GR-Research Line Force First Transparent Speakers?

For those who don’t know, the discontinuation of the original B-G NEO drivers (the NEO 3, 8, and 10) put an end to the availability of the GR Research full line-source magnetic-planar model kit (which @jaytor has just completed building), as well as the factory-built version of same by another company (whose name escapes me at the moment). Danny Richie was therefore forced to design line source open baffle models using only a single NEO 3 tweeter (which Danny has made for him) and multiple 6.5" dynamic drivers (optimized for open baffle use) for midrange and bass: the NX-Treme and the NX-Otica. Open baffle subs are used to make the models full-range ob loudspeakers. As Wendell Diller of Magnepan has for years been insisting, monopole woofers just don’t work with open baffle and planar loudspeakers (as @jaytor found with this Tympani/Entec pairing, and as did I when I had a pair of Infinity RS-1b’s)

While I have no doubt the NX-Treme and NX-Otica sound fantastic, I’m a hard core planar purist, and dynamic ("cone") drivers just don’t do it for me (though I admit I’ve never heard a line source employing them). Danny is very complimentary of the open baffle designs of Clayton Shaw of Spatial Audio, though he isn’t a fan of wide, flat baffles, choosing to go with "folded" baffles (watch the GR Research YouTube videos to learn why that is).

With the NEO drivers no longer available, I chose to stick with my planars (Tympani T-IVa, Eminent Technology LFT-4 and LFT-8b, and QUAD ESL), mated with the GR Research/Rythmik Servo-Feedback OB/Dipole Sub, a 2-woofer version of the 3-woofer sub seen in @jaytor’s pics above. One of the LFT models mated with the ob/dipole sub is in a way a modern version of the Infinity RS-1b, but without the problems of the Infinity EMIT and EMIM drivers (the ET LFT magnetic-planar drivers are far better built than were those Infinity’s, as well as the Magnepans for that matter), and with the far superior ob/dipole subs in place of the Infinity monopole woofers. If you already own a planar or open baffle loudspeaker you love, but want or need more or better bass, do yourself a huge favour and look into the ob/dipole sub.

By the way, Magnepan is hard at work preparing a new model that is to include dipole subs, and the sub will be made available separately for use with their other models. And Eminent Technology has just introduced the LFT-8c, which uses a dipole (though NOT open baffle) woofer in place of the omnipole woofer of the LFT-8b. The dipole woofer is available to current 8b owners, who can simply remove the LFT panel from the "b" woofer enclosure and bolt it on the new "c" dipole, for full range dipole music reproduction. A new crossover is included, which includes DSP and EQ, and a power amp for the woofer. $1500/pr. Imagine how much Wilson and/or Magico would charge for them ;-) .

Awesome @jaytor! I’m green with envy :-( . And I’m only a half hour or so away from you ;-) . I know of a few guys who replaced the magnetic-planar midrange driver in their Tympani T-IVa loudspeakers (which I own) with six or seven NEO-8’s. The NEO-8’s fit right in the slot the stock Magnepan driver sits in, and the owners feel the NEO-8’s provide a significant improvement to the T-IVa. But 12 or 14 NEO-8’s (when available) cost more than I paid for my T-IVa’s!

You still have your GR Research NX-Otica’s, I presume? With the OB/Dipole subs, of course. Glutton ;-) . I’ve been telling everyone about the sub for years, but you can only lead a horse to water. I suppose many are afraid of doing a simple DIY build of the H-frame the sub kit gets installed in, but anyone who did Jr. High or High School wood shop is up to the task. If I can do it, just about anyone can! I went with a W-frame (rather than an H-), and two of the 8 ohm drivers (rather than three of the 16 ohm).

Danny Richie designed his own version of the NEO3, is having it manufactured to his specs, and using it in some of his designs. He is currently working on his own NEO10. The NEO3 magnetic-planar driver and all his kits are detailed (with prices) on the GR Research website.

And for anyone who hasn't heard, DR has made a series of very informative videos on the subject of loudspeaker design, viewable on YouTube. Watching them will make you a smarter consumer! Also worth your time is to read through the GRR AudioCircle Forum. SO much info, a free education in loudspeaker design!