Another Audio / MIDI Beat Clock: Input Delay

[pasthq]

Hi there,



I ran a kick drum through my setup into PT to sync it with a click track and realized that it's roughly 3200 samples to have it exactly going in sync.



I am using ProTools 12 as a master with my ATARI Cubase through an AMT8/Scarlett 18i20/Octopre and a few outboard synths/samplers.



The problem though then is that the recording is now coming early which makes me think that additionally to the MIDI delay, there is of course the roundtrip delay of the synths, ATARI, etc..Whenever I do a recording without the offset on the MIDI Beat Clock, the actual recording would show me roughly 2700 samples recorded too late but when I adjust that value I can hear the Kick Drum is not aligned anymore with the Click Track.


Judging from what I listen that gives me around 500 samples of unaccounted audio delay from the roundtrip that is not the soundcard. Where do I offset that? If I use the counter below the channel in mix window that only seems to account the delay after it's recorded but also I tried and it doesn't really do anything about it coming in later or earlier. Do I need to use the Time Adjuster for the Input Delay?



I had ignore errors unchecked and the audio is coming in at exactly the same point disregarding which buffer size is used. I can use 32/64 and higher of course.



Sorry for this maybe newbie question but I am used to Ableton where it seems very straight-forward for me.

[Darryl Ramm]

Can you please follow the DUC rules and keep all this in one thread? you've now spammed DUC with three different threads all related to the same stuff....

And you are maybe touching on stuff again that BScout already pointed out how to do if you want to use ADC +/- correction on a track you need to go though an AUX (something I should have pointed out).

[quote]
The problem though then is that the recording is now coming early which makes me think that additionally to the MIDI delay, there is of course the roundtrip delay of the synths, ATARI, etc..Whenever I do a recording without the offset on the MIDI Beat Clock, the actual recording would show me roughly 2700 samples recorded too late but when I adjust that value I can hear the Kick Drum is not aligned anymore with the Click Track.
[quote]

I cannot follow what you are saying. I'm lost how extra delay would make the signal appear early come early. If audio appears early it's because the actual latency is being over compensated for. And you are talking about 3200 and then 2700 samples. What is what?

You need to get the audio latency fully sorted out/understood first before dealing with MIDI. If you are measuring from what is recorded and you need to adjust an audio track to line stuff up (because for example you are coming in on an ADAT mic preamp with different input latency than the main interface). Otherwise you can just use the interfaces analog inputs and not need to worry about any auto input latency adjustments. (as explained before conversion, HW buffer, and misc. other overhead is always corrected in the recorded input signal, and does not require ADC to be enabled).

Are you aware of Pro Tools "Global MIDI Playback Offset"? What are *all* of your Pro Tools MIDI delay compensation settings?

ATARI ST Cubase? Really? You are triggering that to play back VIs? Or is it driving outboard MIDI boxes? Are the latencies there even consistent? There is no easier way to do want? Like just play out the MIDI notes from Pro Tools or ply a VI in Pro Tools? There are too many moving parts here. What happens when you get the more complex Atari out of the picture and just use the simplest possible MIDI device you have?

[pasthq]

[QUOTE=Darryl Ramm;2685038]Can you please follow the DUC rules and keep all this in one thread? you've now spammed DUC with three different threads all related to the same stuff....

And you are maybe touching on stuff again that BScout already pointed out how to do if you want to use ADC +/- correction on a track you need to go though an AUX (something I should have pointed out).

[quote]
The problem though then is that the recording is now coming early which makes me think that additionally to the MIDI delay, there is of course the roundtrip delay of the synths, ATARI, etc..Whenever I do a recording without the offset on the MIDI Beat Clock, the actual recording would show me roughly 2700 samples recorded too late but when I adjust that value I can hear the Kick Drum is not aligned anymore with the Click Track.

I cannot follow what you are saying. I'm lost how extra delay would make the signal appear early come early. If audio appears early it's because the actual latency is being over compensated for. And you are talking about 3200 and then 2700 samples. What is what?

You need to get the audio latency fully sorted out/understood first before dealing with MIDI. If you are measuring from what is recorded and you need to adjust an audio track to line stuff up (because for example you are coming in on an ADAT mic preamp with different input latency than the main interface). Otherwise you can just use the interfaces analog inputs and not need to worry about any auto input latency adjustments. (as explained before conversion, HW buffer, and misc. other overhead is always corrected in the recorded input signal, and does not require ADC to be enabled).

Are you aware of Pro Tools "Global MIDI Playback Offset"? What are *all* of your Pro Tools MIDI delay compensation settings?

ATARI ST Cubase? Really? You are triggering that to play back VIs? Or is it driving outboard MIDI boxes? Are the latencies there even consistent? There is no easier way to do want? Like just play out the MIDI notes from Pro Tools or ply a VI in Pro Tools? There are too many moving parts here. What happens when you get the more complex Atari out of the picture and just use the simplest possible MIDI device you have?

Hi there,



First of all sorry for not putting this into one topic. I am new here and was a bit confused about the structure of ProTools as opposed to other DAW.



I figured since I mainly record audio anyway right now with the same external sequencer (triggering only external gear) it's probably I should leave everything as it is and just have ProTools compensate what it automatically does anyway. It's pretty bang on grid.

[Darryl Ramm]

Hi

Sorry I'm still not following what is going on here, or even if you still have a problem. "it's bang on grid" when? You need to describe stuff like we are not there, have no clue what you are doing, and we are maybe not the brightest bulbs. I know it's painful to do.

I'm not really a MIDI person, I do understand audio latency stuff well. Other folks might have more of an idea. What I would do if this is my setup is to simplify the system as much as possible. Like I suggested say start with just triggering a click note from Pro Tools MIDI though an external synth and recording that audio in Pro Tools (either using the main audio input on the interface or on the ADAT Octopre once you know you have the audio latency adjusted for that correctly). With just that single synth understand it's expected latency, and the MIDI adjustments in Pro Tools. Then eventually try the external Atari sequencer and MIDI sync if you really want to use that.

[pasthq]

Originally Posted by Darryl Ramm

Hi

Sorry I'm still not following what is going on here, or even if you still have a problem. "it's bang on grid" when? You need to describe stuff like we are not there, have no clue what you are doing, and we are maybe not the brightest bulbs. I know it's painful to do.

I'm not really a MIDI person, I do understand audio latency stuff well. Other folks might have more of an idea. What I would do if this is my setup is to simplify the system as much as possible. Like I suggested say start with just triggering a click note from Pro Tools MIDI though an external synth and recording that audio in Pro Tools (either using the main audio input on the interface or on the ADAT Octopre once you know you have the audio latency adjusted for that correctly). With just that single synth understand it's expected latency, and the MIDI adjustments in Pro Tools. Then eventually try the external Atari sequencer and MIDI sync if you really want to use that.

Yes I understand the confusion, sorry about that.



I sent now the click plugin output from the 18i20 out back into the 18i20 and I had the signal roughly 60-70 samples early independent of buffer size (64,128,256). I guess it's overcompensating the audio in some way.