Very strange Omnisphere issue

Here’s an interesting one. I have a rack containing just an Omnisphere instance, running a multi. The plugin is set to have no state behaviour, so theoretically should not change other than via MIDI input. I’m filtering its MIDI input so it only receives note information anyway - no controllers at all. The rack has one rack state, which remains selected throughout the song - the rack has no song state behaviour set. The patch has a longish reverb tail with a chorus effect, all handled within Omnisphere.

When I change song state, if I have a sound playing from that rack, the reverb tail audio is transposed up or down by some noticeable number of notes. Digging in, I’ve found this to be happening in the “Chorus Echo” effect in one of the Omnisphere multi patches - if I disable that effect, the reverb tail is unaffected by song state changes. It’s the kind of weird audio effect you get if you tweak chorus/delay parameters while playing on some effects plugins.

But what I don’t understand is, how can this be happening on a song state change? The rack isn’t changing, the plugin’s state should not be changing, there’s no MIDI going into the plugin on song state change. There’s no change in audio routing between these song states. How does the plugin even “know” the song state has changed?


Hi Neil,

I haven’t experienced this but it sure sounds like a clash between Steam Audio and the Cantabile Audio Engine. From your description it narrows it down a lot. Are you running low resource load when it happens? Also I was wondering if it persists with longer buffer size? Very curious indeed …


Thanks Dave - my resource load is ticking along nicely around 20-25% with no spikes. I’ve played with the buffer size from 128 to 1024 and it happens for all values, just with a different pitch of deviation. I also tried with both my usual MOTU drivers and ASIO4ALL, with the effect happening on both.

Since it appears to originate in the “Chorus Echo” effect in Omnisphere (if I bypass it, the problem goes away), I think the problem is that some parameter in that effect is being modified, and changing the effect algorithm on the fly while sound is passing through its buffers. The mystery is why and how the effect is being modified. The knobs of the effect are not changing when I change song state. And the MIDI monitor is showing no MIDI events going into the plugin at all during song state change.

I don’t know if this is even possible but do your song states have different tempos?


Wow…yes, it’s possible, and yes, those song states do seem to have different tempo…for no good reason. I must have accidentally modified the tempo on one state without noticing. Omnisphere’s “Chorus Echo” effect must be tracking the prevailing tempo, and adjusting itself on the song state change.

I set the tempos the same across song states, and the problem is gone!!

Thanks @sanderxpander :smiley:



@sanderxpander Great Diagnosis !! :trophy: