FYI: here is the review I wrote about
It's a test of a complete system with 683, HTM61, 685 and a B&W sub.
This review concludes with the exact same thing I experienced with the HTM61. Too bad I didn't read this review before AFTER I bought it and had realized it was so bad compared to the DM683 alone set up with mm accuracy in a likesided triangle with the resulting seamless stereoperspective where the speakers could not be localized and all instruments and elements in the soundfield placed accurately in between (this also includes voices nailed in the middle in movies)
which of course is only valid if I sit in the sweetspot, and thats why I had to get the HTM4S.
"At the Movies
I'd like to say that this aspect of the B&W's performance was glitch-free, but it was not. The final result, as you will see, turned out fine, but not with the configuration I had planned on.
The problem was the HTM61 center channel speaker. Despite the pedigree offered by its FST midrange, it blended poorly with the left and right 683s. Its sound was thicker, duller, and less open—a characteristic that was different depending on whether I was seated on-axis or off to the left or right by about 30-degrees (it was also different in the two directions). This not only reduced dialog intelligibility but also significantly reduced the "jump factor" of the whole system in full surround mode. Yes, the HTM61 was stand mounted below the screen, which placed it less than two feet from the floor/ But that position has worked well with innumerable center channel designs that have lived there before.
What the measurements will show remains to be seen, but a few basic in-room measurements indicated nothing obviously defective about our sample of the HTM61.
When I substituted the similarly priced Revel Concerta C12 for the HTM61 the soundstage and clarity opened up considerably. In fact I lived with that setup for a couple of weeks as I reviewed other gear and movies on the system.
But that setup was hardly appropriate for this review. So when I got down to serious business I tried something else. The vital front channels and the subwoofer, of course, had to be all B&W. So I pulled one of the 685s from surround duty and pressed it into service as a center channel. But this did leave me without a matched set of B&W surrounds. So I used a pair of Revel M12s, a very similar two-way, stand mounted design, as substitute surrounds (and only slightly pricier than the 685s, at $698/pair). This did not, in my judgment, affect the overall sonic performance of the system significantly, and I had already determined that the 685s can do an excellent job as direct-radiating surrounds. "Comments on the measurements they made (the curves are in the review)
"The averaged response of the HTM61 (violet curve, Figs. 3a and 3b) shows a significant dip from about 2kHz to 7kHz, making the speaker a poor spectral match for the left and right 683s. While bench-test results don't always correlate with listening tests, they do here. The lack of presence and voice intelligibility I heard could almost be predicted by the frequency response. However, the HTM61 is more uniform from 66Hz to 1.6kHz (+/-1.3dB) than the 683, even though the two speakers use the same midrange driver."