Delay Compensation and HW Buffer issues

[joeldadrummer]

I record drum tracks for people and I've been having some issues. I have Delay Compensation enabled, but if I put my headphones directly in front of my snare mics and record click only back into PT (either software or a printed click) it's always delayed by whatever samples my hardware buffer is set to (512 - 1024 etc). So basically whatever I'm recording is being printed 'late' and isn't tight, definitely noticeable on faster tempos and any jazz/fusion stuff.

Can anyone tell me why this is happening? Do I need to manually shift my drum tracks each time for playback/listening and bouncing?

I used to have a PTHD native rig (and don't recall this issue) but because of covid and the border still shut I can't access that computer, so I'm using a 2015 iMac with a Non-HD PT (ver 2020.3.0) set up with a thunderbolt apogee symphony MK2.

thanks,

Joel

[albee1952]

As far as I can figure, everything is working as expected. I would never attempt to track with a buffer setting higher than 64, and I ALWAYS make sure that there are no high-latency plugins active during any tracking.

There will always be a slight offset due to the buffer setting(why I keep it low) and conversion delay/latency(the time it takes for audio to come OUT thru the D>A converters, added to the time it takes to get audio back IN thru the A>D converters.

Re delay compensation, for those that are not highly technical, its important to remember that the compensation works by finding the track with the most latency, and then making all other tracks late to match(IOW, it never makes things earlier, it only pushes things later). Set your MIX window to show Delay Compensation and keep the total numbers(the bottom row) at 10 or less samples, and latency should not be an issue. Also, remember that latency on MASTER tracks is not compensated for, so don't pile on mastering plugins while tracking. Once tracking is done, you can set the buffer high to lessen strain on the computer.

When using a 3rd party interface, it may have its own software and buffer settings, and those would likely pile on top of whatever settings you have going in PT(this would not happen in your old HD/Native setup)

[joeldadrummer]

Interesting...I was under the impression that HW buffer was factored into Delay Compensation, otherwise every single overbdub needs to be shifted?

Also, I don't know how you track at 64 buffer? I can't track anything lower than 512 buffer, otherwise PT just crashes, even with no plugs. I was very surprised at this since I'm running a thunderbolt interface. So if I'm recording 16 tracks of drums or a whole band it's not worth the risk, and I have to use the apogee internal mixer to hear my drums in real time with whatever track I'm playing with, otherwise latency is unworkable.

With HD native yes I could track at 64 buffer fine.

I find this quite odd, but

[Darryl Ramm]

Originally Posted by joeldadrummer

Interesting...I was under the impression that HW buffer was factored into Delay Compensation, otherwise every single overbdub needs to be shifted?

Also, I don't know how you track at 64 buffer? I can't track anything lower than 512 buffer, otherwise PT just crashes, even with no plugs.

If you can't track at anything lower than 512 buffer then you are dead in the water... nothing compensates for that IO buffer latency while tracking.. time travel has not been invented. This is basic stuff for working with native systems (HD native or others).

And lets dispel the "even with no plugins" thing first. Plugins could well be relevant here, just because you have not instantiated plugins in a session does no mean they might not be causing problems. You need to properly check that plugins you have installed in Pro Tools are not causing problems. There must be thousands of posts about this on DUC. You should start with moving all plugins out of the plugin folder and trashing prefs and seeing what stability you get then.

Is the system *fully* optimized, every last thing done for now? Disk cache enabled (set to a size)? etc.

Pro Tools delay compensation feature only deals with plugin latency. Again your problem here is IO buffer size, which is real latency and cannot be magically compensated for. What is otherwise compensated for in Pro Tools varies. Pro Tools standard does not compensate for write latencies that HD/ultimate does. More discussion in the Pro Tools Reference Guide, but that's not the issue here, IO buffer size is.

[albee1952]

Indeed, assuming you are NOT running HDX, if your computer can't track at a 64 buffer, then your computer is either under-spec'd or has some big issues. When I had my commercial studio in Nashville, I ran an HP z820 with dual 3.5GHz 6-core XEON's and 64GB of RAM. Tracking was to spinning drives(C: was a Samsung SSD), running HD/Native card with 2xHD IO and 2x192 IO. I tracked 5-6 piece bands all day at a 64 buffer, with several dozen plugins in place and doing 6 stereo headphone mixes using sends in the sessions. Even my previous i7 6-core could handle that with the 32 live inputs(all the preamps I had).

[EGS]

Originally Posted by albee1952

...(all the preamps I had).

Ha!!! Good parenthetical comment. I've had people complain about input count limitations, only to realize they only have a handful of mics available!!!

[joeldadrummer]

Originally Posted by Darryl Ramm

If you can't track at anything lower than 512 buffer then you are dead in the water... nothing compensates for that IO buffer latency while tracking.. time travel has not been invented. This is basic stuff for working with native systems (HD native or others).

And lets dispel the "even with no plugins" thing first. Plugins could well be relevant here, just because you have not instantiated plugins in a session does no mean they might not be causing problems. You need to properly check that plugins you have installed in Pro Tools are not causing problems. There must be thousands of posts about this on DUC. You should start with moving all plugins out of the plugin folder and trashing prefs and seeing what stability you get then.

Is the system *fully* optimized, every last thing done for now? Disk cache enabled (set to a size)? etc.

Pro Tools delay compensation feature only deals with plugin latency. Again your problem here is IO buffer size, which is real latency and cannot be magically compensated for. What is otherwise compensated for in Pro Tools varies. Pro Tools standard does not compensate for write latencies that HD/ultimate does. More discussion in the Pro Tools Reference Guide, but that's not the issue here, IO buffer size is.

I'm no tech expert that's for sure, just a musician trying to record. I do trash prefs regularly using the PT helper app. No idea why my 2015 Imac under-performs, and I've no idea what 'fully optimized' specifically refers to. This is a dedicated audio computer, with the highest specs a 2015 retina iMac can be with a full SSD drive. All I know is I can't record at anything less than 512 buffer, and even then it risks crashing. I've heard the same from many musicians I know using Non-HD systems, so I was unaware that we were the exception?

I'm not expecting time travel, but I do expect 'delay compensation' to make sure tracks line up right, and write correctly (or shift audio) if there is a selected buffer delay. I have not read the entire manual, I guess I made assumptions that this was the case, and why wouldn't it be? Who in the recording business expects to manually shift every track or overdub they record at 1024?

[joeldadrummer]

Originally Posted by albee1952

Indeed, assuming you are NOT running HDX, if your computer can't track at a 64 buffer, then your computer is either under-spec'd or has some big issues. When I had my commercial studio in Nashville, I ran an HP z820 with dual 3.5GHz 6-core XEON's and 64GB of RAM. Tracking was to spinning drives(C: was a Samsung SSD), running HD/Native card with 2xHD IO and 2x192 IO. I tracked 5-6 piece bands all day at a 64 buffer, with several dozen plugins in place and doing 6 stereo headphone mixes using sends in the sessions. Even my previous i7 6-core could handle that with the 32 live inputs(all the preamps I had).

This is not an HD system. I've heard my drummer friends complain of the same issues as myself with their non-HD PT systems. Basically can't record at anything less than 512 buffer without PT crashing.
I wish I knew what was wrong or why this was the case, but since I know many with the same issue I figured it was just PT. I have a 2015 iMac dedicated to audio with 32GB of ram and an 4Ghz i7 processor, and 2tb SSD drive (upgraded) and use it with a Apogee symphony MK2 thunderbolt.

My previous experience using HD Native was not like the at all.

[Darryl Ramm]

Originally Posted by joeldadrummer

I'm no tech expert that's for sure, just a musician trying to record. I do trash prefs regularly using the PT helper app. No idea why my 2015 Imac under-performs, and I've no idea what 'fully optimized' specifically refers to. This is a dedicated audio computer, with the highest specs a 2015 retina iMac can be with a full SSD drive. All I know is I can't record at anything less than 512 buffer, and even then it risks crashing. I've heard the same from many musicians I know using Non-HD systems, so I was unaware that we were the exception?

I'm not expecting time travel, but I do expect 'delay compensation' to make sure tracks line up right, and write correctly (or shift audio) if there is a selected buffer delay. I have not read the entire manual, I guess I made assumptions that this was the case, and why wouldn't it be? Who in the recording business expects to manually shift every track or overdub they record at 1024?

Up the top of every DUC web page under "help us help you" is the optimization guide, also a part of the Pro Tools install documentation. Do every last thing.

Transiting through the IO buffer on any native system takes time. You have to think about what is going on. Latency compensation cannot move a signal back in time so you hear stuff time aligned while tracking. If you expect that you are expecting impossible time travel. [edit: oops sorry this was assuming you were comparing signals while monitoring, I realize I probably misnderstood your earlier posts? still you should be able to track at much lower IO buffer... and should still work out why not... and remember the "latency compensation" feature in Pro Tools is not a part of basic IO buffer compensation... that is part of the base system, or should be, but with some differences where HD corrects for additional latency]

That you have never had this issue before is lucky... if this same exact system with a different playback engine runs OK then that points at the interface/driver. Is that the case? Confirm you are running the latest driver versions and maybe contact the vendor support.

More generally you simply fix this by finding out why your system is not working as expected and unable to run at much smaller IO buffer size. This is not unusual to have to do, there are thousands of threads on DUC with folks dealing with this, I have given you lots of tips already, you have got to roll up your sleeves and do some work. Time to stop posting here and go do standard optimization and if needed troubleshooting steps. Like thousands before you, and if you get stuck or have questions then come back and ask and folks will try to help out.

[indeloon85]

Ha! I came on here for this very issue.

There is something up with PT lately and how it’s handling delay compensation/buffer issues.
For a long time I’ve ran an Apollo as my interface, and by doing so I would use UAD’s console to monitor and just have PT set to record the tracks. I would almost always run my buffer size at 1024 and NEVER had a problem with tracks being late on the grid (unless I played late). I would even run plug-ins in tandem or on the track I was recording to (obviously with the track muted) and it would still late the audio in correctly.
Now that is not the case. With the most recent version(s) (I’m currently running 2020.12) I need to run my buffer size super low to have it reflect closer to what I’m hearing in UAD’s Console.