I view speakers and power amps as a single unit. The amp drives the speakers - so most certainly the issue could be with the amp. It is possible but less likely to be earlier in the chain. Your mission, should you choose to accept it, it to identify the problem (or problems). Much like cars or health, once you have identified the problem it is then possible to take the appropriate steps.
Best amp for natural timbre of unamplified acoustic instruments & vocals w/ Revel F32?
Because these are ceramic and titanium they can sound hard, thin and sterile. But they need solid state probably because they are inefficient and for bass control. I like tubes but what are your experiences?