amp quality

[h2opolo]

Does anyone know anything about Pioneer's GM series amps? They seem to have good reviews online but in audio forums they don't have a good reputation. They are CEA compliant though. I want to use it to power some speakers at 2 ohms. The speakers I have are 100 watts rms and the amp gives me 112.5 watts rms at 2 ohms per speaker.

I have also considered the JL jx series which will give me 90 watts rms at 2 ohms per speaker. I know jl makes quality amps but this is underpowering the speakers.

How would the two compare given JL has a good reputation but the pioneer is rated for more power? The amp ratings are both measured at 14.4v.

[Chexi]

If those amps ratings are at 14.4v, I would say they both would be underpowering your speakers.

[h2opolo]

Alot of the amps I see are rated that way, even some of the high end jl amps.. I think thats normal; correct me if I'm wrong. Do you know the difference in quality and accuracy of rating between the two?

[MLA]

"the amp gives me 112.5 watts rms at 2 ohms per speaker"

If thats the 2 ohm output of the chnl, then with a pair of 4 ohm speakers wired in parallel to = 2 ohm they will divide that 112, netting 56W rms p/speaker. Or, is the amp 225W rms x 4 @ 2 ohm? If so, thats a substantial difference.

[h2opolo]

4 ohms: 150w x2
2 ohms: 225w x2
4 ohm speakers, 2 in parallel per channel, so 2 ohm resistiance within each channel, so 112.5w per speaker. Do I have that correct?

[MLA]

If those specs are correct, then yes, you are correct on your net wattage to each of the 4 speakers.

But, that amp doesnt look to do hi-pass, just low-pass and full-range. I would pass on it.

[nyryan2001]

H20- if I were spec'ing a system... And everything being perfect.... I'd go full regulated amps so you get precisely the same power delivery at 12.4v as you do at 14.4v when the engine is running. Arc and JL are a few with the fully regulated amps on their high end lines.

non regulated amps, I am shooting for a true RMS power delivery 10-20% above the speaker's rated RMS rating... That way when at rest, 12.4 - 12.6v, you are at only 10-15% below the max RMS rating... Pretty much split the difference on that swing of RMS power between 12 and 14v.

^^^ and I say 12.4v, because unless you have about 6+ batteries, no one maintains 12.6 with the engine off and even medium volume. I have 5 SRM29s, and my 12.6 immediately drops to 12.4v when I hit 30-40% volume.

but yes, I am with you, I like to give max power to speakers. There are a lot of Class D's that will do 200w x4 at 2 ohms. Going with pioneer, are you price sensitive?

[h2opolo]

Yes I am price sensitive. At the same time I am aware that you get what you pay for. Pioneer amps seem to have a fair amount of power for the price but I am hesitant because I am unaware of the quality. I may just go with some Polk audio amps to match the Polk speakers. I haven't heard anything bad about them.

[MLA]

H2O,

Quality aside, that Pioneer amp will not run in hi-pass. I would highly suggest finding an amp that will.

[h2opolo]

Thanks MLA, that makes sense. Ill pass on the pioneer.