Delay compensation in a hybrid setup

[Unit7]

I'm changing from analog to hybrid the coming weeks and I've tried to wrap my head around this but can't..
Before going to the final mix bus I'll be sending the whole mix to an Aux and insert an outboard compressor to blend in some parallel compression. All good so far. But if I'll send that (already compensated for) signal to yet another Aux with yet another outboard insert, will PT then calculate the added delay correctly?

I guess this has been asked/discussed earlier and I apologize for not wading thru the threads but hopefully you hybrid folks know this

[Darryl Ramm]

Even without hybrid… this will have problems if you exceed the delay comp limits, and there are known bugs with hardware insert latency that can show up with a H/W insert following a plugin, or if ignore errors is enabled (not sure how that affects hybrid).

So as with any other use of Pro Tools ADC or general latency behavior I would be paranoid if it’s working correctly or not. And you can let us know how it does.

[Unit7]

Originally Posted by Darryl Ramm

Even without hybrid… this will have problems if you exceed the delay comp limits, and there are known bugs with hardware insert latency that can show up with a H/W insert following a plugin, or if ignore errors is enabled (not sure how that affects hybrid).

So as with any other use of Pro Tools ADC or general latency behavior I would be paranoid if it’s working correctly or not. And you can let us know how it does.

Thanks for the warning about bugs and stuff!

I totally get that I'll run into problems if I exceed the comp limits, hybrid or not. But that wasn't really part of the question.

Bugs or not, what I'd like to know if PT's delay compensation is designed to "understand" the scenario I described and add the delay comp accordingly.

And I don't think I'll have to be paranoid. Blending in a parallel signal that is not in phase is quite audible

[Unit7]

I'm so sorry.. I posted in the wrong forum. I'm on an Apple computer.

Also I just want to be clear that with "hybrid" I don't mean PT in hybrid engine mode, but instead a hybrid mix setup, with analog outboard hooked out to the I/o's of Avid interfaces

[Darryl Ramm]

You are asking a questions that is basically will Pro Tools ADC work correctly. The answer is probably it will work correctly, or maybe, or toss a coin, or buy a lottery ticket.

ADC might work OK, but there are sure as heck some embarrassing bugs in there that cause folks grief, and there seem to be more bugs reported in hybrid (which you can search for on DUC). (edit: thanks for the clarification you are not using Hybrid engine).

There is nothing special in what you are describing that ADC should not do. Outside of delay comp limits and bugs, which is why I mentioned them. And I specifically mentioned bugs because of an open bug that hits with H/W inserts (PT-293686)--at least native inserts, unclear with HDX.

The only three things that ADC really does anywhere different that folks should have to worry about are 1. not compensating for latency on a master fader. And that's because at that point the signal is supposed to be "done" and Avid also wanted some place you can stack up high latency plugins and not have ADC try to compensate them. And 2. Aux I/O inputs and outputs are is just not guaranteed to align with other interface outputs. And 3. H/W insert delay compensation can take some effort to set up properly.

On #3: you may need to have the hardware insert delay compensation adjusted correctly, and what might be needed there depends on the details on the interface(s) being used. I've written about that before several times on DUC. But you may need to manually align the hardware insert latency using the track ADC +/- adjustments. A entirely crazy mess for the industry leading DAW, but even in the worse case it's all workable given some effort. And this can apply to Digilink as well as CoreAudio interfaces. It depends on the details of the exact interface used.

Many of the problems of folks using external mix busses etc. come down to not setting up correct ADC adjustment for the H/W insert combined with running into one or more (often known) ADC/latency bugs that throw them for a loop (and would reasonably stop any sane person from being able to get stuff set up correctly... so again you have to be on the lookout for bugs). Because your Prism ADA8XR does not emulate the Avid HD I/O hardware latency you do need to adjust the latency there if you want stuff to line up with your Avid hardware. Prism document that well.

[Unit7]

Thanks again for your input!! Sounds like this could be thriller then.. Although I've used the analog inserts from time to time with success and no bugs so I have some hope And I'm aware I'll have to manually write delay comp for the Prism interface, different for different sample rates so that's a bit inconvenient but I'll hopefully get into that

[albee1952]

If you really want to use multiple hardware devices, I would recommend you string them together and use them as a single insert within Pro Tools. This will avoid multiple D>A/A>D conversions and allow for a single Delay Compensation setting(assuming all analog in the external chain, the latency should not change regardless of how many pieces of hardware used). And, as always, I also would consider the need of the external hardware. Just because you CAN do something, doesn't always mean its the best route to the end product

[Unit7]

Originally Posted by albee1952

If you really want to use multiple hardware devices, I would recommend you string them together and use them as a single insert within Pro Tools. This will avoid multiple D>A/A>D conversions and allow for a single Delay Compensation setting(assuming all analog in the external chain, the latency should not change regardless of how many pieces of hardware used). And, as always, I also would consider the need of the external hardware. Just because you CAN do something, doesn't always mean its the best route to the end product

Thanks! Good input. The hardware I'd like to keep are coveted outboard that I've learned to use over the years and is a part of my workflow and my sound. I've done quite a lot of testing comparing hardware to plugins recently and sold off some pieces but there are like 40 pieces I don't want to get rid of and 20 of them I'd like to have hooked up to my interfaces for instant access. I'll string five units on the master bus, but the rest I want to keep open. That is, if I can get this to work fairly flawlessly..

[Unit7]

A little follow up, and I'm a bit embarrassed now.As I have the i/o's of my interfaces hooked up in patch bays it was very easy to try this, I just didn't think of it, because routing has been analog/console related for so long. Didn't have to insert the HW outboard even, I just (physically) patched the outs to the ins on the selected inserts. So I just took a stereomix and routed it the the way I described, took three minutes and it works! All three busses play in phase. Could perhaps run into delay comp issues when routing multichannel gets more complicated but now at least I know this is working.