Hey Guys,

I just built my subwoofer box and installed it today. I haven't installed the amp yet (that's getting done tomorrow at 4:00) but placed it where I wanted it mounted. The subs are Rockford Fosgates and the amp is also a Fosgate 3002.

I'll try to post some images, first time doing this. *crosses fingers*



And...



When the hatchback is closed, the box top seals up the rear area. I used my cargo cover and traced it on the 3/4" MDF. I'll post box dimensions later if anyone is interested. I'll get some more pictures too - it's dark now and I'm beat.

I do have a questions for you bass gurus - the salesman suggested I go with the 8 ohm speakers. I'm not really sure why? Wouldn't it make more sense to run the 4 ohm woofers and run it as a 2 ohm load? This would double the 75 watts per channel to 150 watts per channel. The Rockford Fosgate 3002 model amp is 2 ohm stable. Am I missing something here? They had plenty of speakers in stock, and they're the same price. *scratches head*

Thanks,
Steve

 

Bah - forgot to mention they are 12" Punch woofers. Hopefully it will give the little xA bass a kick in the pants.

Steve

 

The lower the ohm load on a sub the better. You will get more power and with bass the distortion you may pick up is not noticable. Stick with a good 8 ohm on your mids to highs though...

 

That's a pretty nice setup. I want thump, but I really don't want to relinquish any cargo space...or my spare tire...

 

yeah,nice hook up, im with miko with wanting to keep cargo room, theres not enugh as there is...im throwing to 10's under the seats though....not sure where to munt the amps though....
nice box again...keep it thumpin!

 

erikcooper - Yup, ok. So I'm not crazy. I'll see what the 8 ohm sound like, and decide if I wanna run a 2 ohm load on some 4 ohm speakers. I imagine the 4 ohm amp load will be enough for my taste though.

mikochu - cargo space wasn't a concern as I'm really the only thing that gets moved. I can also steal my gf's yakima when I gotta haul gear, or just use the backseats. The spare tire is still accessible. I just fold the backseat down and slide the box forward to get to it.

Steve

 

nice setup i am gonna put some of those same subs in my XB when i get it

 

Nicely done

But the weight must be a biiiatch

 

ENGLISH MUFFIN - The added weight isn't a concern of mine. It's only 60 or 70 pounds or so for the entire setup.

Since I went with the 8ohm woofers, I'm already planning on building another setup and running 4 12" woofers.

I'm working on the box now.

Steve

 

Where you get the subs? I would test the amp at a 2 ohm load first. I'd also recommend a mono rockford amp. But That looks like the setup I had when I first started out. Of course they looked different. But anyways I havent messed with this years rockford amp models so like I said try it at 2. If it cuts out, I would goto 8. But if you are wanting to put 4 subs in. Get you a 2002 200m model. It will kick those 12 inch subs like nothin else. Plus you can get it for like $125. Hey it won my comps lol.

 

That looks sweet. . . one serious question. Does that kind of a setup create sound as good as a truly sealed enclosure. I think it looks sweet, but don't want to build it first and hear it after. I'm concerned that without enough air resistance, you won't get the needed "springiness" that a sealed, ported, or bandpass enclosure would provide. How does it sound?

 

Exactly, I think he did a GREAT job with the box, but I just can't give up that much room.

I am looking at a single 10" or 12" sub right now. Hopefully I can find a wedge type box to sit back there for now. If I choose to get a second one I will have the subs on each side of the hatch area rather than right next to each other. Seems like a better idea when trying to conserve space. Problem is where do I put the amp!!

 

Not sure what you mean. That is a sealed enclosure. The box on the bottom has been sealed and divided. The top of the box is a piece of 3/4" MDF that has been cut out as the same shape as the cargo cover. This way I can still place a small amount of gear on the sides of the speaker box, and it can't be seen. The speaker box measures 27 x 13 x 13. The top of the box is what's so big.

Steve

 

Subs were purchased from BestBuy. The amp is rated at 75 watts at 4 ohms. It's rated at 150 watts at 2 ohms. Jamming those 12's for an hour at a time doesn't even cause that amp to break a sweat. It stays really cool. The 3002 model is 2 ohm stable, it shouldn't be a problem.

I worked up the box idea last night. Box is a bit larger per sub this time, about 1.25 cubic feet per woofer. It's also shaped like an M on top to fit the 4 woofers. /\/\

Steve

 

I see what you mean steve. . . it was hard to tell from the pics! Gotcha. . . I thought you were running a free air type enclosure and hoping that the hatch lid would give enough air resistance. . . my mistake :oops:

 

I have this setup right now. . . will eventually take pics. The ebay box fits fine for a 12", and they actually use the same size box for the 10" and the 12". Just search for wedge box 12, you'll find a ton of em. Be warned thtat it's only 1 cu foot, not a lot, and it's not gonna make deep deep bass. If you have hook ups from a shop, pioneer makes a great wedge that is very long and flat, so you can put your cargo on top of the box. It's costly, but it's sounds better and is more practical. With my box, it takes up about half the cargo area, and sits about 7" high on one end and about 5" on the other, short end facing the rear. With the cargo cover retracted, I can't put that much stuff on top, but I have the box is only velcro'd in, so if I need space I can prop it up onto its side to fit more stuff. My setup is POOR MAN's bass set up, works, but you won't be able to blow your doors off.

 

Well by the looks of it your driving 2 speakers...so here is the possible set up.

You are running a 2 channel amp bridged...that give you 75 watts...then you wired up your speakers in parallel. Thus your amp is now pushing 150 watts...or better put this way...your speakers are drawing 150 watts out of your amp. But you have to remember the 150 watts is not going to each speaker...the 2 speakers still have to devide the available power...so they split the 150 watts. Each speaker is then only using 75 watts each. The reason why you want to do this is so you can run 2 speakers off of 1 amp channel.

So if you have a 300 watt 4 channel amp (150 X 2)and then bridge each channel you to get 300 x 2 at 4 ohms bridged. Then run 2 speakers off of each channel in parallel...now your system is putting out 600 watts at 2 ohms. So you will be running 300 watts to each speaker and running 4 subs in the back on 1 amp.

Anyway my 2 cents.

 

Steve,
He told you to get 8 ohm subs so you can wire them in parallel, giving you a 4 ohm load, and then bridge the 3002. This would maximize the power output of the amplifier. If you are installing the amp read the manual about how to brdige the amp.

mike

 

No problem, it does look like a free air setup now that I think about it. The black carpet just blends everything in, and taking the photos at night probably doesn't help much.

Steve

 

Yup, I'm trying to learn more about it as I build this system. By bridging (I'm assuming taking the + of the left and the - of the right, might have it reversed but it's just for discussion) I'm getting the 75 watts per speaker. That's a 4 ohm load with the two 8 ohm woofers. Now to get a two ohm load (I'm using the wiring wizard at the Rockford Fosgate site) I just parallel two more 8 ohm woofers to the existing two to get a 2 ohm load.

I'm sorry if I'm repeating what you said earlier, I just want to make sure this is correct before I throw the switch.

Steve