Sub question
 

So recently I upgraded my headunit and now im looking to add a bit of bass. A buddy of mine has 2 JL 10w3d4 that he is willing to give me with a Phoenix Gold Tantrum 500.2. My question is will this setup work well together, and would these subs fit in an under the back seat enclosure without modifying the box?

This setup will work. Bridged at 4 ohms that amp puts out 500 watts RMS. Those subs handle 250 each. As far as the enclosure you would have to build one or pick one up from Fox Acoustics due to the 5.8 mounting depth of those subs. Sounds like a nice guy to just give you 2 subs and an amp :)

Lol yea he was a nice guy. I figured if i ran the subs parallel down to 2 ohms I could run them off of each channel @ 250watts. Didn't think about bridging the channels how would you wire this up?

Your right you could just run them parallel.

Wire the subs in series separately, then parallel them together. That'll get you a final load of 4 ohms.

http://www.rockfordfosgate.com/rftec...hmDVC_4ohm.gif

Or you can run them off each channel w/o bridging the amp.

Ive never bridged an amp before Ive heard it could shorten its life. Do any of you guys know a box that will fit these under my rear seat? something not crazy expensive, or have dimensions so I could build my own :]

Check out my first response.

do you think they would mount in this box or no?
http://cgi.ebay.com/2004-08-FORD-F15...item564326e249

They will not fit. That box has a speaker depth of 5.75 and the mounting depth of the JL subs are 5.8

on the JL literature it says 5.75

http://mobile.jlaudio.com/pdfs/10W3v2_MAN.pdf

Strange I looked at the manual too. Maybe I accidentally opened the manual for the wrong subwoofer on the JL website. Yes then it should work. I would be cautious though about buying a box that cheap. Try and do a little research on the company to see what others have said about them.

yea they want 50 dollars shipping, a guy on the web i found said he could make one for 138 + shipping but it would require a seat lift. That doesn't seem like a bad price. But even for 100 i guess the mounting depth of the other box depends on the size of the magnet seeing as its on an angle. I could just buy the ebay box and if it doesn't work use it as a template to make a larger one. :]

Go with a supercrewsounds box. Good build quality I used to have one for a single 10

You could go with this box and add the optional extended depth to fit your subs.

http://www.supercrewsound.com/04F150ECUTSdual.html

I got a question for you guys. I got all my wires run and subs plugged in, if I leave it on low they will work just fine but as soon as i add volume the subs will push once and then just pulse every 4-5 seconds. The power light to the amp flickers every time this happens. Any ideas? I ran them series and bridged the amp. so they should be running at 4 ohms.