But howDid your mind's eye try and fit 8 x 8" drivers onto the oval to go blind? "With Liber|8, I'm trying to solve two issues. The first is my longstanding complaint of the 21cm Enviée's whizzer. It's the one element that doesn't work for me. To my ears it goes acidic in the upper mids as though it's off key particularly on female voices. It's the same issue Cube Audio solved with their triple-whizzer concept. Now I have high hopes for the 11cm Enviée of the Vox 3a. It can do without a whizzer. Armin always maintained that his 16cm widebander betters the 21cm and I agree. So using 2 x 11cm not 21cm widebanders, all will fit as shown in option 1. Should the mids go a bit lean, I can easily revert to one 11cm and one whizzer-less 21cm as shown in option 2."

 

"The other issue relates to Libération. From experience it works fine up to 30m² but in bigger rooms, bass takes a dive. Prior to Munich last year I'd already tried a kind of Ripol version with six Envieés. But it all went very flat mainly in the upper bass and lost that forward projection of the sound."

"A few days ago I had one of those 5:00AM moments. I hadn’t really checked yet how many 21cm woofers I could fit on that Liber|8 baffle: eight! That's 1'864cm² of cone surface, more than 2 x 15". So perhaps a 2.1 system where the pure bass baffle becomes option 3 would do the trick for big rooms? Time will tell."

For a demo on how to bend solid wood not with his regular guy, Martin had this:

To segue back to dipole bass, the acoustic short of low bass canceling out is the concept's inherent limitation. No free lunch. Like other solutions, OB has pros and cons. Informed listeners cognizant of their priorities choose accordingly. In my experience with big Ripol subs in bigger rooms, without compensation none had yet really cracked the 30Hz barrier despite bringing up to 2×15" woofers per channel. That's in stark contrast to KEF's diminutive dual 6.5" KC62 which exploits 1'000W class D, motion feedback, DSP and an aluminium enclosure. On reach vs size, box bass exceeds dipole bass. Ditto for power efficiency due to free room gain. But it's not really free. 360° radiation pays heavy with temporal blur and overhang. It activates room modes to add amplitude distortion to time distortion. A Ripol's lateral nulls and reduced rear output don't. Bass starts and stops far more precisely. In basic terms, it's about quantity + efficiency versus quality + inefficiency.