Hi, folks. Maybe this is an old problem everybody but me knows about already, but here goes.

I've got an XP-80, and when I play a "thick" arrangement that is strictly quantized (to 16th notes), there seems to be a delay in the tempo between the 4th beat of the measure and the first beat of the following measure. I've tried moving the clock on some of the tracks forward and back a few ticks to spread it out, and that seems to help, but doesn't solve the problem.

Seems to me, what's the good of 64-note polyphony if you can't use it?

Anybody else seen this? If so, what did you do to fix it?

Thanks for your help!!

-Jer

Hi!

It is difficult to tell just what may be the cause of this, but I can tell you a little of what I have discovered..

Firstly; it does help to move the clock on the tracks, so that not all the MIDI-events happen on the same clock-beat. What is causing the probleem is obviously that the CPU or sound generator gets too much to do.

Could it be that you are using more than 64 tones? Remember that patches can use up to 4 TONES each. This means that all available polyphony will be used up when playing 16 NOTES.

Other thatn that, I think you should check what happens on the clock-beats, and try to move some of the events to other beats.

The last thing to check, is how much ControlChanges are going on. Some of these generate a lot of work for the sound generator, and make it slow down. A Data Thin could solve that.

Stig

Thanks for the response. It's possible that I could be getting close to maxing out the 64 voices, but I don't think I'm there yet because I don't hear any notes getting omitted or cut off. Typically, when the polyphony is maxed, the sustain on some notes gets abruptly cut off.

Anyway, I don't have a lot of controller information. No volume / pitch changes or anything like that. Just a few piano sustain pedals on/off's. No thick data.

Any other suggestions?

Thanks!!

-Jer

Anyway, I don't have a lot of controller information. No volume / pitch changes or anything like that. Just a few piano sustain pedals on/off's. No thick data.

Any other suggestions?

Thanks!!

what about aftertouch ?
that can clog up a system real good

Hi

Yes, the aftertouch generates a lot of data, and may also generate a lot of "work" for the synth.

When it comes to polyphony, you may be exceeding the limit without hearing it, if you dont exceed it too much. You have a page in the menu-system where you can see the fraa polyphony, and how much each channel uses.

I am running out of ideas here..

Stig

Oh, i remembered something that you wrote: quantizing. Thhis is probably the reason. Too many things happen at exact the same time, and this gives the synth too much to process, even if the polyphony is not exceeded. You really should try by switching off some tracks to hear what it does for the latency..

I am 99% sure that the quantizing causes the problem..

Stig

But if he's done some clock tick staggering this should no longer be an issue. My guess is unanticipated controllers such as aftertouch, or maybe not enough tick staggering.

Thanks for the replies, all. Here's what I did.

1.) I narrowed the latency problem down to one track that were causing about 60% of the problem. I went into the individual patches on those tracks and muted voices that were not critical to the mix, reducing the number of voices used for that patch from 3 to 2.

2.) Then, I staggered the tracks (shift clock) so that no two tracks triggered on the same tick of the beat, according to the strength of the attack for that patch.

Drums -- Bias = 0 (exact quantize)
Aux Percussion -- Bias = -1 tick
Bass -- Bias = +1 tick
Jazz Guitar -- Bias = -2 ticks
Steel Guitar -- Bias = +2 ticks (strong attack)
Pop Pad -- Bias = -4 ticks
Strings -- Bias = -6 ticks (slow attack)

That fixed the problem enough to where there was just BARELY a noticeable latency on the downbeat of 1. Joe Shmoe wouldn't notice...

Thanks alot for the advice!!

-Jer