Do the surrounds really need much power

See my post on the other thread you started Robedk for my experience.

It should be true ,but with the power craziest I see ,I doubt it now....more power more power.....

Yes, the Dolby Digital, DTS etc. will have the surround channels as separate discrete channels where they can definitely use the full bandwidth.  However, movies are not mixed this way.  You will not actually have a lot of sound output on the surround channels, even during heavy action scenes.  There might be one or two scenes here and there that may use more impact on surround, but for the most part, there is actually very little sound level coming out of side/rear surrounds.  You can definitely get away with smaller power amps.

I would say its not about bandwidth as much as dynamic range.  All the special effects are sent to surround channels and can be QUITE dynamic.  Explosions, doors thudding closed, etc.  You need significant power to support all these noises they stick in the surround channels.   

 

Brad