But howDid your mind's eye try and fit eight 8" drivers onto the oval to go blind? Mine did. "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 the boys at Cube Audio managed to solve with their triple-whizzer concept. Now I have high hopes for the 11cm Enviée of the Vox 3a. That 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 they work fine up to 30m² but in bigger room volumes, 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 and thought that I hadn’t really checked  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 but not with his regular guy, Martin had this:

To segue back to dipole bass, the acoustic short of low bass canceling out is the inherent limitation of the concept. There's no free lunch. Like other solutions, OB has its pros and cons. Informed listeners cognizant of their own priorities choose accordingly. In my experience with big Ripol subs in bigger rooms, none really cracked the 30Hz barrier despite bringing up to 2 x 15" woofers to bear on each 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 for -3dB/11Hz reach and 105dB max SPL. On raw reach relative to size, box bass far exceeds dipole bass. Ditto for power efficiency due to room gain. The same room gain from 180° radiation—it's maximized by corner placement—causes blur and overhang. It activates room modes and reflects from all our boundaries. A RiPol's lateral nulls and reduced rear output don't. Its bass starts and stops far more precisely. In the most basic terms, it's about quantity/efficiency versus quality/inefficiency. It's why in parallel to the Liber|8 concept, Martin had begun working on a 2×15" RiPol subwoofer concept.

… to be continued…