Sudden Volume Changes

[kinnylandrum]

Tracks which don't belong (either muted, or even maybe from a different chunk) seem to cut in. In some cases, it may be an Aux that is doubling the entire mix -- such as an Aux I set up for reverb, but which I'm not using. Maybe it comes in for a few bars and doubles the mix, raising the volume in the process.

You know, now that I think about this, my problems may ONLY be happening when using Aux tracks. I normally only use Aux tracks when returning Drumcore to my mixes via Rewire. I could blame Rewire, but now that I think about it, when I don't use Aux tracks I don't think I've experienced problems. On the other hand, today when working with drums a lot today, I got surges fairly frequently, most it seems when in record on a MIDI track (not necessarily Drumcore). But when doing some projects recently that did not involve drums, and therefore probably not Aux tracks,
I don't remember any problems. Shooshie, you may be onto something here with Aux tracks. And I have not been having any of the phasing problems, although I had that in the distant past (under DP 4.x)

[MIDI Life Crisis]

No AUX tracks in my case. I use 'em, but not that often.

[Tomas E]

c) Audio Playback is fine.

Thank God for that! I haven't tried recording the MIDI yet.

[Rick Averill]

I don't have anything to add to this thread, as everything I've experienced has been logged by others more expert than I. But I am following it very closely, because when an answer is found, I am anxious to learn about it. These things are very annoying, as you all know. And if I do come across anything else that hasn't been reported, I'll post it. But thanks to all of you for continuing to investigate this.

[monkey man]

I would like to know if anyone who experiences surges has experimented with Aggregate Devices in Apple's Audio/MIDI Setup app.Shooshie

Never done this here either.

If you (or anyone else) is able to make a database of our various relevant (we hope) details, Shoosh, much as you did earlier, I get the feeling we'd likely make progress.
The only caveat would be that MOTU may have already implemented a fix for this in the next DP.

[Rick Averill]

I think I just experienced something very interesting regarding the mysterious volume surges. I don't know if this is a clue or not. It may be related to something else entirely, but I had an instance where it was happening about 90% of the time when I hit play. I can see it as though it was just this afternoon. (Cue whole-tone glisses in harp) Oh wait--it was just this afternoon.

I was wanting a little more fullness in my tremolo strings. I was using GPO keyswitch (KS) instruments for the strings, separate samples for violin 1, violin 2, viola, cello, and bass. So I instantiated a new voice, the full KS string section, and doubled all my tremolo string parts in it. When I hit play I got a volume surge just on that track about 90% of the time. The other 10% it played just fine. It didn't matter where I had my volume (CC7) or mod wheel (CC1) set, the track still blasted out. So I went back to the instrument track and changed the sample to another KS cello voice. It still surged. This one track, this one MIDI channel on this one instrument track. Even after I shut down and restarted the computer (which for me seems to minimize the surges) it still behaved the same. Then I went back and changed it to an entirely different sample library--the MSI strings--and the problem was gone.

As Artie Johnson would say, "Very interesting. Not very good, but very interesting." Okay--forgive me the Laugh-In reference.

Now I'm not sayin' this is the same problem and I'm not sayin' it ain't. But it is the first time I have consistently gotten a volume surge and have been able to tie it to anything specific. It may be a piece of the puzzle, or maybe not.

[Frodo]

Rick- what you've discovered fits into the quirk's descriptions very nicely. The copy/paste theory is but one variation. Your theory of duplicating certain types tracks with samples from the same library appears indeed to be another piece to the puzzle. The most remarkable thing from my view is the fact that you can nearly induce it repeatedly. This is significant.

What stumps me on this end is that I could be bopping along just fine all morning and then without adding any additional samples the surges start.

It's clearly related to memory usage and how file/sample references are stored and recalled.

Trashing MAS Preferences is not the solution because the source of the problem rests with the way MAS deals with Core Audio and/or the other way around. Just as soon as you think you've got it nicked it starts up again.

My most recent experience sort of defeats my other theory of this happening with more than 32 threads going in each app. Yesterday, I had surges with DP showing only 22 threads running.

In my book, this easily ranks as the #1 DP enigma of the century to date.

[Rick Averill]

It's clearly related to memory usage and how file/sample references are stored and recalled.

If they get too bad, I can usually minimize them by quitting DP and restarting the computer. This, however did not seem to be case in the situation I described above.

[monkey man]

Just this last weekend they came back for me again.

Man, just when I thought they were finally a thing of the past...
I've installed nothing and done nothing different, although I did have to hard-restart after a kernel panic having only just turned the machine on and connected to the 'net (5-10 secs).
No idea why that happened.

FWIW, it's not as bad as previously; quite rare in fact.

[Shooshie]

I've found that when you talk about them, they appear. It's best to make yourself believe they don't exist. Then they feel slighted and leave in a huff. Theoretically, anyway. Apparently I've never been able to fully convince myself that they don't exist. There is always a little bit of doubt, and so they come back.

Shoosh

[monkey man]

Aah... sceptic's syndrome, eh Shoosh?

[Tomas E]

First I would like to change the terminology from "sudden" to "unwanted". Because often the sudden volume changes are wanted. Don't you agree?

This is my theory so far regarding unwanted volume changes in VI's.
When a patch change is initiated, the VI patch loaded comes with a certain volume preset. This volume preset must be changed if it doesn't correspond to the desired value. Therefore you have to add an additional controller #7 message after the patch change, since the patch change seems to be treated as if you would disconnect the MIDI cable of your hardware synth and plug it into another one. Alternatively DP must be told to reinitiate an event chasing after every program change to get the correct values for the new patch. As far as I know event chasing only occurs when hitting play, and is not a continous kind of feature that would work when switching cables on the fly. Or is it? If so my theory fails.

To try this I saw to that the patch changes in the tracks where the unwanted volume changes occured, were placed at the same measure, beat and tick 5|4|240. In this case it was the best thing to do since all the instruments had a brief rest. And finally I took a volume snapshot - from counter to next change (flat) - at 5|4|300 of the tracks in question.

The test
- I chained the chunks.
- I started playback towards the end of the chunk before.
- There were no unwanted volume changes.
- I undid the snapshot and tried again.
- This time the unwanted volume changes reappeared exactly as before in the same tracks.
- I redid the snapshot.
- There were no unwanted volume changes.

Whatever is the cause, this method is a workaround. But I can't say I like having to make workarounds. Since I'm a Mac fan I've always had the idea this only applies to PC users.

[Shooshie]

You are correct about event chasing. It only happens when you hit play. There should be something incorporated in patch changes that causes a new event chasing for controllers and notes.

However, this isn't the only kind of sudden volume change. The ones I've experienced were not associated with patch changes, because I don't use patch changes in my tracks. I use a separate track for different instruments, so that I never have to use patch changes.

The volume changes are pretty rare these days.

Shooshie

[MIDI Life Crisis]

You are correct about event chasing. It only happens when you hit play. There should be something incorporated in patch changes that causes a new event chasing for controllers and notes.

However, this isn't the only kind of sudden volume change. The ones I've experienced were not associated with patch changes, because I don't use patch changes in my tracks. I use a separate track for different instruments, so that I never have to use patch changes.

The volume changes are pretty rare these days.

Shooshie

Same here. No patch changes. Each voice gets a track. Volume changes are a thing of the past for me.

[dfeinman]

I have followed this lively thread with interest and dread, as I have been tormented by the dreaded surges ever since I began using virtual instruments on a Dual G5, approximately 3 years ago. I have tried EVERYTHING there is to try and nothing helps. And MOTU tech support seems to have grown weary of this complaint. I have been a DP user since the release of version 1, but this enigma is too problematic for customer loyalty to be of much significance. The random level surges have rendered the software simply un-useable. Do I here Digidesign calling?