rockford sub and amp question
 

Looking at getting a sub for the 370, was wondering if the rockford fosgate R500×1D amp would efficiently push one 12" p3d2 sub. Just want to make sure if would power the sub enough before I purchase. Any input is appreciated, thanks!

Impedance of the amp and sub match (2 Ohm) and power ratings (500W amp, 600W sub) are close enough. 500W should be plenty in such a small listening environment. How do you plan on wiring the dual coils of the sub to the mono amp?

Would the p3d2 10" (1000watt) peak, or p2d2 12" (800) peak pair best with this amp?

That shows the coils in series - 4 ohm impedance. I didn't look real close at the specs so you may want to check and see what the amp output is at 4 ohms.

The main parameter is impedance. The impedance of the speaker should match the impedance of the amp. Speaker impedance can be higher, but you lose some volume. If speaker impedance is too low, you run the risk of damaging the amp. In this case, since the amp will handle loads down to 2 ohm, you will be OK.

As long as the speaker is rated for the same or more power as the amp, you are OK. Unless you plan on using a bigger amp later on, no need to buy a speaker with "excess" power handling capabilities. But it doesn't hurt anything either - assuming the speakers have the same efficiency (being from the same line from the same manufacturer, they should be close), they will all put out the same volume per watt.

The amp is 250 watt (rms) @ 4ohm. Do you think that will be okay?

Depends on how much bass you want. My rule of thumb is to get more amp than you think you will need. You can adjust to desired output level.

Okay, thanks for all your replies southark. I really appreciate it. I will look for a more powerful amp then

You're welcome. Keep in mind that it takes 10x the power to double the volume. Eg, if you start with a 100 W amp and want twice the sound, you need to step up to a 1000 W amp. I'm not sure how much bass you want, but 500 W ought to do it in a small car. You'll probably seldom want to use that much on average but it provides some headroom for the "thumps." Of course, if you like it really loud, the sky's the limit.

Ok so it will be safe for the sub to be underpowered a bit?

Underpowering can lead to clipping which is not good for the Amp or the Sub in the long run. That amp is a good selection due to it being Class D and will run cooler and more efficiently than your standard Class A/B amp. Considering the amp is 500w RMS @ 2ohms, you want to provide it with a 2ohm load to take full advantage of it's power output. I would use a 4ohm DVC sub(P3D4-12) and wire it for 2 ohms(unless you have purchased the sub already). Another way to maximize bass output is "corning loading". Placing the sub as far back in the Hatch area and in the corner will provide more output at a given frequency depending on the resonant freq of the sub/enclosure and vehicle acoustics. All in all, 500w RMS is plenty in a 370z.

http://img.techpowerup.org/140910/Capture084.jpg

^Roadster, I talked to JL audio AND RF about clipping because I bought the amp the OP is talking about to drive the shallow mount JL 13" and BOTH JL and RF said clipping is BS, it doesn't hurt the amp or sub, and both said peak output is complete BS too.

The one I got came with a paper saying that it was actually rated at 598Watts and peaked at... 2400 watts or something

Not exactly true, but in a roundabout way........ Underpowering will never harm your speaker. The harm comes when people increase the amplifier gains to get louder, and put the amp into clipping. When gains are set properly, clipping is not an issue, and any amplifier will suffice.

^This. I forgot what exactly they both said, and they said this exactly.

And most people set the gain way too high because it sounds louder.


RF sets the gain where it should be.

And that, My friend is complete snake oil. A clipping amp will most definitely cause mechanical failure of your subwoofer, just at an undetermined pace. They simply gave you a sales pitch.