for a solution for this but agree that the only solution (albeit painful) that really works is the dummy track thing. But you do need to check in on it as you add/subtract high latency plugins because the offset of your trigger to the sidechained track will change. Huge bummer but I guess nature of the beast for now.

[mr xy]

avid really needs to sort this out IMO. Pretty huge omission.

please vote for this feature

http://protools.ideascale.com/a/dtd/...ns/163679-3779

[OliverH]

Originally Posted by mr xy

avid really needs to sort this out IMO. Pretty huge omission.

please vote for this feature

http://protools.ideascale.com/a/dtd/...ns/163679-3779

just did.

[demodigi]

Hi guys,

I tried to reproduce you're latency issue with but I don't have any comp plugin that both support sidechain AND introduce high latency (like UAD).

But did you take care of the order of the plug-in chain when performing you're tests ?

Because for me, Delay Compensation (ADC) works fine with Side Chain even in native systems.

I made some test using a high latency plug-in BEFORE or AFTER the side-chained compressor and the position of the high latency plug-in makes a huge difference.

My suggestions :
1/ make your tests with mono channels only (side-chain signal is only mono, so you cannot drive a stereo channel with a stereo sidechain signal (or multichannel) in Pro Tools)
=> this is something that should be added to PT IMHO.
2/ try to put a high latency plug AFTER the SC-compressor and see what happen (there should NOT be any issue with ADC).
3/ try to put a high latency plug BEFORE the SC-compressor and see what happen (there should be latency issue even with ADC). In this last case :
=> the main signal is delayed, the side chain signal is NOT -> so of course there is time issues between both signals
=> Solution : create a new Master Fader (not an Aux) and assign it to the side-chain bus, then put the same plug-in (the one placed before the SC compressor) on this MF and bypass it (or put a "trim adjuster" plug and set it to the same amount of delay introduced by the plug-ins chain placed before the SC compressor).

example with "Channelstrip" (used as the Side-Chained compressor) and "Maxim" (used as an high latency plug-in) :

Case 2/ :
Track 1: (drive track)
Send to "bus 1"
Track 2: (compressed track)
inserts : channelstrip (0 latency, key input : "bus 1")->Maxim (1024 latency)
Shouldn't be any latency issue with ADC set to ON

Case 3/ :
- Track 1: (drive track)
Send to "bus 1"
- Track 2: (compressed track)
inserts : Maxim (1024 latency)->channelstrip (0 latency, key input : "bus 1")
- Master Fader ("bus 1"):
inserts : Maxim (1024 latency, bypassed) or trim adjuster set to 1024 samples
ADC must be set to ON

Case 3/ (bis) :
- Track 1: (drive track)
Send to "bus 1"
- Track 2: (compressed track)
inserts : Maxim (1024 latency)->channelstrip (0 latency, key input : "bus 1")->Maxim (1024 latency again)
- Master Fader ("bus 1")
inserts : Maxim (1024 latency, bypassed) or trim adjuster set to 1024 samples (not 2048 because the 2nd Maxim doesn't introduce any latency on the main signal feeding the compressor)
ADC must be set to ON

If you have a UAD card, I think there is special plug-in to make a delay compensation (Delay Comp). You can use it on the Master Fader too (no wasted DSP power).

Don't forget that, in Pro Tools, :
- Master Faders are there to control a summed bus (virual or physical). It is way more powerful and useful as a simple "General" Volume. It is placed BEFORE a Aux track in the signal flow.
- An Aux track is kind of a bus (or a signal) receiver, it is independent from a bus. It is placed AFTER a Master Fader in the signal flow.
- Also, a bypassed plug-in still introduce latency, it is not equivalent to a de-activation (that cancels both latency and CPU usage).

But I don't know what's happening with a compressor that introducing high latency by itself. Try the solution I suggest in case 3/ and tell me if it works.

[OliverH]

Originally Posted by demodigi

But I don't know what's happening with a compressor that introducing high latency by itself. Try the solution I suggest in case 3/ and tell me if it works.

demodigi, drinks for you on me! Now we're really on to something.

I wanted to also give props to member Kregan who also made some interesting discoveries on this whole issue. I think, together, you two have uncovered some critical clues.

Kregan offered up the following in a related thread about the same topic:

"The side chain will only be off if the trigger track has delay inducing plugins and the delay reading has numbers on it. It will not be off if the trigger track is being compensated but does not have delay on its own track.

So the best option I've found is to duplicate and make a dedicated trigger track and make sure it does not have any delay on it. Set up the side chain from that track, configure the compressor settings then everything else takes care of itself. You don't have to worry about delay on other tracks because the side chain will work if the trigger track is being compensated as long as it doesn't have any delay on its own track.

This way you can use all your fancy plugins on the kick track or any other track as long as there is no delay on the duplicated trigger track and the side chain will still be in time!

The only downside is that the compressor won't react in real time to the changes you make to the original trigger track... EQ, envelope shaping etc. But the timing will be rock solid! And you could make changes to the compressor settings after you change the original trigger track/kick or whatever it is."


Now for my observations:

Kregan discovered that if you duplicate your trigger track and make sure it has no delay-inducing plugins on it then ADC partially takes care of the issue, but this is ASSUMING you have no delay-inducing plugins anywhere on your slave compressor track either.

Having the duplicated trigger track be "zeroed" out, so to speak, with respect to no delay being shown in the ADC indicators (not to be confused with compensation amount) ensures that the side chain signal will always be AHEAD in time and therefore it will just be a matter of using the Time Adjuster plugin to manually compensate only for the delay induced by the plugins on the sidechain slave track, as demodigi suggested. I took it one step further and used the new Commit feature in PT 12.4 on my duplicated trigger/drive track so that I actually printed the same sound as the actual live trigger/drive track just to be as close to reality/an analog board as possible, i.e. no delay compensation headaches to worry about ever.

As an experiment, I tried where I instead bused the side chain trigger signal directly from the trigger/drive track (not a duplicate) with a bunch of delay-inducing plugins on it, enough to make it so the side chain signal, when auditioned, was actually BEHIND the realtime trigger track and therefore we'd get back into needing to have to scoot the duplicate trigger track ahead in time in the session in order to compensate.... and I don't know about you, but my whole mission is to avoid having to scoot clips around for this!! So, Kregan's theory helps with this particular issue. It nulls out one of the variables.

But demodigi is offering up another side of the story that is important which is the part about the effect of delay inducing plugins on the SLAVE compressor track. I found all of his theories and solutions to be true when I tested them. Wanted to add that I also tested using a compressor that at least induces a little but of delay, albeit not a ton (64 samples at 48k), which is Waves' C6 Side chain version. I really love this plugin and for me it's especially cool for carving out issues in the low end (i.e. kick and bass) or using it to duck frequencies out of loud guitars or synths that get in the way of vocals or other melodies, but of course a lot of these tricks rely on using it in a side chained setup... Point is, using a compressor plugin that ALSO induces some delay does also need to be dealt with but I found that it's a pretty easy adjustment.

Using a Waves C6 on the compressor slave track, this induced 64 samples of delay on that channel. So, using demodigi's theory, I created a mono Master Fader for the bus that was feeding the slave track from my test kick drum trigger track, inserted the Time Adjuster plugin, set it to 64 samples, and voila, when auditioning my main trigger kick drum track alongside the auditioned side chain signal input on C6 (make sure its S/C Mode is set to 'Wide'), they were perfectly in time! [I listen to the original trigger track and the side chain audition to take out any guess work on how in time the two are, FYI...]

If I inserted another delay-inducing plugin AFTER the C6, for instance, the UAD 610-B plugin which adds 1143 samples of delay to the channel, I did nothing and the two were still perfectly in time, just as demodigi had said in his previous post.

Now if I move the UAD 610-B plugin BEFORE the C6, we've got issues again. But no worries, I just open up the Time Adjuster plugin on the Master fader channel for the feeder bus, change the delay time to be 1207, and boom, we're back in business. Why? Because I've got 1143 samples PLUS 64 samples of delay to impose on that side chain signal coming into my slave track (1143+ 64 = 1207 samples TOTAL).

What happens if I change the C6 to instead be the stock Avid dynamics compressor/limiter plugin, with the UAD plug before it? I can change the Time Adjuster amount to be 1143 samples. Why? Because the stock Avid compressor has no latency/induces no delay, therefore all I need to worry about is matching the delay from the UAD plugin which is 1143 samples.

What happens if I move the UAD plugin AFTER the stock Avid compressor in the chain? I can completely BYPASS the Time Adjuster plugin on the Master fader for the feeder bus and they are still perfectly in time. Why? Because, as demodigi theorized correctly, delay-inducing plugins that come AFTER your side chain compressor don't affect ADC being messed up. Only when they're placed BEFORE are you needing to address the issue.



What's the moral of this whole loooooong story? From what I can understand so far in my initial tests, if your duplicated trigger track has NO delay on it from plugins (either by removing them all or committing effects from your main trigger track to a new audio file), you just need to match whatever TOTAL delay is induced by plugins up to AND including (from the top down of your inserts chain) your side chain plugin compressor on your slave track by entering this amount into the Time Adjuster plugin on your Master fader track for the feeder bus. Any delay induced by plugins that come AFTER your side-chained compressor plugin need not be applied to the delay compensation amount in Time Adjuster. You may have to briefly deactivate plugins that come AFTER your side-chained compressor plugin in order to see what this critical total delay amount is that you would enter into Time Adjuster. Just make sure you have the 'Delay Compensation' indicators for channels turned on to be visible in your mix window.

So, if you're able to keep an eye on all of this, it seems this may be one of the cleanest possible workarounds for this pesky lack of automatic side chain delay compensation issue! Still a pain, sort of, because it gets in the way of creativity still, but it at least allows you some freedom to mess around with plugins, adding & subtracting as needed as your session progresses without having to scoot audio clips around.

Need to test this more rigorously now in more complicated real world scenarios with bigger, more complex sessions... but so far this is working for me.

Curious if anyone else gives it a shot and what they think?

Peace.