In november i decided i was going to purchase a new set of subs and decided to go with P2 Fosgate 12's, they sound like crap. im thinking its my amp seeing as its a Piece of crap. my question is what amp would best suit these subs and make them sound like they should?

 

What is the brand and model number of the amp and what kind of box are they in. Normally something sounding like crap has more to do with adjustments or install than equipment.

 

its a POS quantum 2500 class D amp.(lucky if im putting out 500)
its in a prefabbed ported box.

 

if i were you, i would look into a better amp like the rockford 1000.1 and if that still doesnt sound good enough go for a custom made box that is truly ported instead of these crap ones like at best buy that are just vented.

 

I would definitely change your box before your amp, do you know the volume and tuning frequency on the box? The P2s are only rated at like 250W RMS anyways. Where is your gain set on the amp?

 

soo you think the box is a bigger problem than the amp?
i dont know the specs of the box or what its tuned to, i figured the crappy amp was a major part, i was thinking maybe a kicker 1000.1 or fosgate 1000.1 whichever i could get a better deal on.

 

Pull out the ole measuring tape and give us some dimensions on the box.

What is your crossover and gain set at?

 

alright, my box dimensions are 36"x16"x13". my gains set at 3/4 of the way(thats about as far as i can go with out distortion.

 

If you do decide to upgrade the amp I would check out www.kcautosound.com I shopped around for about three months and Travis was the cheapest I could find. Got a hell of a deal on a RF P500DB. It is pushing my two P3 Shallow 10. My two cents... good luck.

~FB

 

Crap sound comes from signal tuning or enclosure. Check these...

Ensure your gain is set correctly. Turn your headunit to about 3/4 volume, then turn up your gain until you hear it distort, then turn it back a bit. A lot of people will say to neutralize all of your EQ settings, I say set your EQ how you want it then set your gain because if you set your EQ afterwards and it boosts your bass, then you'll end up with clipping. If you have a stock headunit, turn down the bass for the door speakers, then tune your gain. This will help clear your amplifier of higher frequencies which sound like crap coming out of subs.

Look for the filter on your amplifier and make sure it's set to LP (or low pass). This will ensure your amplifier isn't putting mids to your subs. You can set it to AP or FP (all pass or full pass) as long as your headunit has some sort of electronic filter built in.

Adjust your crossover frequency accordingly on your amplifier. Set it to 80hz, then turn it up if you need a little higher frequencies to go through.

Turn your subs away from you. Bass sounds crappy when the subs are firing at the listener because of the lack of compression for the low frequency wavelength. Without that compression distance, there is too much pressure for lower frequencies to "mature" so it sounds aweful. This is the principle that explains why bass sounds best in cars and SUVs when the enclosure is firing down or to the rear.

Make sure the enclosure is built to the specifications of the woofer, primarily the internal volume. The P2 needs 1.79cuft of internal air space for a ported box which doesn't include the space of the port. Your measured your box, I assume the external dimentions. I'll be nice and say your box is built with 3/4" MDF.
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34.5x14.5x11.5 = 5752.875 cubic inches. Divide that into 12x12x12 which equals 1728 cubic inches and you get about 3.33cubic feet for the entire enclosure, which gives 1.665cubic feet per side. Now you gotta eliminate the displacement of the port. Let's say it's 0.25cuft, now your enclosure is about 1.415cuft.
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a lot of woofers are very sensitive to the amount of air space in a ported enclosure. Small ported boxes sound like crap because of the internal compression. Great for volume, but crappy for boxes.

The only time I've ever heard a system sound crappy is never from the woofer unless the voice coil is rattling loose or something.

 

i appreciate it, gives me a little ore room to work with ill try that

 

Just out of curiosity, what are the impedance loads of your subwoofers? I think the new P2's are dual voice coil configured, but the older ones were single voice coil. Do you have the specs on that and how you have them wired? You might be reluctant enough that it's simply wiring. Other than that, I hope you resolved your issue! If everything checks okay and the sound is still crappy, expect the problem to be the amplifier. Woofers only turn electrical energy into mechanical energy. So if you have a bad electrical energy (or signal) then you'll get bad mechanical energy (or sound).