Delay comp when overdubbing drums?

[crizdee]

Originally Posted by RKrizman

So that thread refers to checking the box in the I/O setup window that says "Compensate for input (or output) delay after recording pass."

I'm guessing that means that with ADC on (if you have plugins on previously recorded tracks), you'll be hearing tracks late and thus playing to them late. In that case, does checking that box cause your newly recorded track to be moved forward in time by the ADC amount, so that on playback the ADC will delay it (as it delays the other tracks) and it will be in sync with the other tracks?

If so, then you should overdub with ADC on and those boxes checked?

Not much explanation in the documentation.

-R

are you still referring to over-dubbing live drums?
Whats your routing for the tracks you are recording on to? as mentioned before if you have any auxes pre or post the audio tracks or any plugins in the monitor path the drummer will have trouble playing to the time delayed tracks.

Personally i always track with ADC off, but thats me and i use auxes as input channels with TDM plugs and bus tracks when recording etc.

[Media Man]

Originally Posted by crizdee

are you still referring to over-dubbing live drums?
Whats your routing for the tracks you are recording on to? as mentioned before if you have any auxes pre or post the audio tracks or any plugins in the monitor path the drummer will have trouble playing to the time delayed tracks.

I understand the plug-in latency ...if in the record/record monitor path, but how does using Aux tracks in the record/monitor path add to the latency ...or as someone suggested earlier in the thread, using outputs other than 1-2?

Mark

[peppertree]

I believe the HD delay compensator is basically broken...

What you should do in a specific situation is something you can determine yourself with pings. Mind the hidden checkboxes though...

[john a]

[QUOTE=peppertree;1413413]I believe the HD delay compensator is basically broken...

Yes, I agree, it is broken - I am at the mixing stage of a recent project, and the HD delay compensation has been a joke throughout. On the first tracking day, it somehow managed to record about six tracks out of twenty on the first tune in the wrong place. Dc was on when I started recording, and the headphone latency thing was happening - I turned it off, and we cut a very nice take- except when i played it back the overheads sounded like they had a 120 ms slap on them and the guitar was hopelessly out - which caused the guitar player to say " I can't hear this" and leave the control room -bit of a bummer. Shut down, blah blah blah- rest of the two days of tracking all fine.
I've gotten comfortable over time shifting tracks in PT to compensate for various delays, and basically ignoring others that don't have a perceptibly deleterious effect on timing. Today, I don't know why, I decided to turn DC on while doing a fairly involved rough mix of a complicated track for the same pproject. After about an hour or so things started to fall apart - guitar tracks arbitrarily shifted way out of time, bkgd vox and horns way late - I couldn't identify a clear culprit - had instantiated and removed a couple of large-delay-inducing RTAS plugs -but not on all of the affected tracks. Turned off DC, quit, shut down, retstarted and rebooted (client LOVED that I can tell you;-) ) and then nudged some tracks to compensate for delays, and it's all good. What is up with this tool? (yes I said tool) If it was actually smart enough to work it would be great - but how scary is it when all of the sudden you notice the kick has no bottom, the guitar solo is completely wack - -it's really just unworkable. And I'm really not a dummy about this stuff- I've done a lot of film mixing in PT, from 5.1.3 on, and there it really matters if you are xxx samples late because you can see that your sync is off - I've rigorously time shifted and catalogued the shifts on huge mixes like that - 60+ tracks -so I understand the process. How come I can't understand delay compensation? Peobably a case of RTFM. Hate that.

cheers

JA

[RKrizman]

Originally Posted by peppertree

We should request a ruling from the bench...

Yes, a little enlightenment from Digi would be nice.

-R

[crizdee]

Originally Posted by Media Man

I understand the plug-in latency ...if in the record/record monitor path, but how does using Aux tracks in the record/monitor path add to the latency ...or as someone suggested earlier in the thread, using outputs other than 1-2?

Mark

If you want to "record" with ADC on! then you must be recoding directly onto the tracks and have a direct monitor path with NO plugins inline to the stereo left and right outputs. this is the only way to achieve latency free monitoring with a TDM system. its not designed to allow for auxes anywhere in the chain to achieve total latency free monitoring whilst recording with ADC.

I TOTALLY don't recommend recording with ADC on! especially if recording live musicians who are playing in real-time against stuff that is being delay compensated. thats just MY personal opinion

If you must record with ADC on then select the boxes in the i/o setup page to compensate for input delays. this makes sure the audio lands at the correct place in the timeline. otherwise the playing just won't be in the pocket and you'll set yourself up for a nightmare of dragging audio around to try eliminate phasing and timing issues.

NOW! you can get away with small latency inducing TDM plugins (with or without ADC on) as the small amount of latency caused will probably go unnoticed by most musicians! though i have worked with keyboard players who notice down as low as 50-60 samples, but most will work ok with up to 100 samples.

This is just my view on things! alternatively you could listen to the wobbly heads who tell you its broken.

[peppertree]

Originally Posted by crizdee

If you want to "record" with ADC on! then you must be recoding directly onto the tracks and have a direct monitor path with NO plugins inline to the stereo left and right outputs. this is the only way to achieve latency free monitoring with a TDM system. its not designed to allow for auxes anywhere in the chain to achieve total latency free monitoring whilst recording with ADC.

I TOTALLY don't recommend recording with ADC on! especially if recording live musicians who are playing in real-time against stuff that is being delay compensated. thats just MY personal opinion

If you must record with ADC on then select the boxes in the i/o setup page to compensate for input delays. this makes sure the audio lands at the correct place in the timeline. otherwise the playing just won't be in the pocket and you'll set yourself up for a nightmare of dragging audio around to try eliminate phasing and timing issues.

NOW! you can get away with small latency inducing TDM plugins (with or without ADC on) as the small amount of latency caused will probably go unnoticed by most musicians! though i have worked with keyboard players who notice down as low as 50-60 samples, but most will work ok with up to 100 samples.

This is just my view on things! alternatively you could listen to the wobbly heads who tell you its broken.

That is broken, and my head isn't wobbly. I thought the whole point of TDM was to not have to worry about latency!

Even the manual is broken. And Rick, Digi isn't going to confirm their product is broken in a way they can't fix (due to the hardware limitations).

[zakco]

Originally Posted by crizdee

If you want to "record" with ADC on! then you must be recoding directly onto the tracks and have a direct monitor path with NO plugins inline to the stereo left and right outputs.

What about if the tracks you are recording are routed directly to physical outputs and everything else goes to an mains aux or master (with no plugins on the aux/mst)? Of course this requires a console, but some of us still have those...

-Z-

[RKrizman]

Originally Posted by crizdee

If you want to "record" with ADC on! then you must be recoding directly onto the tracks and have a direct monitor path with NO plugins inline to the stereo left and right outputs. this is the only way to achieve latency free monitoring with a TDM system. its not designed to allow for auxes anywhere in the chain to achieve total latency free monitoring whilst recording with ADC.

If you must record with ADC on then select the boxes in the i/o setup page to compensate for input delays. this makes sure the audio lands at the correct place in the timeline. otherwise the playing just won't be in the pocket and you'll set yourself up for a nightmare of dragging audio around to try eliminate phasing and timing issues.

First of all, I never use plugins or auxes or any latency inducing elements on the tracks that I'm recording. However, I may be overdubbing to a track that already has a lot of plugins (and latency) on the tracks that I'm trying to play in time to. So those tracks will be late. With ADC on, they will all be late the same amount, and therefore together. If I play to that, then my own new track will also be late, since I'm playing to those other tracks. So far, all is well, all is in synch. However, when I exit record, and play back the track I just recorded, still with ADC on, the ADC which had already been delaying the other tracks, will now delay my hitherto perfectly in synch track, making it late relative to the other tracks. Argh!

So the question is, what does clicking that little button do? What it NEEDS to do is take my newly recorded track and move it earlier in time by the amount of ADC that occured when it was being recorded. That way, on playback, when the ADC delays the new track, it will be again in synch with the other ADC delayed tracks.

Whew! If Pro Tools doesn't somehow do this, then it is indeed broken.

And we should all be forgiven our wobbly heads for trying to suss this out.

-R

[zakco]

OK, I've just done a careful test that proves that (at least for my workflow), tracking with ADC is not a problem.

This test does not include any midi or instrument channels - I'll test that another time.

For this test I'm using PT 7.4.2 and 10.4.11

1. create new session at 44.1 with buffer set to 512

2. create the following tracks: (All channels are routed to BUS 1-2)
-mono audio track with click sample on it as playback source
-mono audio track as record capture track.
-stereo aux input with TDM reverb (18 samples latency)
-stereo aux input with RTAS reverb (2100 samples)

3. create a mains stereo aux input with input set to BUS 1-2 and output set to OUT 1-2

4. I connected a handheld mic to input 1 (capture track) and bussed it to both reverb auxes using sends. No level was added to these sends, but the paths were active.

5. I held the mic up to my speaker's tweeters and recaptured the audio click track (muted of course ) to compare it with the source.

My results:

-With ADC ON and both compensate for delay boxes CHECKED in the i/o page, the recaptured audio was approx 88 samples late.

-With ADC ON and both compensate for delay boxes UNCHECKED in the i/o page, the recaptured audio was approx 176 samples late.

-With ADC OFF and both compensate for delay boxes CHECKED in the i/o page, the recaptured audio was approx 176 samples late.

-With ADC OFF and both compensate for delay boxes UNCHECKED in the i/o page, the recaptured audio was approx 176 samples late.

-Adding a 68 sample TDM plugin to the record input channel with ADC ON and boxes CHECKED made NO DIFFERENCE (88 samples late)

-Adding a 68 sample TDM plugin to the record input channel with ADC OFF made NO DIFFERENCE.

-Adding a 2300 sample RTAS plugin to the playback (click) channel made NO DIFFERENCE

-Routing and unrouting using sends to auxes made NO DIFFERENCE

-Changing buffer settings made NO DIFFERENCE

If somebody else could repeat this test, perhaps we can make a definitive statement in regards to tracking with ADC.