Thread: Subwoofer Placement-magnets too close?

Originally posted by ddt
In the enclosure I'm building (I'll post pics soon) the subs will have their magnets pretty close together (back to back). When I say close I mean 1/2" from each other. This is out of necessity, due to space constraints, rather than in the design.

Will this negativley affect my subs performance? If so how much? Can I use some sort of barrier between them?

I can feel the magnets pushing away from each other it's so close.

do the speakers have a vent on the bottom of it? if not then it's ok. If it's vented, then you should have at least 2 inches between them.

Im assuming he is talking about a voice coil vent. They have a hole in the center of the magnets, so YES they are vented.

It all depends on the voice coil travel. Because they are vented on the bottom, they will be pushing air what can happen is air comming out of one woofer will force its way into the other and cause voice coil travel resistance, causing voice coil burnout. That is something YOU REALLY WANT to stay away from. Try to install them further away, or at a slanted angle. Enough so that when they push the air, the air from one speaker wont go into the other speakers vent.

What about putting them facing each other instead, in a clamshell configuration, running them out of phase so that they run push-pull?

This works - it's all a matter of whether it works with the space you have available.

You'll find some examples (and excellent advice) at the Soundstream Heavyweight Boxing site. Have a look at Section 2 in particular.

Enjoy!

C!

If you're going with weird shape multi-subs boxes or boxes with subs on different sides of boxes you'll end up with subs that deconstructively interfeir with eachother. Maybe not as much as 180 degree out of phase but a few degrees depending on what hz. To build a multisub box and get it to sound as loud as possible, you have to understand wavelength, tranfer function, Thiele-Small parameters of the subs and how to construct a box. a loud box is a simple box, sealed, subs side by side, facing up or down or back of the vehicle. If you're building a single sub box, then it'll sound good no matter what you do b/c you don't have the second sub to interfier with eachother. If you look at all the prebuilt car specific boxes from JL and MTX (they did their homework) most of them are single sub boxes. If it's a 2 subs boxes, both subs are on the same side of the box. If you look at SPL vehicles at the db drags, they have flat walls of subs or subs that have equal distance tween them and the windshield. It took Gate's bronco 64 10" subs to hit 171db with different sub to windshield distances on all the subs and JL's Metro with 4 15's with equal subs to windshield distance to hit the same SPL.