That the problem is intermittent can't help identify it. After the 'SE' upgrade was done the speakers worked flawlessly for days before the symptoms started showing up again.

If you look at the thread (my DSP8000's) I believe any of us diagnosing the speakers believed the upgrade would take care of the problem. I would guess a power supply since they seem to behave themselves once fully warmed up, or 1/2 hour. Also the slave or right speaker no longer shows symptoms it used to.

I'm hijacking this gentleman's thread and will stop here.

DSP8000SEUP, 218, KEF Blade, Mcintosh Mc611x2, C49, Roon Nucleus. 'lovin the dream.