Will this work and how well?

[mdrake]

I am been doing some pretty intense research dipole and IB sub design. I have built just about every box known to man except dipole and IB over the last 20 years. I have done TL, Bandpass 4 and 6 order, bass reflex, EBS, isobaric, isobaric bandpass and many more. But I am studying dipole because of the way in which it interacts with the room ie the lack of room modes. My question is this,if ones was to take two EBS "LLT" subs and put them back to back out of phase wouldn't this create the same effect as a dipole? In other words it would not excite the room modes to the bottom top or side so the enclosure due to the null that the out of phase drivers would create; like the image below shows. This should work right and give the best of both worlds. Great transient response due to the lack of room interaction and the q and speed of a sealed box with the low-end of a bass reflex. Or I am off my rocker?

[AtleDreier]

Interesting. Would it work if I put my two sonotube LLTs right next to each other and wired one out of phase?

[crazybastard]

No. Not a true dipole sound since the drivers are still constrained by the physics of their enclosure.

[ThomasW]

My question is this,if ones was to take two EBS "LLT" subs and put them back to back ....This should work right and give the best of both worlds. Great transient response due to the lack of room interaction and the q and speed of a sealed box with the low-end of a bass reflex. Or I am off my rocker?

Room placement or some out of phase bipole configuration won't make a Helmholtz resonator sound or perform like a sealed alignment

Instead of the concept you propose, you might be better off trying some of the multi-sub placement suggestions in the Harman Whitepaper.

http://www.harman.com/wp/pdf/multsubs.pd

[Dennis H]

If your arrows represent the direction the cones move, you need to turn one of them around to make a dipole. And you wouldn't get nearly the low end of a reflex box because the low frequencies cancel in the forward direction as well as to the sides, just not as much.

http://www.linkwitzlab.com/models.htm

[Johnloudb]

I own some dipole subs (4 woofers, wired out of phase in a single enclosure). They were very tight, clean sounding - not the best drivers though. I assume you're using seperate boxes for each woofer? If not they'll attenuate with decreasing frequency - about a second order slope in the pass band. These subs I have use an active crossover/equalizer that makes the response flat.

[mdrake]

Thanks Guys

Thanks guys for humoring me and all all the links!!!! :W It looks like this is a very well studied subject. Below are the results of the Harman study. I enjoyed reading all 30 pages and will go back and study it some more, but for those that don't want to read all 30 pages the results are below. :rofl: So far from the feedback you have given me and the links provide along with my own research; I am leaning toward using two LLT's "EBS" subs front and back with two 18"s in each.

Thanks agian!!
Matt