"add complexity" ... oh yes!
Assuming R50/R52/R53 not R56.
The H/K system amp and speakers are an integrated whole. The rear speakers for example are dual voice coil, each coil two ohm impedance. So four amp channels drive the two rear speakers.
You can find ripped out H/K speakers - but I'd be much more likely to suspect that the H/K amp is going bad and making the rear speakers sound bad, rather than the speakers themselves are bad.
