Recent content by Jazzman53

When I say that a RiPol (or any other dipole) doesn't thump you in the chest, I mean that it doesn't pressurize the room cavity to the extent that a monopole does. The same characteristic makes a Ripol less prone to exciting the room's resonance (i.e. it's not boomy sounding). Any woofer not...

I'm not equipped to measure its sensitivity so I can't tell you what it is. Like all dipoles, Ripols are progressively less efficient with falling frequency due to the dipole phase-cancellation. If you prioritize clean, articulate, non-boomy bass over efficiency, then I think a RiPol is a...

Absolutely! . The Ripol's compliment the OB mid-bass drivers perfectly. The combo is non-boomy and clean and tight like I had never experienced before.

It's a psychosis and I'm an enabler so go for it: https://jazzman-esl-page.blogspot.com

I've never had an opportunity to hear the big Soundlabs. The big ones are huge compared to other commercial offerings, and physics tells me their sound has to be really BIG. Someday...

I don't know who came up with the copper foil charge ring idea but it's a good one, and it's been used by DIY builders for many years, including all of my builds since 2008. Vapor-deposited indium-tin oxide may be the current state of the art in diaphragm coatings, but that process isn't...

Sanders' Ultra-Stat white paper states that his diaphragm coating is "embedded within the material". Neither Sanders nor ML discloses what their coatings are but I'm guessing both are using plasma-deposited indium tin oxide, which should be a significant improvement over whatever ML was using on...

I will concede that I have no experiential evidence for Quad panels specifically. It may be that Quad uses a coating so robust that it never goes bad. That seems to be the case with the carbon-black coating that Acoustat used. There is ample evidence of the coating on ML panels losing...

It's buyer beware when buying a used ESL. Too often the seller knows there's a deterioration in the speaker but sells it anyway, before it stops playing entirely, with no regard for the unwary the buyer who gets stuck with a lemon. An ESL's Achilles heel is its diaphragm coating losing...

I don't disagree with that, but when you need a bus (guests drop by), a race car won't do. Maybe a convertible? (a segmented ESL with switch-selectable wide and narrow dispersion modes): http://jazzman-esl-page.blogspot.com/2008/03/a-segmented-wire-stator-esl-with.html Those were butt-ugly...

I was an ESL builder for many years, and I concede that I've become quite opinionated about what I think works, and doesn't. My first ESLs were hybrids, with the woofer in a transmission line enclosure, and a perf-metal stator, flat panel ESL. These beamed like a lasers but sounded great in...

This isn't specifically the Quad approach, insofar as it's powered thru an RC line rather than an LC line, but it's a symmetrical 15-segment (7+1+7) quasi-line source panel with good dispersion and it sounds pretty incredible. Full details here: https://jazzman-esl-page.blogspot.com

Here's some more directivity sonograms comparing an unsegmented flat panel, a 30-degree arc curved panel, and a symmetrically segmented panel. This came from a post by Steve Bolser on the DIY Audio Forum, which I copied on my website.

I stand corrected... you are right, the Quads did use electrical segmentation with concentric ring conductors!

Curving the panel is one way to mitigate beaming. It's not perfect insofar as it introduces some drive asymmetries, but it's effective without addiing a lot of complexity and cost. Another method sections a flat panel into a narrow treble section and a wider mid/bass section, each separately...