Hi Wywhcan, I better come clean right from the get-go: I hardly ever use feedback. The only power amps that I designed that use much feedback were the "Solid" amps(Solid-1, Solid-2, etc.) designed for home theater and for those dealers that insisted that Counterpoint have transistor amps. They used clever circuitry, but suffered from the same limitations of transistor amps, namely quite a lot of distortion, so feedback was used to linearize them, and to get those low-low damping factors so favored by folks that think you can predict the quality of bass by looking at a specification.
So I'm not an expert on high-feedback amps. There is, however, no reason to expect that a power amp is gonna need a big change to its feedback compensation when it is driving a speaker that has a second amplifier on its other side, running out of phase, instead of a ground. Expect maybe at very high frequencies, where the counter-driven amplifier might not sink current as well, but I can't image how that could be any problem.
That said, guys who design high-feedback amps are welcome to chime in here to help me before I sink under the weight of my ignorance.
