I'm gonna be building a box for my 3 12' subs. My question is I know the airspace that each sub is supposed to have right. When building the box should I have seperate enclosures for each sub with its own airspace or all of them open and 3X the amount of airspace for just 1 sub. Also what is better for a box ported or a sealed enclosure. One more thing if I mounted the amp on the top of the box would it hurt the sound to drill small holes to run the amp/speaker wires thru. I know I have to run the speaker wires out somehow how would I do that. Make a hole and then seal it up somehow?

 

1 big box is OK.

Sealed or ported depends on what you're going for. SQ or SPL?

Ported boxes are usually used for max SPL. Plus they normally require a larger box. Something you may not want to do with three 12" subs.

If you seal the screws with silicone, it'll be fine.

If you use a flush mount wire terminal plug on the box, you can seal around it.

 

Since you're using an odd number of subs, I'm guessing that you will be running them in mono. If that's the case, 1 large chamber is best because you eliminate the possibility of having unequal chamber sizes. Just make sure you brace the box to compensate, because without the dividers the box will be much weaker.

As for sealed vs. ported, it depends on your personal tastes, as well as the specific subs you've chosen. some subs like the Rockfords, sound like *** in a sealed box. Others sound best sealed. It all depends on that particular sub. I will say that generally ported boxes need to be a lot bigger, and fitting a ported box for 3 12s into the back of an f-body is nearly impossible.

 

I've got currently 2 12' pioneers mounted to the plate over the trunk. They barely hit at all and I think its cause there not sealed. When the trunk is open they don't "hit" at all. When I shut it it hits a little but not much. How much do you think I'll gain when I put a sealed box in. Basically to run the wires all I do is use a grommet and use silicon to seal around it right? A little holes between wires won't hurt nothing I bet. I said 3 12's cause I figured if I'm gonna build it why not go for 3 instead of the 2 I can pick another one up. Do you guys have any calculation charts for measuring the airspace inside a box? I would like to build it to the exact airspace or as close as I can get to what its supposed to be. I don't know much about sq/spl but basically I want it to sound good and hit hard. Not that cheap sounding bass where all you hear is the "thump" if you know what I mean. I planned after having it built buying some gray matching carpet and carpeting it. What would you use to glue the carpeting I've heard of spray on adhesives but again don't know much about this.

 

Those same two subs in a real box will be a night and day difference.

For a long time I had a pair of JBL 12" subs on a plate, being driven by a junk jensen amp. It sounded terrible and didn't get loud worth a damn. I just figured it was due to the Jensen amp. Then I built a box and was absolutely AMAZED at the difference. Same subs, same amp, 10000% different sound. It was cleaner, smoother, tighter and hit way, way, way harder.

Anybody that thinks their plate sounds good wouldn't after they heard the same stuff in a box.

BTW, "little holes" make a big difference. If you run wires through the box, silicone them well on the inside and outside to make it air tight. A hole as small as 1/8" can have an effect on sound quality.

As for carpeting, don't waste your time with that cheap automotive crap that comes on a roll at Pep Boys. Buy subwoofer box carpet from a local audio shop or from Parts Express, Sound Domain, or a similar online site. That stuff is easy to work with and is dirt cheap.

For adhesive, I like Castle Big Stick. It's hard to find though, so most of the time I use the 3M junk that Wal Mart sells. it's got a picture of a hippie laying down **** carpet in his Kidnapper van on the can.

 

I got 2 subs in a sealed box and man they are hard hitters, shakes my headlights . Check my sig for a link and see the sub set up on page 4.