I heard the DeCapo I at a dealer, using a tube amplifier which was unknown to me. I found the speaker to have a bass response which was surprising to me for its size, a seductive (although I am not sure how smooth it was) midrange and highs which I felt ranged towards the soft and lush rather than brilliant and shrill. I would suggest swapping out the Siltech cable temporarily, as silver cable tends to be bright. You could try a very inexpensive cable such as Kimber PBJ between CD player and amp. I find that the connection between CD and preamp usually doesn't require an ultimate megabuck interconnect anyway. If you don't get any improvement, consider a temporary change in speaker cable A good choice for speaker cable is Kimber 4TC. Borrow these, if possible or buy (and possibly resell) at a good price so you don't lose money if you have to resell. Whether these cables will match your system perfectly, I can't tell you, but if the problem is your current cables, this test should tell you.
I somewhat agree with those who suggest you look at placement and room issues. This could be a problem, but as you describe the problem as something which seems quite severe, I am tending to look elsewhere. I agree with making sure that the speakers are not pointing at you, but at (imaginary) persons sitting on either side of you. As reported earlier, if the toe-in of the speakers is not correct, this is one way in which you can get the results which you are currently experiencing.
I somewhat agree with those who suggest you look at placement and room issues. This could be a problem, but as you describe the problem as something which seems quite severe, I am tending to look elsewhere. I agree with making sure that the speakers are not pointing at you, but at (imaginary) persons sitting on either side of you. As reported earlier, if the toe-in of the speakers is not correct, this is one way in which you can get the results which you are currently experiencing.