When shopping for an amp, there are many specs that one must keep in mind. I am doing some online searching, so I have this question: In what order must you consider each of the following:

RMS watts per channel
Freq Response
THD at Rated RMS Power
Signal to Noise

For example

Lightening Audio Bolt B400.4
75 RMS X 4
N/A Freq Response
THD .08%
S to N 90 dB

R. Fosgate Power 550X
65RMS X 4
20-20K freq res
THD .05%
S to N 100dB

What makes one better than the other, which woulf you choose in this example.

I am looking to ppower infinity 62.5i and 605cs how much power do you think is sufficient, as I do not want any dormant power that isnot being used. The Clarion deck I have is not that efficent with a rating of 90 I think, does this matter when looking for an amp?

Thanks

Amer786

well.. if it doesn't say Pyramid, Legacy, Boss, Audiovox, Road Rage it should be allright..

99.9% of the population can't tell the difference between any 2 decent amps of the same power. Amps like earthquake, JBL, Blaupunkt are all good clean amps..but the crossovers built into the amp are kinda crappy..you'll be allright with pretty much anything you buy.. a low cost amp with decent crossovers are Clarion, Alpine, Lighting audio, kenwood and MTX...

Again, this is a judgment call. You need to hear the setup you have in mind to know what is better, in your own opinion. Also, different manufacturers have different rating. Whereas rockford fosgate may rate an amp at 200 watts, JL may rate an amp at 200 watts, but the JL amp puts out way more power...this may not be realistic, but this is how different companies can have different ratings. Trust your ears, they won't steer you wrong.

i have that RF 550X amp, i have no problems with the sound quality, like mohowkboom stated, more than likely people wont be able to tell the difference between two amps, like the ones you mentioned.
one thing i heard about S to N is that the higher the better, i dont know why, but its what i heard. also, check the ohm ratings on the amps, cause the 550X is 65watts x 4 @ 4 ohms, and 137.5watts x 4 @ 2 ohms ( something like that )

I have used Orion and MTX, no problems with either

What should the output on the am[p be, is there a percentage that it should be of your speakers total power? I have heard that your RMS per channal on your amp should be in the top one-third of your speakers output, so 90 WRMS speakers should be powered with at least 2/3 * 90 = 60 watts rms per channel. Any thoughts?

there is no must as far as what to look for. some people buy by numbers, for sure. i can tell you that me personally, rms wattage per channel backed up by a birthsheet or a brand name i trust is on the top of my list. i dont even think about any of the others.

what i consider when i shop for an amp is whether its class a/b or not. how steep the slope is on the adjustable crossover. whether it has a remote gain on it. if it has a bandpass crossover on it. how much it costs. thats all i can think of off the top of my head.