Its not just the breaker but the wiring as well that would have to be upgraded; doing just the breaker would result in a Fire Hazard.
FWIW, a 20 amp circuit is a lot of power for an audio system and should enough, unless you have a really really big system!
FWIW, a 20 amp circuit is a lot of power for an audio system and should enough, unless you have a really really big system!