ADC with parallel bus problem (PT9)

[leebridges]

I searched, but couldn't find anything on this. This deals only with Pro Tools 9. I did not have this problem before 9.

I've reproduced this problem on both my HD Native system using a Digital 192 as an interface and removing the HD Native from the system and using an M-Audio Lightbridge.

I have a pretty complicated lead vocal chain. It involves multiple bus sends and hardware inserts. I'll do my best to simplify it to explain my ADC problem (worked perfectly before PT 9).

Audio Track (lead vocal) has an output of bus 2. The Audio Track also has a SEND that is sent to bus 1.

Aux Track 1 has an input of bus 1 and an output of bus 2. This Aux has a hardware insert on it.

Aux Track 2 has an input of bus 2. This aux track also has a hardware insert on it.

So, the Audio simultaneously goes out the send and the output. It goes through a hardware insert once from the send and then is rejoined with the original audio in the 2nd aux where it goes through a second hardware insert.

If I record the output of the second aux (which is a sum of the send-processed and non-send-processed sounds) I can see that the ADC over-compensates the SEND signal.

The signal that goes directly out the audio track's output and through just 1 hardware insert is correctly compensated. The signal that goes through the send (and 2 hardware sends) is overcompensated by exactly half of the hardware buffer size. If the hardware buffer size is 256, the audio ends up being 128 samples early. If the buffer is 512, then it's early by 256 samples.

If I put both hardware inserts on one track, and disable the send, everything lines up correctly, but this won't work for my setup.


Can anyone else duplicate this problem? Sorry if I've rambled too much. Please, ask questions if I've been confusing.

[leebridges]

bump.

I guess I either didn't explain it clearly or no one has this problem but me?

let me ask this, then, how do I officially report a bug to Avid?

[HD2]

From what I understand ADC is only compensation for software plugins. I don't think it has anything to do with hardware latency issues, however I could be wrong. I remember reading a post similar to this with the H/W buffer and latency of half the setting somewhere on here.

[formfunction]

Originally Posted by leebridges

I searched, but couldn't find anything on this. This deals only with Pro Tools 9. I did not have this problem before 9.

I've reproduced this problem on both my HD Native system using a Digital 192 as an interface and removing the HD Native from the system and using an M-Audio Lightbridge.

I have a pretty complicated lead vocal chain. It involves multiple bus sends and hardware inserts. I'll do my best to simplify it to explain my ADC problem (worked perfectly before PT 9).

Audio Track (lead vocal) has an output of bus 2. The Audio Track also has a SEND that is sent to bus 1.

Aux Track 1 has an input of bus 1 and an output of bus 2. This Aux has a hardware insert on it.

Aux Track 2 has an input of bus 2. This aux track also has a hardware insert on it.

So, the Audio simultaneously goes out the send and the output. It goes through a hardware insert once from the send and then is rejoined with the original audio in the 2nd aux where it goes through a second hardware insert.

If I record the output of the second aux (which is a sum of the send-processed and non-send-processed sounds) I can see that the ADC over-compensates the SEND signal.

The signal that goes directly out the audio track's output and through just 1 hardware insert is correctly compensated. The signal that goes through the send (and 2 hardware sends) is overcompensated by exactly half of the hardware buffer size. If the hardware buffer size is 256, the audio ends up being 128 samples early. If the buffer is 512, then it's early by 256 samples.

If I put both hardware inserts on one track, and disable the send, everything lines up correctly, but this won't work for my setup.


Can anyone else duplicate this problem? Sorry if I've rambled too much. Please, ask questions if I've been confusing.

It is confusing... but have you setup your hardware delay settings? Is your hardware digital or analog?
and I have noticed well before PT9 that mixing "around" auxes, while passing audio through them can be tricky at best. (how is that for confusing) ff