I see mark's and everyone else's point when they say you shouldn't hear the diffrences in theory.....
But this is music we are dealing with.....a subject where feeling and emotions are tied to sounds that are reproduced by speakers....
There is evidence that peoples moods and emotions change with music reproduced at a full frequency range than say a limited range. There are frequencies our brains pick up on an almost subconcious level..... Thats why so many advocates of 70's and 80's audio studio equipment pay thousands of dolars for analog equipment that was perfected to a much further extent that the new digital equipment today.
So Im sure if you had a couple of hours of listening time in the RC challenge with detailed and emotionally filled "music" (no test tone nonsense ) you would be able to recognize the difference between amps.
As for the marketing voodoo......sometimes it is and sometimes it isn't. I use the diamond D7 series and I swear by them.....The design of the symetrical channels on the boards and use of high quality audio grade components is a a real engineering feat.
And I compared these to higher level amps (ex. audison ) and still stuck with D7's the difference's aren't apparant at first, but after a few weeks of listening you hear it.
And I'm really tired of hearing all these people that haven't ever heard a "real SQ setup" and ranting how there are no differences in amps, how hu's dont make a difference and all that garbage. If you really want to believe this then do so, just don't say that all amps sound the same and then back this up by saying they do if you strip them down to a few resistors a transsistor and a two caps.........and have themn arranged the same way on a generic board just because another "respected"
member on another forums tells you to do so......
A watt of power is a watt of power, but there are many ways of processing this signal and that's why you pay the big bucks.
BTW:
A lot of the amps on the market today are built like ****. The companies use cheap parts and try to cut corners at every turn......just to save a few dolars and this kind of mentality only shows these companies they can keep doing this.