Automatic Latency Compensation & Plug Ins - Average? or Additive?

[WernerF]

ADC can, and should, be kept on at all times. It is designed to work correctly in a tracking scenario.

[gbross]

If it can and should be kept on at all times then why is it even an option to turn it off?

If it causes no harm to run - Avid should have made it transparent.

[Ant B]

I turn it off for tracking because I want all of my recordings to line up to the grid precisely, I'm assuming if it's on (never tried tracking with it on so perhaps I'm wrong) then there is the offset created by the delay.

If I'm right, though - I wouldn't want a whole session delayed by a few thousand milliseconds just because at some point I might do the final mix myself. If I'm wrong - then none of this matters, of course.

[Stig Eliassen]

Originally Posted by gbross

If it can and should be kept on at all times then why is it even an option to turn it off?

If it causes no harm to run - Avid should have made it transparent.

There are quite a few things in PT that causes no harm to run, but we still have the option to turn it off. In version 7 and 8 there's a MIDI bug that affects the timing of recorded MIDI if ADC is on during tracking, so I'm very thankful I can disable it whenever I want. I'm still on 7.4.2. I hear this is fixed now.

ADC gets disabled automatically the second you record-enable a track. Check for yourself - the ADC numbers are right below the track name in the Mix window, if you have it visible.

Also, check that the Compensate for input/output delays after record pass options are enabled. These takes care of the converter latency.

[Ant B]

Originally Posted by PT Lover

ADC gets disabled automatically the second you record-enable a track. Check for yourself - the ADC numbers are right below the track name in the Mix window, if you have it visible.

I did not know this - but that's great to know. I guess that brings up a different question then..

What's the purpose of recording with ADC on (other than efficiency/not having to enable it later) if it shuts off while recording? Using a plugin with a lot of delay on other tracks in the mix will throw performance timing off if the ADC that was previously applied is taken off for a pass on a new track - or does it just do this for the record enabled track?

[WernerF]

The ADC get's temporarily turned off on the input track. Every other track and plugin are still being compensated for. ADC then compensates for your newly recorded track after your record pass. That way, the sound of your mix is consistent between tracking and mixing.

[Ant B]

Originally Posted by WernerF

The ADC get's temporarily turned off on the input track. Every other track and plugin are still being compensated for. ADC then compensates for your newly recorded track after your record pass. That way, the sound of your mix is consistent between tracking and mixing.

Thanks for the reply - just to make sure I understand completely what you're saying:

If I have ADC set to 4095 and record a perfectly timed (and bland) track once I'm done recording protools shifts the newly recorded audio by 4095 to bring it back to "0" and applies ADC to the track matching the rest of the session like normal?

[Stig Eliassen]

Originally Posted by Ant B

Thanks for the reply - just to make sure I understand completely what you're saying:

If I have ADC set to 4095 and record a perfectly timed (and bland) track once I'm done recording protools shifts the newly recorded audio by 4095 to bring it back to "0" and applies ADC to the track matching the rest of the session like normal?

PT knows that you're listening to a delay-compensated mix when recording with ADC enabled, and does the math for you. 4095 is just the number of samples PT allocates to the ADC engine for each track, which is the limit for the Long setting.

[Ant B]

I guess I'll have to do a test myself when I get home.

What I'm asking is does protools physically move the recorded audio to 0, or does it record at the delay offset and stay there.

If I record a kick snare, add compression and EQ to the kick and snare with a plug that gives me a little delay, enable ADC - everything is lined up. If I then record a bassline the recording is compensated yes - but if I turn off ADC, strip the plugin off of the kick and snare - everything should still line up and have the same groove. That's my concern.

**edit**

and then the other question to this would be...

Since protools disables ADC on the record armed track if every other track in the session is playing with ADC on and I'm doing a punch in on audio recorded on ...the record armed track - won't that track that I'm punching in on be playing back out of sync with the rest of the session?

[Stig Eliassen]

Originally Posted by Ant B

I guess I'll have to do a test myself when I get home.

What I'm asking is does protools physically move the recorded audio to 0, or does it record at the delay offset and stay there.

If I record a kick snare, add compression and EQ to the kick and snare with a plug that gives me a little delay, enable ADC - everything is lined up. If I then record a bassline the recording is compensated yes - but if I turn off ADC, strip the plugin off of the kick and snare - everything should still line up and have the same groove. That's my concern.

Yes, you should definitely check out ADC for yourself.

PT places the recording where it should be. If you play/sing/whatever smack on the grid, PT will place it smack on the grid. If PT were to place the audio with any delay offset, the recording wouldn't visually match what you hear, which would be totally confusing.

Look, I've been through this myself, wondering how ADC works. The fact is that it just works, and I keep it on at all times, except for when I'm recording MIDI in PT 7.4.2. This is a known bug, and from what I've heard, it's fixed in PT 9 and 10.