I have had a pair of NSMT speakers for more than a year and find them to be very good. It took me a while to understand the design, but it sounded good in my room, better than other options in my range—under $6,000.
I was set on a stand mounted speaker, and found little compromise in frequency response. I think some of the claims, and you can find silly claims from almost any maker, can be confusing because they do seem to be impossible. I've found that mine claim time coherency, but I've come to realize that time coherency for any design can only be accomplished in a small area, and that my speakers can't be perfectly time coherent as designed. They are minimum phase though, just as advertised, and the crossover is minimal—cap and coil.
What appears as an MTM design is really a ported three-way. It uses variants of the same 6.5 inch SEAS TPX driver. One driver is made to be sealed in an acoustic suspension box. The other appears to be the same driver but has a different magnet, tuned to what I suspect to be semi-ported design. This driver, I suspect, runs full range while the acoustic suspension driver gets the coil. Now I may have this wrong, but it does explain how a design can be transmission line and acoustic suspension, both.
Errol Rickets is the designer. He's a nice guy, and I feel like I got an amazing deal. I would not hesitate to audition any of his speakers. I think he has some very creative solutions and also puts lots of ear-tunning time into his designs.
