Ok finally just got my new subs yesterday and I thought since im a car audio guy Id go ahead and share a little knowledge and maybe help answer some past a future questions about subwoofer selection for our cars.

Ok So first let me start by saying I bought my subs from a place called Gibraltar. Its basically a huge fleemarket here in michigan and if your from michigan Im sure you've heard of it. Ill get to more of that later.

Ok so basically first things first you need to choose your box and how much room you want eaten up. Ive seen a 10" box that fits where the stock subwoofer goes but cant comment on its efficiency. From there I will use the 93+ camaro as an example as that is what I have.

I have personally seen 3 boxes for 10" and 12" subwoofers. Since the boxes are the same size I choose the 12" box. Dont get me wrong Im a SQ (sound quality) guy all the way but its nice to know I got a little extra when needed (i.e. when I got some young girls in the back seat that wanna hear the boom!).

OK when choosing your box you need to keep in mind the internal volume of the box. Most camaro boxes are about 1 cubic foot.
THIS IS VERY IMPORTANT !!!!!!!!!!!

Lets just say you bought this box
http://cgi.ebay.com/CUSTOM-12-SUBWOO...QQcmdZViewItem
Thats the one I bought fyi, That box is (acording to the reported specs) about 1 cubic foot.

Now when I went to buy my subs my guy gave me a choice between about 6 subs and I want to let you know how I knew which subs to pick when givin a decision like that.

First I deciced to stick as close the high end of my price range as possible. This was $150. That alone narrowed me down to 3 sub woofers.

Here was the lineup

POWER ACOUSTIK FUBR-12
http://cgi.ebay.com/2-POWER-ACOUSTIK...QQcmdZViewItem

My Offered Price $135 out the door

HIFONICS Brutus BX12 D4
http://cgi.ebay.com/2-HIFONICS-BX12D...QQcmdZViewItem

My Offered Price $160 out the door

SPL-S3-12H
http://cgi.ebay.com/SPL-12-PAIR-2000...QQcmdZViewItem

My Offered Price $160 out the door

So I went ahead and bumped the Power Acoustics off the list and decided to stick with the 2 sub woofers for $160 because if I went on price alone I could just choose them, but for specs I bumped them off for a few reasons.
At first glance the PA's (power acoustic) look pretty beefy with their massive 200oz magnets and all. Of course this is nuthing more then clever marketing because they know the general public looks for a larger magnet, but why?

Magnet size is associated with a bigger boom (and it should be to a degree) because the bigger the magnet the stronger the magnetic pull (in theory) which when voltage is applied the voice coil of the speaker this allows more cone excursion (the maximum amount the cone moves in and out) which in turn displaces more air and thats where you get your boom.

BUT take a closer look and you will see it has a puny 2" voice coil. Smaller voice coils suck for many reasons but one the biggest is the fact they cant stay as cool as a larger voice coil, A hot voice coil is a blown voice coil. A voice coil FYI is nuthing more then a cylindar with wire wrapped aroung it, this is where your speaker wires connect.

Lets go ahead and bring up a speaker diagram at this point so you will know what the different parts of the speaker are called so you go to purchase them you will seem a lil smarter and less likely to be taken advantage of.

http://www.mtx.com/caraudio/education/speakers.cfm

Ok now back to the speaks.
One thing that concerned me about the Hifonics was that the voice coil was completely visable. This was a good thing for cooling but any contamenents in your box and poof there goes that. The vented coil is good for cooling and when I say vented I dont mean it has a vented pole piece, Which is does as do almost all subs. No what i mean is right below the spider in the basket there are cutouts and you can look right in a see the voice coil.

Now upon closer inspection I seen that both subs are dual voice coil but 1 set you can get in dual 2 ohm which I prefer with 1 amp. If I had two amps or a 1ohm stable amp then they dual 4 ohm would be nice.
Unfortunaly when wiring 2 dual 4 ohm subs in paralell you cant bridge the amp because your load would be 1 ohm, this will kill most amps.
If your clueless at this point just look up ohms on google for subwoofers, its simple math.

Ok all that aside what really counts is the box the subs are designed for.

First you need to know your box volume, Mine is aprox 1 cubic foot per sub.
Now we need to know the volume required by each sub.
You required sealed volume will be less then your required ported volume.
If you dont know the difference between sealed vs. ported it basically goes like this.
A sealed box generally sounds better as far as sound quality and acurracy goes. Your subwoofer will handle more watts but will also take more watts to get the same amount of boom as a ported enclosure.

A ported encloser can sound real nice when the specs are dead on (ported boxes are much LESS forgiving when the size is incorrect for the subwoofer). You will also need the correct port size and placement for the ported encloser to work. You can generally increase the ported box size to increase the boom but you decrease effeciancy and accuracy.

The camaro boxes are sealed because there just simply isnt enough volume to make them ported for 12" subwoofers.

OK now heres them specs\

Hifonics
Sealed Enclosure Size 2 Cu Ft per sub

SPL
Sealed Enclosure Size .95 Cu Ft per sub

We also need to know speaker displacement, this is the amount the speaker takes up in the box.

Each one of these subwoofers displaces aproximatly .1 cubic foot of air.

This means if my camaro box is 1 cubic foot and my SPL subwoofers displace about .1 cubic foot then my enclosure is now .90 cubic foot.\

Almost dead on for the required size, hmmm kinda obvious which ones to choose at this point. Further more then SPL's have 145oz magnets compaired to 100oz on the hifonics and the subs just look better. Oh did I mention my amp is SPL as well?

Now if you dont know the listed recomended enclosure size for your subs or their just not listed dont worry you can calculate the enclosure size with a few variables.

http://www.carstereo.com/help/Articles.cfm?id=30

Before I go on I will tell you that the SPL's are one tight squeeze in the camaro box and you need to keep this in mind for any sub purchase. The box I bought is shaped in a way that the box itself actually limits the possible magnet size of the subwoofer because it cuts right into the subwoofers path.

I actually had the turn the subs on an angle because the magnets are grooved and thank god they were because if they didnt have those grooves (yes that 3mm difference) the subs would not have fit.

Also dont worry if you subs are close but dont fit most speakers shops sell carpeted rings that will raise your subwoofers anywhere from 1/2" to 1".

Now dont worry if your box is a little too small for your subs. Thats where poly fill comes in.
Whats poly fill? Well its basically the stuff you can buy at any fabric shot and is used for things like stuffing pillows.

More on poly fill here
http://www.klausaudio.com/articles/c...woofer-box.cfm
You can buy at your local fabric shot or here
http://www.crutchfield.com/S-pn8EdjO...g=741&I=027808

In the case of the SPL's the speakers actually recommend you using poly-fill in a 1 cubic foot encloser, they recommened 20-50% loose stuffed
I use about a 55% fill.

So hows it sound? Well I think it sounds great. Nice tight bass with plenty of boom to spare. I only turn the sub out level on head unit up about 40% because its way more then needed but its also nice to know its there when I upgrade my highs again.

I would definetly recommend the spls when using this small camaro enclosure. Heres so pics of my setup.

Again I had to turn the subs on angles because of the magnets hitting the box.

 

How does the construction of that box look? Do they use 3/4" MDF?

 

Yeah I think it is 3/4". The box feels and looks good. I dont think you could put powerfull enough speakers in the box to blow it part, what I mean is speakers that would blow the box apart would require alot larger box. Anything that wants 1 cubic foot or less probably wouldnt be able to split the box at any seems.

Im happy with it for the money paid.

 

well....i'm a kicker and rockford fosgate guy so we will have some differences but overall, the post is a useful tool for the beginners. i have had 3 sets of subs go through my camaro. i have had a single 10" alpine type e (first sub and POS), a single 10" kicker comp vr (older version but hit twice as hard as alpine for same price), two 10" kicker comp vr (newer 06 model and they hit very accurate but not quite as loud), and i now have two 12" kicker L5 (pretty accurate but loud as hell!). all have rubber around the cone cause they put better quality into there subs. i customly built every box for all these subs and none of them have broke/leaked any air. i made it fit perfectly above the well so it wouldnt slide around when i felt the need to punch it around a turn and i have two amps, one for all four of my speakers and the other for my subs underneath w/ no real free moving air. NEITHER amp has over heated!!!!!! rockford, IMO, makes the sickest amps ever. wired everything myself too. this system rocks. stick to rockford or kicker is my recommendation. and use poly in your boxes cause it helps alot since we cant have HUGE and HEAVY boxes in our cars. if you want accuracy, go with 10s but like he said if u want loud, go with 12s. and those PW's you were gonna buy are very loud. my friend had them in his sentra and i thought i was gonna go deaf.

 

hell ya Gibraltor trade center all the way i live like 20 min from there i get all my subwoofer stuff there. you can talk them down to anyprice just about! very cool place but shady if you dont ask the right questions!