dual sr124dvc sealed box help

christhomaswins

hey guys long time lurker first time poster here, had a polk sr124 for a few months in a sealed box (dvc, running at 2ohms)

anyway ive been upgrading and finally managed to get my hands on another one (getting hard to find now) and want to build a dual box (or 2 single boxes?) myself.

Now from reading here i would like to build something similar to polk's recommended 1.34 cf enclosure, but two of them, i would prefer to build a single enclosure to hold both subs.

i will be wiring these (both dual 4ohm) to 8ohm, then series back to 4ohm and powering with an alpine pdx m12.

now i am fine with carpentry and woodworking etc, want to build with 3/4" mdf and just build the standard rectangular box, few questions

1. if building a dual box, should there be a divider or some form of bracing through the middle? Would i be better off building 2 single box's then simply joining them together?

2. would someone more knowledgeable be able to help me out with a bit of a plan for these, i can follow instructions fine, but the design is where im not so good.

thanks in advance, looking forward to giving my SR a companion + the box it deserves.

809peter

Here's my thought about it.

Talking from my gut feeling (mechanicly thinking) I would make one box, with a separator between the two chambers.
But talking from my experience, putting 2 subs in one space gives a tighter (much better) result.

It is hard to make a good choice between the designs.
But here's what I did once:
I made a design so I didn't have to choose. It was a box that could be modified from a 2 chamber to one chamber enclosure.

I made a separator (3/4" mdf; simmalar sized as the side panels), with a square openening in it. Then I made a cover/lid that is about 1 inch larger on all sides then the openning in the separator. But I also made it that small, so it would fit through the sub cut-out.
I drilled some holes through the separator and cover so I could make a thight seal with nuts and bolts. Ofcourse with a sort of non sticky sealant between them.

This simple trick gives you the opportunity to find out which design gives you a better result.

If you end up using the 'one big chamber' setup, there is always a good brace in your box, which makes the enclosure a bit more sturdy. So that covers also a part of your question.

I think a made, and designed, about 30 enclosures through the years.
So maybe I can give you a tip or two, if you encounter difficulties.

Hope this helps.

christhomaswins

yes this does help, leaving airspace between the two subs is definitely something to think about

MacLeod

You dont need anything separating the two subs so long as youve got enough airspace inside.

This is a great website for designing your box. About halfway down you can put in all your dimensions and the shape youre wanting and itll even tell you the size of the pieces you need to cut out. Ive used it a ton.

christhomaswins

i found a calculator on klaus audio website, seems to have helped, their design does recommend a divider down the middle which i guess will greatly help with structural integrity. I will be buying materials this week and making a start on it, will let you know how i go