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
I think that either the speakers or the amplifiers may be bright sounding, however I wouldn't start by replacing them. An overly simple solution might be to fit a small piece of foam over the tweeter, one where you could add a piece of cloth over it to increase it's ability to reduce the amplification. 

Not pretty but not expensive and not permanent and adjustable to your liking. 
I feel the best bet to tame a slight bright issue would be to try smoother sounding cables. There are so many to choose from. You can try interconnects or speaker cables. For me, I find anti cables sound smoother and not as bright as many cables out there. 
Buy a nobsound volume control . I guarantee your speakers will not be bright once installed . 
@tomcy6 I use a BAT 51se for my preamp. I think the sound is just slightly dark, and would offset a pair of slightly bright speakers. I found mine used for about $3K.
I have very revealing speakers that tend to sound bright with substandard recordings. I bought a schiit loki  and it works very very well.  For $149 it’s definitely worth a try.Also you could maybe try swapping out the diaphragm for a non-metallic diaphragm.Also some people mentioned padding  down the crossovers and others cautioned against it. I would definitely try it just record the values of the stock configuration that way you can always put it back. 
It is very easy to change the balance and dynamics of the system with loading the source component. It is much like loading a MC cartridge properly.
I have the Tortuga LDR attenuator in my preamp which allows loading on the fly and I can dramatically change the overall balance and dynamics by changing the input loading while listening.lower input impedance softens treble and has an impact on dynamics. Higher impedance has more treble registers but can get wiry.
The bottom line is that you can alter the system to an optimal state for your source Zout / cables / Zin and get an optimal state. A lot of "Bright" speakers are simply faster and are better at revealing these imbalances.

this is pretty easy stuff and should really have been included in any high end component.
you can tinker the crossover.  Use paper in oil caps for the Tweeter and midrange.   Metalized poly caps are kind of bright especially when it comes to Mag and Be materials.  
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.
best way to tame a bright speaker, is with a true analog source, preferably tape.   1/4" tape at 3.75 IPS will tame any bright speaker, or if you prefer 7.5 IPS.
You say don’t say this, but it has to be said:  Fix the problem where the problem lies...if you think your Speakers are bright, why do you want to put bandaids throughout the system?   You’ll sacrifice everything you do from that point on because it’s all based on the fact you don’t like your Speakers.  As soon as you say that you still like your Speakers and throw the word but/except, then don’t say there’s a problem with the Speakers.  What you’re contemplating doing would be like buying a car based on which tires you want to have...
The TAD Evolution Ones played everything from audiophile recordings to low-bit-rate Internet radio with aplomb and authority. Teamed up with neutral electronics and a room not excessively damped, they should provide the buyer with richly musical enjoyment for years to come. It's easy for me to say that the Evolution One is a marvelous speaker—I found no fault with it.
Read more at https://www.stereophile.com/content/tad-evolution-one-
loudspeaker-page-2#Kldbk8yOxJU2XRPw.99

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.
If you want to tame your bright sound and beautiful voice out of it.

You may try out Line Magnetic 508 or 805 SET amplifier (48W).

Stock tubes are not bad.

But after some tube rolling, it is an excellent amplifier to drive high efficiency speaker.

https://forums.stevehoffman.tv/threads/new-line-magnetic-508ia-integrated-amp.542333/page-36
I actually disagree with the notion that a properly integrated sub can't make the tonal balance of a system better and in some cases much better. I have the same issue in my system of "bright" treble and when I introduced a REL sub and worked with it for awhile to make sure it was properly integrated, the tonal balance in all frequencies was much better and much more natural sounding. Sometimes the illusion of bright treble is just that - a tonal balance in the speakers that perhaps is lean in the mids so it brings attention to the highs more. 
gawdbless+1
tomcy6 If you are kind enough to tell how you tamed it, as everyone here has tried to help you, you maybe helping someone else
@clarinetmonster2, I totally agree. Well said.

Adding body and warmth to the sound naturally balances the sound.

It's a win win situation with no sacrificing of resolution as proposed by other suggestions.
Wow!  Some very amusing ways to fix a simple problem listed here.  Does your playback software contain a graphic equalizer?  If so attenuate the frequencies between 15k and 20k  two or three db.  That will fix it.
I’d cut out pieces of foam and blu-tak them to my ears.

All kidding aside, if you live in Colorado you can try out some Analysis plus cbles that I have and see what you think