In article .com,
wrote:
Audio Power Amplifier Bandwidth

I am building a 500 Watt power amp with a bandwidth of about 1MHz
at full power. I think that this same design can be pushed to about
10MHz max.
Question: Is there any science to prove whether this should sound
any better than a 20KHz amp?

Unless you have some CDs that contain audio frequencies up to 10MHz and a
pet bat, I don't see how it could make any difference. There would only
be the possibility that any electronic instability could produce
inaudible output components, so a problem of this kind could pass
unnoticed for a while, except for the heating effect on your loudspeaker
cables, or possibly interference to your neighbours' radio reception.

Rod.