Considering a POSSIBLE replacement for speakers. Opinions?

@noble101: Tim, give Danny Richie---the designer of the OB Sub---a call at GR Research. He is a very nice guy, and will be happy to advise you on adding the sub to your system.

Danny is one of the true experts in the world on the subject of OB speaker/sub design. Also check out the GR Research Forum on AudioCircle, which has a number of threads dedicated specifically to the OB Sub. 

@mijostyn: Ah yes, but there is a cure for the one weakness in the ET LFT-8b (ignoring in this discussion it's inefficiency, which is actually not as severe as are Maggies. I have both.)---the matter of mating the planar m/t drivers with a monopole bass driver (woofer in a sealed enclosure), good as the LFT-8b woofer is (much better imo than in any other hybrid.): use the GR Research/Rythmik OB/Dipole Sub in place of the ET woofer (which has it's own binding post on the top of the woofer enclosure---to facilitate bi-amping or bi-wiring, and may be left unconnected).

The OB sub is, like any and all planar loudspeakers, a dipole radiator, with a figure-of-8 radiation pattern, a null to either side of the OB frame into which the dual-12" woofers are installed. It shares that pattern with the LFT-8b planar drivers, eliminating the problem of the spl-drop off with distance differential found in "normal" hybrids. Clever, ay? ;-)

The GR Research/Rythmik OB/Dipole Sub can be used up to 300Hz, safely above the 180Hz planar/dynamic-to-woofer x/o frequency of the LFT-8b. A single sub (containing a pair of 12" woofers) may be employed on each channel (left and right, in stereo), or multiples may be stacked up on each side. Choose the number of OB Subs based on the desired maximum-spl (and available funds ;-) .    

You have a lot of good choices. The Magnepan LRS with a pair of subs (especially the GR Research/Rythmik OB Sub) is a good one, the Maggie-killer Eminent Technology LFT-8B an even better one. VPI’s Harry Weisfeld considers it to have the best midrange he has ever heard, regardless of price (I compared the LFT-8B to the MG1.7i---no contest). But both those options require spacing of at least 3’ from the wall behind them, 5’ even better.

For a monitor plus sub(s), I know what I would do: Posted just today here on Audiogon is a pair of GR Research NX Studio Monitors, custom made by a private speaker builder from the GR Research kit (the only way the speaker is available). The seller has priced the speaker at the cost of it’s parts, so not only do you not have to build it yourself, the cost of him doing it is.....nothing! Add a pair of subs (again, the OB sub would be optimal), and you have a really, really good loudspeaker, at a very modest cost. But this speaker also requires 3’ spacing, as the NEO3 magnetic-planar tweeter is employed in open baffle/dipole fashion.