I have made boxes before, but only had one sub per enclosed area. I just sold my Integra, so redesigning the sub box setup to fit in my Cherokee. I thought I had all the measurements down and ready to start cutting until someone addressed the issue of 2 subs per chamber. The image below is a sideview of a my enclosure (it is necessary for the subs to be facing this direction, as there are 4 subs total (2 boxes, 2 subs per box) with 3 amps and a capacitor between the two boxes, so space is tight. Anyway. I was told the pic on the top will not work, and the subs should be enclosed seperately. Ideally the pic on the bottom left would be good because it would cut the space in half, but I don't have access to anything or anyone to cut angles on the long edge of the MDF, so I think I will have to go with something like shown on the bottom right. Will this work? Are there any disadvantages to this kind of setup?

 

A mono box. Yes it will work but most of the time the subs should be facing the same way. To avoid any canelation. The only downsides it that if one woofer goes out its hard to tell. Also its only good on a single amp set up. Running two amps would require great detail on tuneing. Because each speaker would have to be receive the same power and freq. Alot of companies out make enclosures like this,-Mtx, audionbahan,kicker and such. Plus the are easy to build.

 

it is a single amp running to each box. here's a BS paint drawing of what it will be like

 

you should be fine

 

I don't think I would mount the amp to the sub box.

 

why would it matter. I have seen many instances with amps mounted to boxes?

 

vibration sometimes causes amps to go out quickly. It breaks the solder on the circuit boards sometimes. Not all, but sometimes.

 

amps are no longer under warranty either. they are the previous generation kenwood excelon amps and subs which look better than the new stuff and very reliable amps, and I LOVE kenwoods customer service. I guess I'll have too see what happens.

 

You should not have to many problems. Just slap a peice of dynamatt on the back and mount it tight. But not to tight to crack the board. Its been done for years. Just not really my cup of tea. But I do mount amps on boxes for customers that have no other choice or thats were they really want them.

 

you should be fine. a divider is prefered for numerous reasons, but it is not mandatory.we build boxes at work all the time with, and without dividers. never had any problems. i know a guy, used to have a design just like that in his grand cherokee w/ 4-12's. hit like a ****. good luck, and make sure all those woofers are wired in phase

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CrazyModGSR &raquo;</TD></TR><TR><TD CLASS="quote">Ideally the pic on the bottom left would be good because it would cut the space in half, but I don't have access to anything or anyone to cut angles on the long edge of the MDF</TD></TR></TABLE>

Why not use fiberglass on the edges? You won't need any angles that way, and it will be easier to construct too.

 

Same chamber should not be a problem at all, in fact, IMO it helps "couple" the subs together, [a good thing, if your running a mixed-mono signal to more then one speaker that you want to do the same thing at the same time.] however I do have a problem with the subs not being on the same surface, and because they are only 90 degrees , not 180 degrees out of phase with each other, polarity reversing one of the subs will not put them back in phase, placing a divider into the box will not correct the phase problem, but probably does, [or I should say would] effect standing waves inside of the box.

IMO the 3dB loss you would suffer using "isobaric" sub cabinets would be less then the cancellation you would have with subs that are out of phase, [even if it's only 80 degrees] and if properly done, would sound a hell of a lot better, with the added advantage of using up a lot less room, [ about 60%]. 94

 

well, I went to a local reputable shop today and was told my best bet for the confined space that I have is the seperate the subs into two separate chambers as shown in the pic on the bottom left and showed me a good way of calculating the angle to cut the edge of the MDF. not sure how this is bad for them to be 90 degrees from each other if they are essentially in their own enclosures then?

 

Phasing is very important for SPL and SQ, ask them which will sound better an isobaric setup or 2 subs on different surfaces, [subs in there own chamber] setup. 94

 

i may have a new design which would be easier to construct rather than trying to cut a piece of MDF along the edge at an an angle and would probably look better. evidently I would have just enough room to put 2 subs on the same plane, and be able to have them chambered seperately. any take a look at the new design (I want to go to bed, so threw this together real quick, not to scale). would there be an issue with the subs facing into each other (they would be facing about 12-15" apart). also,would the boxes need to be divided in a setup like this?

 

Yes, again cancellation would be a problem.

 

damn, wtf there's no winning

 

Isobaric 94