Help, too bright

Stands positioned well away from reflective surfaces will help a lot. Play with the toe-in angle and distance to the rear wall.

BTW, fancy cables can make your wallet thinner and more comfortable to carry, but if they audibly change the sound of your system, there's something wrong with the cable design.
Good cables are electrically neutral, well sheilded, have good connectors, and cost about $20.00

1. MP3 is not a high fidelity source and should not be used for critical listening.
2. Interconnects that come with your equipment should not be used. For cd player to amp suggest you try MIT, Harmonic Tech or if you're on a budget, Phoenix Gold 810 (from Parts Express). Avoid the cheap AR cables recommended by Stereophile.
3. Radio Shack speaker cables should be replaced. For low cost, try Canare Star Quad available from Markertek or the CL-3 Monster cables from Parts Express. Search the forums for more info. Even a good ofc copper based 12 gauge cable will probably work as a starter solution.
4. Good speaker stands will improve the sound.
5. After trying all of the above, if your system still sounds brite, suggest you investigate the AH! LS Noise Killer filter for your speakers.

try virtual dynamics cables. the life they will bring to the music will amaze you.

No...it's the TREBLE-cut that they take FROM the music that may help that particular recording that may help Threetwo.... That's what lots of magnetic material (steel shot, in this case) does as a field medium around the electrical core.
Cheapest out for ThreeTwo is to install nice cheap neutral CANARE starquad mic ICs and star-quad speaker cables and relisten to several CDs, and then do spectral tilting with room placement/damping, IMO.

I've reduced brightness several ways: transport, power cord, cables & interconnects, power conditioning, tubes, toe-in and sound absorbing gear.

I had very good improvements going to a tube preamp.

I had amazing, jaw dropping improvements by changing a transport.

I heard night and day difference between interconnects. IMHO, if neutral cables were easy everybody would have them. I find cables to make a tremendous difference. Try borrowing some cables/wires and see if it makes a difference. If so, go to audioadvisor.com and look at their discounted audioquest or kimble kable gear (not that this is better than Cardas or other wire). I've frequently heard Cardas can tame a bright system but don't have experience with them. Anyway, if the cables are the problem, then it's an easy inexpensive solution. I'm suspicious about your wire and cables.

On the other hand, some gear is made bright (like my previous Adcom or Micromega gear). Try switching out components with friends and see if you can find the culprit.

Recently I found a stock power cord to have a larger impact on sound than two different expensive DAC/filter combos. This in comparison to an inexpensive DIY power cord design by Crump. Two of us were comparing gear and felt one set was brighter than the other, until we swapped cords, and suddenly it was the opposite.

Less or zero toe-in should sound less bright at the sweet spot, but worse in the rest of the room.

Sound absorbtion at the first reflection point on the side walls can help a lot. Also, add carpet and wall hangings if you're in a bare-walled sheetrocked room with wood floors.

Good luck.