ForumsHardware ← FIXED: "Zippering" in Silent Way

There's been this scratchy sound going on when I've been playing - until yesterday I had chalked it up to noisy patches, and a janky VCA. Then I started a mellow-sounding patch and realized my VCAs are fine - what is happening is I'm getting data "zippering" sending OSC through Silent Way and the Expert Sleepers ES-3 module.

It's most apparent in the Z control but is happening with all continuous controls (x, y, z).

At high data rates (OSC rate control in the Client set at 500, or maximum) it sounds like that bad-jack or scratchy-pot kind of sound. At low data rate (OSC rate control at 14, or minimum) it does this rhythmic Alva Noto glitch thing - which is cool but not what I want normally. I will record/post audio examples if need be.

One thing that helps is turning the Lopass control in the Soundplane Client to its minimum, or "1" (no other Lopass setting is effective, not even "2"). But the Soundplane is pretty much unplayable at that setting. I couldn't find any other controls in the Client or in the Silent Way plugs that had any effect (for example "smoothing" in the SW Soundplane plugin had no audible effect).

Is this something that a higher OSC send rate would fix? I wonder if I'm doing something wrong. I will also holler at Andrew Ostler today and see what he thinks.

Well, OSC doesn't send signals, just a series of messages, so any reconstruction of a signal, as would be needed to avoid zippering, is going to be up to the receiver.In other words, Expert Sleepers needs some kind of filtering there, and I would be surprised if it didn't have it already. I would ask Andrew about how to filter the data.

I would shoot for data rates of maybe 50 Hz with this kind of setup. The initial "note-on" (or in the case of OSC, first message for a touch) is always sent ASAP, so you are not adding latency. It’s just the frequency of control messages after that that is affected, and you can't really generate more than 50 Hz of bandwidth by moving your fingers around anyway. The higher rates are just in case they are needed for some application I wasn't considering...

Update: Talked to Andrew, who advised me to inspect the signals on a scope. I did this, and am seeing a jagged/stepped sine kind of waveform.

He told me to use the "Smooth" control in the Soundplane plugin - but this has no effect at any setting, audible or visible. I think there is a problem with that control but I'm waiting to hear back from him.

In the meantime I patched a bit of lag/slew between the control signal and the (insert any receiver here), and the problem instantly disappeared - so this will be my workaround/tactic for now - albeit an expensive one; every (continuous) signal will need some glide control.

But damn - it's really worth it - I'm in modular/Soundplane heaven right now. Thanks.

Is anyone else out there doing this (Soundplane -> ExSleepers -> hardware)? Are you getting this same zippering effect?

Update 2: He fixed it! That's what it was: the "smooth" control in the Soundplane plugin code needed a T crossed or something.

Anyone on the fence about Expert Sleepers stuff: I can't recommend it highly enough!


That’s great news! Thanks for sharing. And thanks for being a model citizen by editing the topic "FIXED." :-)