I just encountered something in regards to the 705P. This has happened a couple of times in the time I've had them.
I turned on both speakers, waited until they both showed a green light, and then started to play some music. But there was only sound from one of them. Turning a speaker off, then on again always fixes this. But before I did it this time, I listened to the speaker that gave no sound, and noticed that the low buzz was actually there, but there was no high pitched noise. When I "restarted" it, the whine (and music) came back.
I don't know if this sheds any light on anything at all, but I thought I'd mentioned it.
Audio Gear: Sennheiser HD 800 & HD 650, SPL Phonitor, Abrahamsen V6.0 DAC, JBL 705Ps, Dual VNF Arendal 1723 Subwoofer 1.