fundamental pro tools latency question.

[smallanimalsounds]

so i've been using the same HD2 system for over a year, and never noticed and/or had this issue...
i'm in the middle of a week long project with a new client who brought in some session files recorded elsewhere. we've been tracking overdubs and have noticed a bizarre timing issue: the tracks that we have recorded are being played back LATE in relationship to the rest of the session. we thought we were just imagining things and that he was actually performing late, but this has been happening with every overdub. this isn't a playback engine issue, right? i mean, it's understandable that the music being currently recorded is being heard a bit late in the headphones... but late during playback? how can this be? is there something in the preferences that could be adjusting the way pro tools takes live material and puts it in time? some kind of parameter deeply hidden in the bowels of HD? like an insert delay compensation or something with the I/O's? The weird things is that when we tried nudging things to line up, it didn't really sound correct until we moved it 1024 samples . we tried running at both 256 and 512. and strangely the buffer option for 128 was not even an option in the drop down menu. this is definitely an option in other sessions. what is up?

we're running a Furman HDS6 headphone system, if that helps.
thanks

[JGriffin]

Got any plugins on those tracks?

[ott0bot]

was the original session recorded with a different sample rate than your HD session?

It may be easier to start a new session then import them into a newly created hd session...then disable all plug ins while recording. Man I really haven't had too many latency issues with an HD system. It can usualy handle most plug ins i've used without latency.

Could be the buffer or hardware settings are different on the LE session too.

[joel hamilton]

so i've been using the same HD2 system for over a year, and never noticed and/or had this issue...
i'm in the middle of a week long project with a new client who brought in some session files recorded elsewhere. we've been tracking overdubs and have noticed a bizarre timing issue: the tracks that we have recorded are being played back LATE in relationship to the rest of the session. we thought we were just imagining things and that he was actually performing late, but this has been happening with every overdub. this isn't a playback engine issue, right? i mean, it's understandable that the music being currently recorded is being heard a bit late in the headphones... but late during playback? how can this be? is there something in the preferences that could be adjusting the way pro tools takes live material and puts it in time? some kind of parameter deeply hidden in the bowels of HD? like an insert delay compensation or something with the I/O's? The weird things is that when we tried nudging things to line up, it didn't really sound correct until we moved it 1024 samples . we tried running at both 256 and 512. and strangely the buffer option for 128 was not even an option in the drop down menu. this is definitely an option in other sessions. what is up?

we're running a Furman HDS6 headphone system, if that helps.
thanks

If you have delay compensation on during the overdub, it will mess with your input monitoring.
Turn it off by toggling in the options menu.
you dont have to go back to the plyback engine every time.
Just turn it off in the pulldown menu.
Try it both ways. I would bet money it is that.
The same thing happens when you are tracking a midi part with delay compensation on. it feels incredibly screwy, and the feel gets messed up like crazy. the note "lands late."
Oh, and this is being moved to COMPUTER WORLD.
Thanks.

[Nick Sevilla]

I have HD2.

Digidesign recommends you TURN OFF delay compensation until you are doing final mixing.

Cheers

[btswire]

Digidesign recommends you TURN OFF delay compensation until you are doing final mixing.

Hmm, I find that a bit odd. Say that you have a percussion track with some plug ins that introduce a 4000 sample latency. This would be equal to about a tenth of a second at 44.1K. Then you go to overdub a guitar track. If delay compensation is turned off, you will be hearing the percussion a tenth of a second late, so your guitar playing will also be a tenth of a second late, correct?

[Nick Sevilla]

Digidesign recommends you TURN OFF delay compensation until you are doing final mixing.

Hmm, I find that a bit odd. Say that you have a percussion track with some plug ins that introduce a 4000 sample latency. This would be equal to about a tenth of a second at 44.1K. Then you go to overdub a guitar track. If delay compensation is turned off, you will be hearing the percussion a tenth of a second late, so your guitar playing will also be a tenth of a second late, correct?

Yes.

I try not to use RTAS plugins while tracking, and keep plugins to a minimum, using hardware when possible. Those are the worst, in term of latency.

I also found that if you turn on the DPC at the very start of your session (nothing being recorded previously) then you can see how your newly recorded audio gets moved forward (to the left) and plays back too early..

Again, they recommend not using PDC until mix time.... maybe their papers are outdated... but I have not found that using PDC during tracking is a good thing.

Cheers

[btswire]

This seems to me like a HUGE Pro Tools limitation, perhaps bigger than any other that people are always moaning about on this forum. I would imagine that most of us mixing in the box are using many RTAS plug ins, and that as we proceed forward with overdubs we also do some mixing. To stop using RTAS plug ins until the final mix stage would completely chnage the way we work. It's hard for me to even imagine.

That being said, I do very little tracking in Pro Tools, so I'm curious to hear input (no pun intended) from those of you who do this work all the time. Do you simply have a ton of DSP cards and rely on TDM plug ins? Any suggestions for the guy who just invested 8 grand in a HD 1 rig? Should we forget about automatic delay compensation in Pro Tools entirely and just use MellowMuse instead?

[Nick Sevilla]

This seems to me like a HUGE Pro Tools limitation, perhaps bigger than any other that people are always moaning about on this forum. I would imagine that most of us mixing in the box are using many RTAS plug ins, and that as we proceed forward with overdubs we also do some mixing. To stop using RTAS plug ins until the final mix stage would completely chnage the way we work. It's hard for me to even imagine.

That being said, I do very little tracking in Pro Tools, so I'm curious to hear input (no pun intended) from those of you who do this work all the time. Do you simply have a ton of DSP cards and rely on TDM plug ins? Any suggestions for the guy who just invested 8 grand in a HD 1 rig? Should we forget about automatic delay compensation in Pro Tools entirely and just use MellowMuse instead?

I have two of the new HD TDM card (Accel). They have 18 DSP chips each. And using TDM it does not induce too much delay while tracking, usually a few samples (7 to 24, for example)

Digidesign simply recommends you turn on PDC afterwards, when you will no longer record, so that tracks remain aligned once ProTools starts the compensation calculations.

If you record with it off, and then mid-session you turn it on, you will get imroperly delayed new recordings.

I find that 24 samples of delay is not enough to annoy a musician, nor myself. This is at 24 bits 48 kHz sampling rate.

Cheers