This article is from the Car Audio FAQ, by Ian D. Bjorhovde (firstname.lastname@example.org) with numerous contributions by others.
There are several reasons: you might need those extra channels; your
amp might not be stable into the load your speakers present if the amp
is bridged; you might be a hyper-perfectionist that can't stand the
thought of an small increase in distortion; or perhaps you just don't
need more power. Car audio power is relatively cheap, and if you are
not trying to make a mega-gonzo system, you may not need to double your