Amp help

[dirtboi22]

I have a Hifonics vii zues (class AB) 900 watts rms @ 4ohm which doesnt have a built in crossover (run my rca's to a poweracoustic crossover then out to the amp.)it doesnt sound bad on my RE SX 15 (dual 2), but when i hook up my little rockford p5002 (Class AB) 250 watts rms @ 4ohm it sounds louder!? WHY IS THIS??

[hdorre]

The difference between the two classes is efficiency. Class ABs are generally around 50% while class Ds are around 70% at 1 ohm.

The RF may seem louder because of voltage drops. Hifonics usually lose a lot of power (18% per volt IIRC) from voltage drops. RF isn't as bad with drops and is under rated.

I don't see where the title comes into play with these amps because you said they're both AB

[dirtboi22]

yea, thats my bad i just saw where it say AB vs D.

But i have 2 batteries and i never saw below 13 volts on ethier amp...?

[dugee81]

the rockford is rated 500 @ 12.5, will probably do a tad bit more than what it is rated for. hifonics is rated 900 @ 14.4, and will lost a considerable amount of juice as the voltage is lowered in the 13's. the rockford is running around the same voltage, and is even more efficient because of it.

edit: this is just a possibility, i was just throwing it out there.