You might have noticed that Bose don't advertise in HiFi mags, nor do they provide equipment for reviewing, this is because their actual specifications are pretty poor - and they would get really poor reviews. Basically Bose are a 'designer label' for the uniformed, more a fashion statement than anything else.
They get their 'big sound' by using a sub-woofer for the bass and using pretty high powers - by using high powers you can extend the bass end somewhat by providing bass boost and treble cut, essentially using much higher power for the lower frequencies (to artificially increase the bass) and lower powers elsewhere. This is why a 200W per channel Bose sounds about as loud as a 20W per channel system.