An amp will seldom overpower a speaker. In fact, blown speakers or
poor speaker performance is usually the result of underpowering them.
More power is always a good thing.
If the sound is not as bright
as you would like, then it is the speaker that is not to your liking.
Too much power from the amp would have nothing to do with it. But there
is probably something else at play here causing the treble to not sound
right. Most likely its your room, the furnishings in your room and the
placement of the speakers relative to your listening position.
I suggest you experiment with all of these factors first before you rush
out to get new speakers.
Good answer, paraneer. I'll add that the type of speaker cable you are using will affect sonics. And the impedance of the speaker cable plays a part in the sonics of amp and speaker.
Also, a stranded copper conductor will typically present smoother highs than a solid core speaker cable such as Audioquest. When silver is used as a conductor, it will bring out the higher frequencies.
What speakers cables are you currently using? You may need a cable with a broader bandwidth to get more highs through your speakers.
