Cables to settle brightness

Don't worry about your power cables.  But get rid of EVERY INCH of silver conductor in the signal path.

That old misconception " silver is bright " might not apply since op haven't mentioned having any kind of silver/ silver over copper cable in his/her system. 

I do share the opinion that using cable as equaliser is a bad idea, changing equipment to find synergy might be more inconvenient but mostly more rewarding in the long run! 

Many recordings have a hot top end. What you are hearing is likely an accurate rendering of the recording. Rock music is particularly bad in this regard! Turn that Marshall stack up to 11!

Many recordings have a hot top end. What you are hearing is likely an accurate rendering of the recording.

This may be true, and I agree that taking the recordings into account is very important when assessing a problem. I moved into a new home recently, and am in the process of taming some bloat from the bass produced by my rear ported speakers. During the process, I have noticed that in well recorded music, the bloat is very subtle at most. But in others, typically more popular soul and funk, etc., the bass was clearly boosted, and the problem is therefore much more pronounced.