Dual Kef B139 (Coffin) Woofer


A design I first saw in the Fried Model H was the "coffin" woofer. Fried used an OEM version of the Kef B200 -- the DIY community often used the Kef B139. Essentially two single fold lines laid side-by-side with woofers firing out either end.

The picture here and the plans are from the
Perfectionist Audio version (I choose this one because the web site has detailed construction information & more pictures). I have plans for one I built after seeing the Fried H which except for some dimensional differences is essentially the same. Since the B139 is very hard to come by these days a suitable pair of 10" or 12" drivers could be assembled into a suitably modified version of this box.


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