I Learned Something About DP Timing Today

[HCMarkus]

When one changes the buffer size, one must de-select Record Enable, then re-enable in order to preserve timing of audio that being recorded.

I was able to prove this by looping back audio. I was doing a little timing testing to satisfy myself that DP was accurately recording my input. When I started switching buffer sizes, I started getting irregular results... sometimes audio was spot-on, other times not even close to its source.

I started working with DP's Metronome and got similar results. Although the Metronome was sounding (phasing) in-time with a pre-recorded, perfectly on-beat Metronome track, the recording was placed in the timeline early or late, depending on where I set the buffer.

Then I stumbled on the answer: DP apparently recalibrate itself internally when one record-enables a track. All I had to do to get perfect, in-time recordings after changing the buffer size was to disable the track Record Enable, then enable it again. Perfect.

Moral of the story: Don't go changing (thank you Billy Joel) your buffer without first disabling recording on tracks. Re-enable recording after changing the buffer size.

I don't have time to test MIDI right now. Anybody want to try that out?

Also, we should test whether disabling/re-enabling recording on one track will reset timing for other record-enabled tracks. I'll try to get back to this later, but invite others to confirm/enhance my findings.

[mikehalloran]

That explains a few anomalies that I've encountered lately.

I never record enable before changing the buffer — except on rare occasions when I forget. When the latency happens, I shrug my shoulders, save, close and reopen the project and the issue goes away upon reopening.

I've never made the connection but I'm betting it's exactly what you say.

I'll be able to test this in a day or two.

[MIDI Life Crisis]

I rarely change my buffer, but I rarely record live into DP these days. Good to know! Thanks.

Buffy approves... or not.

[Frodo]

Wow. Hooda thunk it?

Thanks, HC!

[HCMarkus]

You're welcome gents!

Always especially nice to see the furry-footed one 'round these parts. Not so sure about Buffy.

[labman]

Thank you Markus! I did not know that. Extra dessert for you today!!!

[bayswater]

That's great detective work. Do you suppose MOTU knows about this? I guess they "know" but its something that should at least be mentioned in the manual and on the web site.

[stubbsonic]

That is incredibly useful to know. Seems like the easy fix is for MOTU to add a little pop-up window.

"You've just changed the buffer size. Disarm and re-arm record on all tracks for change to take effect."

[MIDI Life Crisis]

Or automatically disarm and rearm to reset it every time?

[HCMarkus]

Thanks all! I sent an advisory TechLink to MOTU with your suggestions.

[monkey man]

Always especially nice to see the furry-footed one 'round these parts. Not so sure about Buffy.

You talkin' 'bout RugRunner (Frodo) or moi, Sir Markus?

Or automatically disarm and rearm to reset it every time?

It shouldn't be a matter of DP's disabling then re-enabling anything IMHO, Magilla - it only need refill the current buffers. Done. In-theory.

[HCMarkus]

Always especially nice to see the furry-footed one 'round these parts. Not so sure about Buffy.

You talkin' 'bout RugRunner (Frodo) or moi, Sir Markus?

Both of you, of course! You are our prime(ate) number here, MM.

[monkey man]

Awesome! What a compliment, Sir Markus. Thank you.

Love prime numbers.

[waterstrum]

I tip my hat to HCM.

I frequently change buffer settings during sessions.
I've wondered about the occasional off timings.
Great solution!

Thanks for figuring it out!

[monkey man]

Yeah, he's really-on-the-ball, our Sir Markus.