Steve Guttenberg finally reviews the Eminent Technology LFT-8b loudspeaker.

@harryz Hi Harry, just a reminder that the cable compliment is very different between the 8b and 8c. In the 8c, it is a set of line level cables from preamp out to the DSP / woofer  units, then another set of line level cables from the woofers to your amps, and finally speaker cables from amps back to the speakers. The amps only drives the mid range panels and the tweeters. And all signals go through A-D and D-A conversion before it goes to your amp. 

Regarding the 3 db differential in your speaker output, if you are dealing with vinyl playback, then I'd check azimuth. If not analog, I would still check the output of digital source component. My vintage Wadia CDP experienced a L-R imbalance which got fixed.

Thanks ledoux1238-

I don’t have the 8C woofers yet; it will be about six weeks. I’m pretty certain it’s the speakers because I’ve checked everything else and I’ve tried various sources. I’m playing my quad ESLs now with no issue. I’m going to measure the output and impedance of the 8Bs to see what’s going on.

Overall, I prefer the 8B to the Quads but it’s pretty damn close-:) They both do different things really well but the 8Bs are more dynamic and more full range. And still, it’s hard to find fault with the Quad’s naturalness and glorious midrange…

@harryz: have you tried disconnecting the woofers and just evaluating the volume from the mid/treble panel? How about vice-versa? Are the impedances equal, R-L? And I assume you've swapped speaker cables R-L and the 3dB drop is still present on the same side? Last, have you panned the balance R-L and found the same imbalance?

I am a super freak.....er....I mean..super tweak....he he.

You REALLY WANT to upgrade ALL the crossover parts, jacks and wiring in these things.......The speaker posts, caps, wiring and coils are NOT serious stuff. Change the posts to Nextgen WBTs.....change the caps to best Clarity, Mundorf, V-Cap, Jupiter copper, other copper caps, etc....bypass with smaller values for more speed and clarity. Make sure you put the outer foil of the cap to ground or to the load (speaker). Change all coils to copper foil wax paper 12 gauge Jantzen coils. Make sure you go "into" the inner winding of the coil....and "out" the outer winding. Change the wires to VH Audio, Neotech Litz or other great wires. If there are any resistors in the xover then change them to Path Audio resistors or the latest Mundorf’s....or power Caddock’s bypassed by a nude Vishay. The difference will blow your mind.

I would not use the DSP in the C version on the panels......just for the woofs. I personally would get the B version and make a baffle next to the speaker and use a couple of 12 inch Acoustic Elegance dipole drivers on an open baffle......and then get a separate crossover/amp to drive them. These are the same drivers used in the $120K open framed IO speakers from Italy that Jason of AudioJunkie fame went crazy over.

https://www.youtube.com/watch?v=WqueX42qRf0&t=163s

So Ric (@ricevs), you’re no longer a fan of the GR Research/Rythmik Audio OB/Dipole Sub? That too can be used in place of the stock LFT-8b woofer.

The 2-woofer version of the OB Sub kit is available from Rythmik for $999, and from GR Research with the required OB H-frame (in flat pack form) for $1660. Both prices for one sub, two required of course.

If you can build your own H-frame (or the smaller W-frame), a pair of the OB Sub kits will run you $1998, about $400 more than the pair of LFT-8c woofers. The difference between the two is the Rythmik/GRR is an open baffle version of a dipole sub---with two 12" woofers, and the LFT-8c has a front-firing 8" woofer and a rear-firing 6.5"---in a sealed enclosure. Both are powered, the LFT providing DSP not included in the OB SUB. But the Rythmik plate amp does provide all the controls necessary to mate the OB Sub with the LFT-8b planar panel.