MX-3.com

Hi guys,

I'm planning on installing a sub and amp in my MX-3. I already know which sub it's gonna be;

Sony XS-LD125P5. It's a 12" 1400W max and 400W nominal sub.

My only question is; what kind of amp do i need to power a sub like this? I'm not planning on connecting my 4 interior speakers onto the amp (unless you guys convince me otherwise). My budget for the amp is no more than $250.

Help me out here guys, i'm gonna buy the stuff next weekend..




The Dark Prince

I like matching my subs and my amp just b/c they were designed ot work together. For 250 you won't get a grade A amp anyway so Sony will work just fine.

PS, do not hook the stock speakers into a amp. It will most likely have more power then they can handle and all you'll do is blow them up.

That's exactly why i don't want to hook up my speakers to the amp, just the sub. I replaced the rear speakers by 2 MTX 6.5" speakers and they produce enough sound for me. I just need to replace the front ones aswell.

I've looked around on the internet and i think i'm gonna get the Sony XM-SD61X (300W continuous and 800W peak power). It looks sweet and i think it will work fine with the sub i'm planning on installing.

Also, if i hook up this Sony amp to my MP3-player, powered directly by the battery, will it drain my speakers or anything?





The Dark Prince

sub wants 400 watts nominal or rms power

car puts out 14.4volts when engine is running and alternator is going

Current (amps) = Power (watts) / voltage (volts)
= 400 / 14.4
= 27.777 amps

will need a power and ground wire to the power source of 7gauge or larger. 7gauge can hold up to about 30amps. But u will probably go with 4gauge which can hole 60amps.
This would be the wire size to the power supply - which would be the alternator. So upgrading (and fusing) the power wire to the alternator and ground from the engine to the chassis would be a must.

Since the sub is 400watts rms or nominal then max should be double that or 800watts. So lets see how much current the amp should handle.

Current (amps) = Power (watts) / voltage (volts)
= 800 / 14.4
= 55.555 amps

So u should look for an amp that has a max power of around 800 watts and is fused to handle 60 amps (so an amp with a 60amp fuse).
So max amps is 55.555amps - so now u see why 4gauge wire is good. So when the amp needs max power for some big bass, it can have it from the power source.

word. and never turn it down.

It'd probably be a good idea to put your new 6.5 speakers in the front, one you've got the sub cranking you won't hear the rears anyways!