speakers for listener with Tinnitus

There is no cure for tinnitus. Try googling tinnitus and Johns Hopkins or Mayo Clinic. Mechans is asking a question many other audiophiles should be asking themselves. Tinnitus can permanently worsen with repeated excessive exposure. My personal experience is that it is worse for a day or so if I listen at average 75 dB for an hour or two.
OSHA recommends no more than 2 hours exposure over 85dB daily, or permanently hearing loss may occur. Richard Vandersteen wisely warns listeners not to listen at high volumes.
Choosing a speaker that is detailed at low volumes is smart.
Many folks have posted that Harbeth is such a speaker, but is certainly not the only choice. My experience in this regard has been extremely positive with Harbeth, and I have two pairs. Harbeths are sometimes criticized for not being designed to handle 100dB or more, which is find disturbing as those sound pressure levels repeatedly and sustained inevitably damage the hair cells causing hearing loss.

Wilson or Magneplanar 3.6.

I think that Tompoodie is on the right track. You want a speaker that sounds good at lower db levels.
Since I recently developed tinnitus in my right ear, I'm very interested in this topic.
I’m also finding that I have a heightened sensitivity to noise in that ear. Being around loud conversation for example is much less tolerable.
I'll also say that the "metal dome tweeters are harsh" generalization isn't true (anymore). The BE tweeters on my Reference 3A De Capo's are smooth as silk.

Hi,
I've been exploring this same thing. I listened to the Magnepan .7 and they felt like beautiful, soft sounds that enveloped my ears. No aggressiveness. No ringing. 
Last week I had an amazing experience hearing the super tiny Boenicke W5. I still can't believe it. Unfortunately, at present, $5,000+ is too steep for me. 
Bruce 

Harbeth M30.1. The highs are smooth as silk and listening fatigue is extremely low. Human voice is as good as you can get with this speaker.