Building a sub box for a friend using mdf for the bottom and the top peice out of fiberglass. Planning on running 2 Kicker L5/L7 15" depending on how much he wants to put out, running those with a Kicker 1200w amp. How does this sound, and will the current 4guage wire handle the 1200wRMS? And wiring it as so below?

 

That's how you would wire two 4 ohm DVC speakers for 1 ohm, yes. The bigger question is whether or not your amp is 1 ohm stable. If it is then great, you're set. If not then you need to rethink things.

As for the power wire, 4 gauge is cutting it for 1200 watts if the amp is capable of putting out the power (ie not sony, etc). You should be fine with 4 gauge, but you might as well upgrade it now if you’re planning on running two amps or thinking about upgrading the 1200 watt in the future.

What kind of amp is it?

 

"running those with a Kicker 1200w amp"

It's Kickers amp that runs 1200w RMS @ 1 ohm

 

that is correct with what you have listed...

 

Blind, sorry

Be happy, you will be fine

 

sweet, thanks.

 

If this is just the sub amp & there is a separate mids/highs amp, run 0 gauge to a distribution block and then off to all the amps from there. Just for reference, if this is just one dedicated line to a KX1200.1, it comes with a 150A fuse. It wouldn't be a good idea to run a "real" 1200W amp from one 4 AWG line. The resistive losses alone at those currents could present a problem. They're not huge by any means, but when you start sucking 100+ amps, small resistances get amplified quickly. Check this out. It's got a chart for supply line sizing:

http://www.bcae1.com/wire.htm

Also, if you don't already have the subs, I'd recommend something else. There are better subs for less money. I put a pair of 12" L7's in the Camaro powered by a KX1200.1. I love the amp, but the subs fall out (GREATLY) when following a bassline. Jim modeled the 12" L7's and found that you need something retarded like 12 cubic feet chambers to make them sound OK. The Kicker "recommended" sealed 0.88 cu ft sounds like hell...They'd do decent in an SUV, but not in an F-body (I don't know what your friend drives).

I ran 10 AWG from the amp to the subs, but you could get by on 12 -- MUCH easier to find in my area.

 

Interesting, we came up with a rounded total volume of 5 cu ft. in the back of his 89 bird. What else would you recommmend that would give more bass, right now he's running 3 12 JLW3, and probably 800-900w RMS. And for some reason he wants more, I don't think he cares too much about quality.

 

Here's a thread with plans for a ported well box I was working on with input from some of the guys on the board:

https://www.thirdgen.org/techbb2/sho...hreadid=327887

I concur that 5-6 cu ft can be squeezed into the well area (and out a bit more, according to the box plans). Here's a link to the latest design:

https://www.thirdgen.org/techbb2/att...postid=2602642

And here's some links to a few subwoofer sites:
http://www.reaudio.com/
http://www.adireaudio.com/
http://www.edesignaudio.com/us.php

You can go with the XXX15, Brahma 15 or a few others. Some cost more than comparably sized L7's and some less, but these ALL sound better. Some get as loud or louder. Note that when I say "costs more/less, this is based upon my paying $220/each for my S12L74's. The big problem with my current setup is the kick drum gets nice and loud, but most everything else sounds low, comparatively. Deep bass is nonexistent. This all has the effect of making the subs sound lower in volume overall and totally impossible to mix. My 10" CompVR's played much better, but not as loud. It WOULD fix matters quite a bit if you place them in a 5 cu ft box, but as so many others have said here: It's just better to start off with a better driver than to get a bad one and try to fix it after the fact.

 

hmm.. thanks for the input I read your thread you linked me to, so the subs sounded decent in a 3 cu ft sealed, but better of going with something else that doesn't need to be so tuned. Maybe we'll go back to the drawing board I wouldn't want him to spend all this money and be dissaponted.