I've got a 2003 F150 extended cab and will be building a box to fit under the 20% driver's side rear seat. I've been trying to decide between a JL 8W3, JL 10W1, and ID8 V.3. After doing some ready and talking to a few people, I'm sold on ID subs. I'm getting ready to order and ID8 v.3 d2 from woofersetc. I chose the 8" due to mounting depth limitations. The box will be approximately 13.5" in length, 12" deep, and 7.75" tall, and will be a down-firing enclosure. I will use 3/4" MDF for the sides and 1/2" MDF for the top and bottom to allow for maximum mounting depth. My first question is: how much room should I leave for woofer excursion? If I hold the mounting surface of the box 1" off the floor, I will end up with 5.75" mounting depth. How much room do I need to leave for this sub to prevent it from smacking my floor? If the mounting depth of the sub is 4.75", how much free space needs to be at the base of the magnet to allow the sub to function properly?

See a few posts down for my amp idea.

 

Ive been told 3in for my idq12 which has more excursion then ur id8. 1.5-2in should be ok. The more you can give it the better.

Sub amps are about power and price. I wouldnt worry about subsonic filters. If you plan on amping door speakers and havent dont it already, id consider a 4 channel thats 4/3/2 compatible.

 

You should be able to step up to the ID10 without any problem. The dust cap is removeable and will give you an extra 1/4" clearance.

Brad

 

The guy at Image Dynamics recommended an AB amp over a class D for SQ. I've got my eyes on an MB Quart RAB 1450. MB Quart RAB-1450 (rab1450) - Monoblock Car Amplifier, Power Amp - Sonic Electronix
It looks like this one should do the trick. Anybody with experience with these amps?

 

there is a supposedly a difference in sound, but class D amps are designed for sub usage and to be small and effeciant(wow thats not spelled correct). Id go class a/b for speakers but for subs i like class d for effeciency.
Subs play such a small portion of the sound frequency 30-60-80 hz that you probably wouldnt notice a difference.

 

I realize that running a pair of 12's places a huge drain on the amp during large bass hits, but considering that this is an 8 with an amp more than large enough to power two of them, let alone one, is sacrificing efficiency for SQ appropriate, since the amp probably won't be working all that hard?

 

I just scored a deal on an amp. Boston Acoustics GT-40 for $43 shipped! I stumbled upon it and remembered the recommendations to buy a four channel and run my fronts off of two channels and run the sub off of the back two. This one is capable of 3 channel operation. 55 watts RMS at 4ohms to my Polk 6x8's and 245 watts RMS to the sub at 2ohms. That should sound nice. If it doesn't, I'm not out much for trying.

 

Should be an ok start to a beginner system.

 

That setup will give you a full sound.

You can always move up to larger driver(s), go ported or add a more powerful amp for the sub if you want more kick later...

 

I think I'll be happy. I'm not looking for anything crazy, just a nice sounding system for listening to tunes while driving.