Speaker placement for brightness control.

Thanks for these informative responses. I don't really understand the technical causes but if I can discern a difference, it must be a somewhat significant one.

Steuspeed, I do have two ways (Jamo Concert Eights) and turning them upside down to increase the elevation of the tweeter never crossed my mind. What a good idea. If I had thought of it maybe I could have saved the cost of new pedestals. It wouldn't have raised the speakers high enough, though, to clear two pieces of furniture which was the original goal of raising them. The improvement, then, was accidental on my part.

some have used felt around tweeters to tone them down a bit

I have done this myself and it worked, though a bit too much for my tastes

something to consider for cheap

Broadstone.... I feel for you since I too have Hyperacusis. I'm very happy with the sound of my system, but my tower speakers have metal tweeters and sometimes can cause some killer pain from high frequencies.
I can only suggest what I've tried and it's been very successful, but there will always be certain CDs that I can't play. (LPs are much more kind).

I tried many different speaker cables (as you probably have) and am using 2 different cables in a double-run configuration. Cardas for highs, which sound smoother and rolled-off. But the biggest improvement was to use a lot of room treatments for standing wave absorption. Acoustic panels on side and rear wall and a tapestry hung behind my listening position.

Raising the speakers sounds like a good idea, but what is your room treatment situation?

Why don't you try a single-driver Fostex speaker? Many companies make them. Removing the tweeter might help your situation considerably. They work best with simpler acoustic music, which may or may not suit your taste, but that's another story. I have a pair that Fritz did for me with the 4" drivers and they really sound nice.

These responses are very much appreciated and I will attempt to explain further what I have done. To begin with, my present setup consists of a Shanling S100 solid state CD player, California Audio Labs tube DAC, Rogue Audio Shinx hybrid amp, and two pairs of permanently A/B'd speakers. For many years I have used the Martin Logan Odyssey hybrids and, recently, added a pair of Jamo Concert 8's on a permanent A/B switch between the two.

Both pairs of speakers are very good and I recently added the Jamo's because they are more efficient than the Odysseys allowing me to listen at lower volumes while maintaining detail and tight bass. This particular model by Jamo, btw, is incredible in almost every way.

Probably the biggest single improvement came with the addition of the tube DAC but close behind was increasing the speaker elevation. As a matter of fact, of the things I've tried, these two changes were the only ones that I could detect any resultant improvement. Between these two things, I'm enjoying my system more, although I know I'll never get back what I've lost over the years to compromised hearing.

As far as room treatment goes, because my listening room is also our living room, my options are limited. The room is 15' by 21' with the entertainment center placed against one of the short walls. Furnishings include a large area rug over wood floors, 18' of curtains on one long wall and a lot of upholstered furniture. Even when the floors were all wood, before my hearing became so messed up, this treatment, though a compromise, worked well for me.

Lowrider, I'm especially glad to hear from someone also afflicted with hyperacusis because at least someone out there understands the effect that this condition has on critical listening and, to a lesser extent, every day function. Mine is accompanied by very loud ringing at more than one frequency somewhere between 5 and 7,000Hz, according to the audiologist. It seems that tinnitus and hyperacusis often go together. I've found a couple of hyperacusis forums but never one associated with HiFi listening; if you know of anything like that, please let me know.