Isobaric 12v portable speaker

Edd Jordan wrote: Had it running again last night the bass out of the thing is mental for such a small box rear chamber for the iso barric speaker is only 9lts but it shames my 2 x 8" bin on the low notes and thats a hell of alot bigger box. i feel a dual 4" isobarric portable system in the pipeline.

The typical reason many people like isobaric subs is their ability to sound like they go lower than they actually do. Possibly caused by a much lower distortion at harmonic frequencies due to the inherent cancellation of having a forwards and a backwards facing speaker which cancels eachothers mechanical distortion. The same effect can be observed in bipolar mounted speakers were the speakers are mounted directly opposite eachother but with both speakers facing the same way relative to the box, ie. mounted normally.

Edd Jordan wrote: I know what you mean its an odd bass response realy seems to fill the room but unlike reflex you cant feel that much going on right in front of the speaker same out side it seems to have a zone of bass you can listen like being in a ball filled with bass. hard to explain but hey dose the job. iv only built about 10 isos before this one with mixed results but this one seems to tick all the boxes. hope my home hifi sub works out the same way but that will be with a 2 larger 6.5" driver.

The Boominator is the same in that respect, just outdoors, and the area is quite large. Try checking this video out that Anders202 made. You can clearly hear when you enter the "magic bubble" of sound even on an iphone mic.

http://www.youtube.com/watch?v=RWjBS5hT3ZU

(Note: the iphone mic is not accurate above 102dB. The average output should read 104dB and peaks at 115dB with the used 12V amp at that distance and with that song.)