View Full Version : Sealed box questions?

01-21-2012, 11:26 PM
I've always wondered, is it bad for 2 subs to share a chamber in a sealed box? Pros cons?

01-21-2012, 11:43 PM
Well i guess if one sub was damaged it could mess up the other one.

01-21-2012, 11:47 PM
Usually I build sealed enclosures with separate chambers as it works as great bracing and if you ever have issues with one of the speakers you can still have some bass by running just one of them.

Moble Enclosurs
01-22-2012, 12:14 AM
It can actually be quite involved when dealing with multiple driver beyond a certain point in a common chamber. The response, depending on the volume, will be affected differently in each of those setups, so you would have to understand the limitations involved to have a correct answer to that because the correct answer is dependant on the application.
for instance, say you have 12 10" subs in a common chamber 18 cubic ft enclosure. You have to deal with the fact that compression factors will not be as accurate as if they were individually sealed because of the overall volume. And that volume may have a lf cutoff too low for the drivers to operate efficiently. Though it is sealed, excursion can become a dominant factor in response output, especially below cutoff.
Now, if they were in separate chambers, the cutoff would be much higher but output may be comparable to the common chamber along with excursion control being greater. So, I have to agree that having them in separate chambers will evidently, depending on the application, have more pros than cons over a common chamber.
And again, that is application dependant, but as an overall from dual sub enclosures to multiples of tens. You will have a small loss in compression from that of a common chamber unless you make the ratio for each subs volume less than recommended.

So, if you have only say 2 subs, the common chamber design will effect the output less even though a ratio is still achieve with 10 or more(example number of drivers). So for sake of simplicity, having them in separate chambers is best. But if you know what to do with a common chamber, you may reap some benefits that a multiple chamber design might not achieve, which is lower cutoff, and higher efficiency over a specific range.

I hope that makes sense a little.

01-22-2012, 12:15 AM

Moble Enclosurs
01-22-2012, 12:16 AM
I have to add, that you can also lose potential output in a common chamber if not done correctly, due to driver cone area in relation to excursion (amoung other smaller factors). Think of this......a larger enclosure(common chamber) with multiple subs, will act more and more like a larger sub with less excursion due to limitations. There is actually a lot to be said for this effect in most designs....not just sealed.