Well here are my 2 cents...
When you spend your money on your system, you want to buy good sounding, long lasting, and efficient equipment. It is true that amplifiers all do the same thing, amplify. But what sets "most" amplifiers apart? Marketing. Occationally some amps come with really innovative FUNCTIONAL features that either keep them cool under hot temperatures and/or are built incredibly well, but most amps are just run-of-the-mill and boring. When it comes to an amplifier for your highs/mids, (in my opinion, the most critical of the audible bands) you want something that sounds good and wont shut off on you when you jam for a couple hours on a road trip. I have always been a fan of the Precision Power amplifiers. The ones that I like, the Art Series.2, and the early Power Class (not including the .2) are not even made anymore. You can go to eBay and find them all over the place (beware some scam artists that sell dead, abused ones though). This is because they are BUILT well out of great internal parts and they sound wonderful.
What many people tend to do is study stats all day long and make their decision that way. Thats fine for the people that think something sounds better if a spec sheet tells them it does. Thats really not for me. Car audio started when some guys wanted to put great sound in their car. As materials and methods advanced, so did the car audio product. The term "audiophile" is what the basis of what car audio used to be, but has been slowly pushed away as companies focus more on flashy lights, pointless displays, and tv monitors galore. Car audio used to be about satisfying the need for your own great sound instead of getting people to look at your flashy, epileptic seisure inducing display of lights.
Many amp companies realized that they didnt have to build amps to please the audiophile anymore. Kicker, for example, used to make incredible amps. Their ZR series amps were phenomenal. One of my good car audio friends that would compete with ZR amps and Solo Baric subs got a sponsorship from Kicker and tells me all the time that his old Kicker equipment sounds better than his brand new Kicker stuff. He did add that the new subwoofer technology does impress him and that it has developed subs to handle more power, but not necessarily "sound" better. This is just one example of how amps can change without the masses knowing about it. Amplifiers are an important part of your system, but ultimately a high quality cd player and high quality speakers will give you a better grasp on your sound with a focus on the latter. Speakers make all the difference. Amplifiers just make sure that they are taking the signal from the cd player and getting it to your speakers with power, control, and purity. If you want to spend 1000 on an amp and a set of components, spend 800 on your speakers and 200 on your amp. I guarantee it will sound better than if you bought 200 dollar speakers and an 800 dollar amp.This isnt to say that buying a quality amp will not give you benefits. It surely will. But you dont have to mortgage your house to get a good amp, save that for your speakers

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