Allow me to explain, and I hope my response doesn't get immediately ushered off to the industry section.
To my ears, a speaker that I design to measure flat also sounds "live", which is a bit forward to some audiophiles. To run a system this way, the treble signal must be very clean all the way to the speaker posts. And the room must be well behaved also. This is what I have in my reference setup at home.
Now everyone's preference (and room) varies. Especially in the bass. Or the treble. Because it's all relative to the midrange, right? I heard lots of different songs played over three days, and as is expected the recording quality varied from harsh to pristine. So I found the treble contour switch indispensible.
This is why the Series 5 TMW speaker system has a 3-way treble contour switch, and two bass contour switches. The treble contours are
-2dB across the entire treble band (>2kHz),
0dB (my preference), and
+Top Octave lift (extra sparkle only above 10kHz, also a favorite of mine).
By Saturday afternoon we skipped the use of line filters for the power amps, which increased the speed of snare drum, and we switched the bass to the 20Hz switch setting to lift 30Hz. (All rooms had an 80Hz floor/ceiling mode. We can’t reduce 80Hz, but we can lift the range below it.) This helped make the bass more even and full all the way up through the midrange.
But I kept changing the treble switch depending on how "hot" I thought each recording sounded. Classical would typically be -2dB, since that makes a slightly more distant presentation, i.e. as though the venue was larger. Some recordings were a little dull, so then I would flip the switch to 0. Some recordings had really great upper end extension on cymbals, so I would flip the switch to the +top octave position to bring it all out. Some recordings were hot or harsh, so I would flip the switch down.
The switch does not have to be changed on a per-song basis. It can compensate for an overly live room, or for system matching, or user preference. The point is that conditions and listeners vary so much, that it is important to have something to help out.
As for the speaker spacing and toe-in – I used a Cardas setup, but with wider spacing. All center seats in the 3 rows exhibited really solid center imaging and focus, and it didn’t matter if there were three listeners in a column! The front center seat was truly holographic and especially addicting to me, as the speakers not just disappeared but the sound stage and bloom occupied the entire front end of the room. We saw listeners sit down there, and then immediately look to their left, and then to their right as they visualized the performance!
Moving the speakers closer together and using less toe-in (as suggested by the rep) would not likely make as much difference as the treble switch. For one, toe-in really only affects sound >10kHz, while the switch is evenly effective above 2kHz. And moving the speakers apart would make them less visible and the front seat sound stage less holographic.
Anyway, Steve Fay and I had a blast at the show, and really had fun playing so many kinds of music and meeting so many nice audiophiles.
Philip Bamberg