Gilmore Audio planars revealed

"Second, and somewhat related is the skepticism concerning the ability of our woofers to move sufficient air to accomplish authoritative bass. Cone excursion of drivers on some of the sites referred to are as little as 6mm. We are able to attain big excursions, cleanly -- plus or minus 2 inches! So our four woofers move a lot of air. To do this, "you can't use no ordinary woofer", as my grandmother would say. Not surprisingly, we haven't. It is a very unique, proprietary planar driver with a surround that allows it to function much like a dynamic speaker -- on steroids. The magnets and supporting structure are very robust. As a result, we have a woofer that is very responsive (it moves fast) while remaining very compliant (it tracks the wave form very nicely). It has a very high QTS. The four drivers share the load so they "run cool". Even reasonably high spl levels can be maintained without loss of performance. We think you'll like what we have done, unless your the jealous type."

OK, so it is now 'reasonably high' SPL levels. And you are claiming +/- 2 inches of Xmax. Excellent and unusual.

However, someone way smarter than me suggested I look at the surround of the drivers and consider whether such a surround would physically allow the cone to go in and out by 1 inch each way. Obviously it doesn't.

The high qts is also a sign of a weak magnet, which can be seen from the shots of the rear and compared to a high Xmax driver like the Adire Tumult. But that doesn't matter since bass = displacement in most universes.

Even then there is still no way 4 12 inch dipole drivers will come close to the volume you are talking about.

Unless you would like to share what frequencies we are talking about.

the speakers sound interesting but some questions aren't answered.

the speakers are described as acting like a very tall line source. a 40 inch (model 3) or 60 inch (model 2) ribbon doesn't go anywhere near from floor to ceiling. you don't say anything about horizontal and vertical dispersion. tilting the speakers back looks like compensating for limited ribbon length and very little vertical dispersion. could be the model 3 can only be listened to sitting down because of vertical beaming. and how can four woofers in one row about a foot away from the ribbon be called a line source? the distance between them creates an acoustic timing anomaly that produces comb filter frequency response. someone asked about that, no reply. how about doppler distortion associated with such long excursions? funny that the photos show no binding posts or crossovers.

i guess the proof will be in the listening. is the center channel an available option?

These speaker may sound great, but they should not be called "planar".

I'm still perplex.
And we ARE a civilised group here, I've been around long enough to know -- but I think the speaker presentation took a wrong turn s/where, despite Sellerwithintegrity's kind efforts:

Steved and Planar make excellent points about Qts and comb filter effects... and so have others.

I just still fail to see the "revolution"...
Not to say that this speaker will not sound spectacular; I LOVE dipoles, anyway. So does Steved, by the way:)

From the info gleamed from Sellerwithintegrity's posts and the pictures, and with all due respect, this *looks* like (no more than) a good passive dipole construction with a wide-band line source , & a point source array for the lower freq. -- passed @ the limit of 2pi radiation of the baffle??

However and IMO there is a lot of merit in designing a dipole with passive equalisation...

Also, designing a top-notch dipole to a cost level, has merit too.

10mm of Xmax is very good; the choice of four (parallel?) woofs explains the compromise of small magnets (woofers with big magnets like, say, the Supravox 400: Xmax: 8mm/qts ~0,4 /magnet +1,5T, cost over $600 EACH -- not the stuff for commercial offerings).

As to how they manage to have 4 high Q woofs outputting "clear" and fast sound to integrate with the low mass magnet ribbon, is a secret probably hidden in the xover Sellerwithintegrity refers to.

There's merit in that too.

The baffle shape is a quarter "heart" (hearts are reputedly excellent for dipole operation -- but think of universal waf with a heart-shaped speaker!)
So, that has been carefully thought out too.

What about the high frequencies -- over 18kHz (they're useful too)? I think that the addition of a tweet on that baffle would create, at least, phase and/or gp delay complications and filtering/equalisation difficulties. Also it wouldn't look as good (and deafen the beautifully engineered centre channel).

As Sean once wrote, I have trouble making my posts brief...

But here it is. What's the bottom line (i.e. the caboodle) for the B&G-like ribbon, the four woofs, the filter and, most of all, the hours and toil that went into finalising the design???

Gregm...If I remember correctly from Bob Carver's explanations of his speaker, the small (weak) magnets in the LF drivers are deliberate and necessary to produce dynamic characteristics needed for free air operation. (I have no idea why). So cost is not the deciding factor.