[Fjendbo]

Hi all you knowledgeable people,

I was wondering the other day, partly inspired by the Steinway Lyngdorf Model B speaker, if you can combine dipole and sealed woofer in one solution.

The Model B uses 6 12" woofers in a (what I believe to be) sealed cabinet, 3 front and 3 back, wired out of phase for dipole effect. SL Audio state they have the surface area of 6 woofers, but I don't see or understand the real benefit as only the surface of 3 woofers play forward and 3 backward. Just as if you would mount 3 woofers in total on a flat baffle. I fail to see how the effective surface area is doubled and fail to see the benefits.

Can anyone explain the the theory behind?

This led to another thought for a DIY scenario. In a similar setup, could you phase shift the woofer(s) on back as dipole cancellation kicks in? Run them as dipole as long as speaker, placement, room allows and then slowly transition the woofers into working like (a rather cramped) sealed subwoofer.

Has it been done before?

Thanks!

[shrub0]

Maybe not an answer to your question but I played around with a dipole setup that I have.
It has two 15" subs in a folded configuration. I tried adding delay to one of the subs thinking this would increase spl due to making the dipole path difference effectively longer.

Long story short it made the system sound laggy kind of like a vented box.