Anyone try Townshend Super Tweeters?

my own speaker is ruler flat(plus/or minus 1.5 db)to 25khz

If you're -3db @ 20-25kHz the only reason to boost your hi freq is if the room is damped: the wavelength at 20kHz is very short, so average thickness material will absorb...
Assuming you want a HF spl boost, use a 1st order & cut higher rather than lower. The good thing is that the s-tweet's upper resonance will be too high (~100Khz) to be significant in the audible spectrum as its effects daisy-chain downward.
But there, you'll need a Murata or a Tad (or Townshend/Tannoy -- but they're very expensive). There is also a FOuntek s-tweet that's priced logically. The Fountek mentioned above is a normal tweet (37kHz) and will only boost your audible hi-frequencies.
Measure yr main spkrs' power rating & make sure you equalise the s-tweet accordingly. Also make sure you place it correctly on the same vertical acoustic plane as the tweet while you're at it -- or you'll be out of phase with the tweet!
Cheers

Sirspeedy- I'm not sure it's overkill, I'm just wary of the cost-benefit.
Yr room treatment obviously addresses reflections (you mention "glare"). By adding a s-tweet you'll be adding HF sp on axis & (assuming a ~30degrees dispersion) and some reverberant sound as well (you'll effectively overcome part of the room treatment): so, you might perceive more "air" and HF harmonics will be more pronounced, even at low volumes. From yr description, you don't need a s-tweet for high volume listening.

This may be useful for cd as there typical response peters out after 10kHz or so -- the energy level falls.

TO put things plainly, the advantage of a s-tweet is that its response limit is so high up that the audible HF are well within its linear region. The disadvantage is that it won't play as low as a regular tweet... Most spkrs start dropping in room, around 10kHz or so, & a s-tweet will cover +10Khz easily (and that's audible).
Best thing would be to borrow one -- possible? Try at low AND high spl. Cheers

Eldartford, I don;t doubt yr disc player measures flat on a sine & yr maggies likewise. Try (if feasible) to measure response (FR + PR) on a musical signal at listening position in room & compare to what's on the storage medium -- say the cd in this case.
As to your ears, they are possibly "sensing" a combination two things. 1) that there is info beyond 14kHz (which is what you note, so I'll take yr word for it), because, 2) there is no steep/sudden barrier/filter/drop over 14kHz -- i.e. the sound continues even if yr accuity drops.

People listening to linear extended HF reproduction find the sound "softer" than when there is a sharp roll off within the audible range. Cheers

ELdartford... that's a good thing. Losses are usually visible (slightly, but still). You must have equalised yr reproduced sound very well!