[akersten]

Sure. Replace "independently" with "dependently" in my comment. That distinction changes nothing about the novelty of such a system.

The volume knob on your stereo from 1960 controls both the left and right speaker volume, at the same time. Woah.

[yccs27]

Sorry for having "someone is slightly wrong on the internet" syndrome, of course it does not change your point about an overly broad patent.