isobaric bass reflex box questions...

[impaled 10+ year member]

desperate times call for desperate measures.. in this case, a severe lack of space.

an example of this is the second pic down.

http://www.the12volt.com/caraudio/boxes4.asp

is this common at all? how would it work for two 15" l7's?

are there any other places with more information on isobaric ported boxes?

and most importiantly, how is the sound quality/output (generally speaking)?

Click to read more...

 

[impaled 10+ year member]

ttt

 

[helotaxi 5,000+ posts]

Sound quality is generally the same as a normal setup, sometimes better because having the two drivers out of phase cancels out natural nonlinearities in the individual drivers (this assumes that the drivers are consistent in their production), sometimes there are issues with mechanical noise from the suspension of the inverted driver. Efficiency is halved, meaning that it will take twice the power to get the same output because what you have effectively done with and isobaric design is doubled the moving mass to get a halving of the Vas.

 

[path2spl 10+ year member]

that must be so hard to get to work right

 

[helotaxi 5,000+ posts]

that must be so hard to get to work right

It's very simple actually. As long as you know how to wire a sub out of phase, it's no different than just wiring up two subs. The only difference is the size of the box.

The back edge of this double edged sword is that while you save some space relative to a single sub, the iso-pair still want the same tuning and port area as the larger box which will now require a much larger port displacement thus negating a lot of your space savings. Couple that with the inverted mounting of the outer driver and your setup may actually take up more space depending on the subs in question.

 

[DDeitz 10+ year member]

^^but it still has a cool effect, and thats all that matters

 

[helotaxi 5,000+ posts]

The effect isn't nearly as cool if it still doesn't fit...

 

[impaled 10+ year member]

i talked to kicker and tech support stated that the l7's were not meant to be mounted isobarically... why could this be???

 

[helotaxi 5,000+ posts]

No reason it can't be done. The Kicker "Solobaric" series of subs were originally designed to emulate an iso-pair with a single sub (high Mms, low Vas) and the first series used a realy tiny box. They've kept the name but forgotten the idea behind it. The one thing that you'll have to do is put a spacer between hte subs to provide clearance for the surrounds. That's the only thing that "wasn't designed" for an isobaric mount.