multiple sub box

[bjboertje]

When building a box for multiple subs is it neccesary to have separate chambers for each sub? if so, please explain why, thanx.

[Johannes]

If one sub cuts out, then the sub that is still working will suddenly have at least double the airspace.

More importantly, making separate chambers braces the enclosure so it is a good idea.

[bjboertje]

I m just putin 3 crappy lightnings in it and dont have enuf mdf to make separate chambers. will it work with a ported box?

[Johannes]

I think it would apply to all types of enclosures, whether sealed, ported, etc.

[bjboertje]

I mean, does having all the subs in the same airspace effect how the box should be tuned?

[Johannes]

I would think no... as long as each sub is getting the airspace it requires, it makes no difference whether or not each sub gets its own chamber.

I would definitely ask somebody else or wait for a reply though... I'm not certain.

[NAVY IC]

Originally Posted by bjboertje

I m just putin 3 crappy lightnings in it and dont have enuf mdf to make separate chambers. will it work with a ported box?

will your box be vented..??

[bjboertje]

Most likely it will be. looking for response from ng, cbfry, or paul.

[JunkTitleGolf]

I was thinking about this earlier. Right now I only have one sub but I want to make a box for 2. (My current box is a mass of mdf basically). I want to go ported and I was wondering what size of port I should use and splitting it and everything. I need to "draw" up a design on paint to show you guys and then hopefully you will tell my horrible self if I am going in the right direction and how to make the port...don't quite understand the square inches of port size yet.

[pimprolla112]

Yeah seperate chambers are a must in any case, ported sealed. If worse comes to worse make 3 seperate small boxes. Not only do you have the problem with volume as far as one sub cutting out and the other doing twice the work. You also have the problem of cancelation, and if one sub is getting different frequency ranges or more power then you have other problems. Ive done single boxes for 2 subs and it didnt sound good at all.

[balls_to_the_wall]

As long as you don't have them wired in stereo, I see no reason as to Needing seperate chambers for the subs. Although if you Do construct seperate chambers, you are free to take subs out and still be able to use the box w/ the remaining subs installed.

[NAVY IC]

I asked the question about venting because anyone who seeks help from this thread due to similar concerns is going to have to
take into account the new variable created. What I mean is that tuning will not be as straight forward as it is with one speaker per
chamber. What you'll want to consider with vented construction is, how does the tuning/venting parameters change when expanding a
box to add more subs {w/out multi chambers} vs {multi-chambered} while still wanting to roughly maintain the same tuning frequency.
You'll need to know if the subs properties concerning the enclosures dimensions would increase or decrease, if the differences are linear
or exponential and how to figure out the formulas if the new dimensions are not proportional to the number of subs added.

I know that you, (bjboertje), stated that your looking for replies from only a few people, so I'm adding my for
all of those that are browsing through the threads and using the search features to find help with similar concerns.

[bjboertje]

thank for the input, all 3 subs will be wired to a mono amp, so they will get all the same power, freq, etc. i just said i was looking for replys from those people because i know they design enclosures and they know what they are talking about, not that others don't or can't reply.

[NAVY IC]

Originally Posted by bjboertje

thank for the input, all 3 subs will be wired to a mono amp, so they will get all the same power, freq, etc. i just said i was looking for replys from those people because i know they design enclosures and they know what they are talking about, not that others don't or can't reply.

Yeah I feel you, that's why I don't reply to as many post as I used to.

[CBFryman]

3 drivers, as long as they are the same make and modle and all of the suspensions have been equally broken in, will act as 1 driver if all given the same signal and airspace.

If one driver required 1cuft, two will require a shared net space of 2 cuft. three will require 3 so on and so forth. You only blow subs when you are uneducated about your equpitment or are at least halfway trying to.