2. analog
  3. 130205-2248

Eminent Technology LFT-8b in Harry's system

I recently signed up for the V.P.I. Industries newsletter, and today received my first such. In it, Harry Weisfeld reviews a Grado phono cartridge, but this post concerns one of the speakers he listed as being those he uses to listen to music and evaluate recordings through. All but one are traditional dynamic cones/domes in a box designs, only one being a planar/dipole. That planar is the Eminent Technology LFT-8b. I'm pretty sure Harry could, if he so chose, have instead as his sole planar a pair of $6000 Magneplanar MG 3.7i's, or even $14,000 20.7's. But nope, he instead chose the $2500 ET LFT-8b, imo the greatest value in a loudspeaker on the market. I compared it to the 1.7i, and the difference was dramatic.
128x128bdp24
clio09
2,978 posts
 
A couple small corrections here. The Music Reference ESL Speaker System is $12,000 including a pair of ESL panels, a pair of bass speakers, and a bass amp that includes an active crossover (4th order Linkwitz-Riley, 100 Hz high pass and low pass). The direct drive amps are extra starting at $6,500. The speaker system and amps are custom built to order.

Yes, there aren’t any output transformers in the direct drive amps so technically it is an OTL. However, they put out 5000V. Not sure how many OTLs do that, so the speaker better be up for it.

I run the original Acoustat servos with Acoustat Model 2s with panels modified by Roger Modjeski (I also have Quad ESL with Atma-Sphere M-60s, but converting the Quad to be powered by direct drive). I augment them with a bass array of 4 woofers in a biamp set up. For Roger, the 100 Hz cutoff point is important (his ESLs cut off here), as he wants to avoid male vocals creeping in to the low end, which he has demonstrated to me on select recordings he has. That’s the main reason the LFTs and their 180 Hz cutoff aren’t in my system.
bdp24's avatar
bdp24 OP
4,908 posts
 
Thanks for the info and correction clio. 5000 volts! Beware, modifiers!! I bought a pair of LFT-4’s as an alternative to my Quad ESL’s, and it CAN be crossed-over to at 100Hz (or lower) from a sub, being a pure panel / no cone woofer design. I know Roger uses an 8" woofer in his sub, so am thinking his ESL may be an excellent candidate for the OB/Dipole Sub from GR Research/Rythmik. No offense, Roger ;-) . An 8" woofer can move only so much air, and the dual 12" woofer OB/Dipole Sub is really, really good, and perfect for dipole loudspeakers. I gotta sell some of my vintage drumsets before I can spring for the Music Reference direct-drive system.
clio09
2,978 posts
 
Unfortunately Bruce won't sell the panels separately, which I can understand. As for active subs, I just can't get past the internal amplifiers they use. My Luxman M-02 might not be the be all end all in power, but for the 8" drivers Roger selected it's near perfect. The crossover is EQ'ed to 30 Hz which is enough for me.
bdp24's avatar
bdp24 OP
4,908 posts
 

The Rythmik A370 plate amp (the amp in the OB/Dipole Sub) is no ordinary amp. It is a well designed 370 watt class A/B analog amp, controlling the dual 12" woofers in a servo-feedback circuit. The front-to-back cancellation inherent in dipoles is counteracted with a 6dB/octave shelving circuit, providing response to below 20Hz at sufficient SPL for most music. The dipole operation of the sub works particularly well with dipole speakers for the obvious reason, as well as exciting one less room mode than monopole subs.

Clio, if you ever see an Electron Kinetics Eagle 2 amp at a reasonable price (less than $500 or so), consider getting it for your 8" woofers. It is a KILLER bass amp!

clio09
2,978 posts
 
I am actually looking for one now.
More to discover