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


I know the answer is get a speaker that isn't bright,  but I've got a pair of TAD Evolution Ones that I like quite a bit except that the magnesium midrange and beryllium tweeter are just a little bright for me.  I'm driving them with a D'Agostino Classic Stereo, which I needed to drive my old speakers but I don't need all that muscle for the TADs (89db sensitivity, 4 ohm impedance {doesn't drop below 4 ohms}) recommended power 50 to 250 watts. 

I'd like to get  an amp that does voices especially well.  I know somebody posted recently that a subwoofer solved his brightness problem and I may look into that at some point.  Any and all suggestions are welcome.
128x128tomcy6
Tubes were the biggest improvement in taming my 801Ns.  Made the mids and highs much more listenable to me.  I still use SS muscle for the lows tho.

Bill
What geoffkait said may sound funny because he is that way some of the time. But that is a real possible solution. I have used that method and it helps out a noticeable amount. Geoff probably knows why, but it has worked for me. If you do it, get some that are cotton or wool, preferable wool and get a neat design, It can look good on there with a neat design. Geoff is not only funny 1/10 of the time but he is practical about 1/10th of the time.  
If you don't have time or funds for room treatment pick up some 100% wool at fabric store. Cut inside diameter in rectangle form and make 3 or four layers. It may not be pretty but in my experience it smoothed out highs and improved imaging. I mounted it with blue tak.

If you want to see without as much work with rectangle cut out. Go to drum shop and buy dense felt cymbal washers ( they go under and on top of cymbal on cymbal stand, much better quality felt than at fabric store)cut into four pieces and blue tak around each tweeter.

If you want to experiment with tube components investigate tubed preamps.A smooth,warm sounding preamp such as Conrad Johnson units for example might add just enough sweetness to tame that brightness.Then experiment with various tubes until you get your system tuned to your preference.