Buffer latency compensation problem, Mackie Onyx 1640i, PT11 native

[WinTaper]

There are hundreds of threads on this issue.

The short answer is that ADC works for plugins and devices that report their latency back to Pro-Tools. 3rd party interfaces DO NOT.

Since you are looping DA->AD what you are seeing is a hardware buffer inside your interface/converters that pro tools has no way of knowing about.

You can measure the offset and then manually add it in at the bottom of each track in Mixer View.

HD interfaces talk back to Pro Tools and eliminate this problem. Avid could add a simple "hardware offset" feature similar to Sonar and Cubase - but so far they have not.

-Dan

[Wall2Wall]

Originally Posted by WinTaper

The short answer is that ADC works for plugins and devices that report their latency back to Pro-Tools. 3rd party interfaces DO NOT.

Since you are looping DA->AD what you are seeing is a hardware buffer inside your interface/converters that pro tools has no way of knowing about.

You can measure the offset and then manually add it in at the bottom of each track in Mixer View.

Add in, being that it's a firewire connection, the latency will change by a few samples every single time there is a reboot.

[WinTaper]

Originally Posted by Wall2Wall

Add in, being that it's a firewire connection, the latency will change by a few samples every single time there is a reboot.

No that shouldn't happen. We are talking about a hardware buffer in the ADC. Pro Tools should compensate for firewire latency on-the-fly.

Also, this offset that we see from looping an output back to an input should be fixed because the hardware buffer size is (obviously) fixed. The offset would be the same number of samples regardless of PT's playback buffer. On my RME RayDAT / SSL system its 88 samples - regardless of PT playback buffer size.

[Amack]

For all of my devices Pro Tools does know! When I set buffer sizes using the ASIO device's control panel before starting Pro Tools, it's properly reflected in the Pro Tools "Playback Devices" "H/W Buffer" size. Also, apparently the only way to change the ASIO buffer size while Pro Tools is running is to use Pro Tool's control panel for the device.

Originally Posted by WinTaper

There are hundreds of threads on this issue.

The short answer is that ADC works for plugins and devices that report their latency back to Pro-Tools. 3rd party interfaces DO NOT.

Since you are looping DA->AD what you are seeing is a hardware buffer inside your interface/converters that pro tools has no way of knowing about.

You can measure the offset and then manually add it in at the bottom of each track in Mixer View.

HD interfaces talk back to Pro Tools and eliminate this problem. Avid could add a simple "hardware offset" feature similar to Sonar and Cubase - but so far they have not.

-Dan

[Amack]

I thought we were talking about the ASIO driver's buffers in the computer that are intended to ensure that the software and data can keep up with the data flow! 88 samples of hardware D-A + A-D delay sounds very excessive!

But. this is based on my understanding of
http://www.soundonsound.com/sos/jan0...pcmusician.htm (which seems consistent with other info that I was able to find online).

Originally Posted by WinTaper

No that shouldn't happen. We are talking about a hardware buffer in the ADC. Pro Tools should compensate for firewire latency on-the-fly.

Also, this offset that we see from looping an output back to an input should be fixed because the hardware buffer size is (obviously) fixed. The offset would be the same number of samples regardless of PT's playback buffer. On my RME RayDAT / SSL system its 88 samples - regardless of PT playback buffer size.

[Amack]

It looks like Darryl was right about Pro Tools attempting to correct for ASIO audio interface device latency, with ADC either ON or OFF. Whether it's successful or not appears to be device dependent. As shown in the attachment, it's highly successful with Roland's Studio Capture operating at 192 kHz sample rate with a bit depth of 24 bits. When ADC is ON the "System Delay" shown in System Setup appears to be the correction applied (i.e. the net latency).

June 2, 2015 Update. I've since learned that Pro Tools' "System Delay" is the ASIO device's reported output latency minus the "Buffer Size" (reported in "Playback Engine").

[Darryl Ramm]

Besides just taking over somebody else's thread I, and I suspect others here, am not sure what you are posting here or why. You don't clearly explain what you are doing, how things are measured etc. maybe you should start a new thread and explain what you are trying to do.

[Amack]

Darryl,

I've been posting to this thread in an effort to show that Pro Tools may be the cause of the problems reported in the 1st and several following posts. I say this because I've determined that other ASIO audio devices exhibit the same problem. I've tried hard to explain how the measurements were made both on the thread (earlier) and in the attachments (earlier and later). Did you look at the attachments? I'm sorry if you think that I'm not being clear enough - but I'm not sure what else I can do to explain it! Is everyone else so confused?

Did you (and/or others) understand the setup and results in the 1st post? How did that differ from what I've posted?

Amack

Originally Posted by Darryl Ramm

Besides just taking over somebody else's thread I, and I suspect others here, am not sure what you are posting here or why. You don't clearly explain what you are doing, how things are measured etc. maybe you should start a new thread and explain what you are trying to do.

[Amack]

Darryl,

When you learn of bugs/inadequacies in Pro Tools, do you notify appropriate people at Avid to get them properly addressed/corrected? If not, how does one go about doing so?

Respectfully,
Amack

Originally Posted by Darryl Ramm

Besides just taking over somebody else's thread I, and I suspect others here, am not sure what you are posting here or why. You don't clearly explain what you are doing, how things are measured etc. maybe you should start a new thread and explain what you are trying to do.

[Amack]

It sounds like the Mackie Onyx 1640i is one of those (apparently all too many) ASIO interfaces that don't report their I/O latencies properly. My experience is that the interfaces for which PT's "System Delay" doesn't increase with "H/W Buffer Size" don't. But the only way to know for sure is to measure it. That's easy to do - see http://duc.avid.com/showthread.php?t=368814

Originally Posted by Wirtanen

Hi all!

I've been reading through this and other forums for the past couple days, but can't seem to find a cause for the exact problem I'm having. Lots of long threads about problems with h/w inserts and adc though. Long story short:

When we're recording audio, Pro Tools does not automatically compensate for the input delay. Buffer size directly affects how late the audio is placed on the timeline. Here's a screenshot to elaborate:

Attachment 3697
EDIT: Here in hi-res: https://flic.kr/p/rB7SSz

Routing: SOURCE out to Mackie -> from physical output to an input with a cable -> input recorded to Rec_***-tracks with corresponding buffer sizes. SOURCE-track is an internally routed and printed click track.

Tested with:
Fresh booted pc without any extra software running
Fresh session without a template
Delay compensation on and off
Mackie firewire drivers v1.7 and v1.9

What I've learned from other threads, is that Pro Tools is apparently supposed to compensate for this kind of delay automatically (even non-HD), IF the 3rd party device is reporting ASIO latency correctly. DigiTechSupt said this, but can't find the thread anymore to quote, sorry. So I'm starting to suspect if this is Mackie's fault...?

Funny thing is (very funny) that we've been tracking our album for 1½ years now, and only just noticed this now. Acoustic drums were recorded first, then guitars over the drums, and so on. Buffer sizes were small at the beginning, so the delays were small and went unnoticed. 10 song session has grown and got plugins along the way and all, and buffersize has been increased. So, now when we're doing some small fix recordings etc., I have to manually nudge the recorded tracks back. I'm just wondering how much tighter the playing would sound without the small delays on the guitars, basses and vocals.... But I guess I have some careful listening & nudging to do.

Anyhow, are there any Onyx i-series users here? Have you experienced anything similar? Or any other ideas what might cause this? I also sent a mail to Mackie's techsupport asking if they know something about this (earlier today, so no response yet). Can you think of any other test scenarios I could try to narrow down the cause?

Any help or insight would be much appreciated! We jumped to PT when 11 was released, so still in learning.