What is the best way to tame a slightly bright speaker?

Thanks jtcf,  Yeah my room definitely needs some work.

Thanks everyone for your replies. They are varied as one would expect.

My room is far from ideal, but I don’t think it’s having a major impact on this problem. The listening area is carpeted and has a fabric sofa and chair and the house has an open floor plan, so I don’t think it’s excessive reflections. This suggests to me that maybe subwoofers would help.

I do agree that room treatments could improve and maybe eliminate the brightness, but that would probably be the most difficult way to attack the problem. It’s something I would like to do over time, but it will require a lot of time and expertise.

There have also been suggestions for cables and the controversy that comes with them. I’m using Analysis Plus Clear Oval speaker cables. Don’t let the name fool you, they’re not bright cables. I don’t know how they came up with the Analysis Plus name, but they’re just good quality copper cables using their proprietary oval construction methods (to reduce skin effect, according to AP). When I get the right gear together I want to experiment with cables with The Cable Company, but I’d rather not try cables at random, unless someone has experience with these particular speakers.

That brings us to upstream gear. The D’Agostino Classic Stereo that I have is a powerhouse amp, 300 watts at 8 ohms 1,000 at 2 ohms according to Stereophile. I don’t need that power with the TADs and changing amps would probably be a good place to start. Would a Class A amp like a Pass or Plinius or Accuphase relax the mids and highs a little or just give me different sounding bright speakers? I don’t think the D'Agostino is a bright amp but I haven’t heard it described as laid back or refined either. Tubes are another option. Any suggestions for a change of amps?

Thank you everyone for sharing your ideas and experiences.  There's a lot to try in your suggestions and I'm sure something will work.  For fellow Evolution One owners, yes they are really good speakers.  I'm looking forward to getting them sounding their best (or close anyway).

Thank you again everyone.  Don't worry, I'm not going to try to replace parts in the crossover.  I'm not saying that those who suggested that are wrong, it's just that  I don't have the skills required.

I  am trying the simplest, least expensive solutions first and I'm making  progress on that front.  So I have plenty of ideas to work with.  I'll get it sorted out.

Thanks everyone for all the good advice.  I have tamed the brightness and agree with  Kal Rubinson that the TAD Evolution One is a marvelous speaker.  I am definitely enjoying it.