Adding Tone Controls?

You might be a good candidate to try a decent power conditioner on your source gear and/or pre-amp as a first step. Probably can't hurt and only help.

I am not familiar with your digital source gear but assuming that is solid IC changes for a tweak might also help. Try DNM Reson for great top to bottom balance with top notch coherency especially through the upper mids. Or even inexpensive used networked MIT ICs like the Terminator series for a softer sound with more weight in the low end.

Also the no cost toe in/out idea mentioned above is always a worthwhile thing to try before changing anything.

I certainly appreciate all the comments, but I must not have communicated the issue properly, based on some of the responses. Room correction electronics such as the recommended Antimode Dual Core 2.0, power cords, interconnect cables, or power conditioners would seem to impose their changes to the system all the time, for all recordings. I'm not opposed to general improvements, but good recordings already sound fabulous on my system as is.

What I was looking for were recommendations on tweaking the sound ONLY on those recordings that suffer from the misguided hand of the recording engineer.

An equalizer of some sort that can be switched in or out as needed seems the best recommendation I've heard so far. Granted, use of such a device will reduce transparency, and modifies the sound from what the engineer (or the artist) created. Unfortunately that might have to be the price to pay to make the material listenable (to me at least)'

Bama,

HArd to say without hearing, but my gut tells me that there may still some system level tweaking along the lines folks have suggested possible to get the best general performance possible out of you setup.

If it were me, I would exhaust all the possibilities towards that end first to be in the best general position possible before looking to tweak specific recordings or recording types. You could find the need is gone at that point or perhaps greatly reduced at a minimum.

IF there are a lot of recordings of any genre that do not sound good or right, that is usually an indicator that something is still not right in general.

However, the sound of recordings varies widely. If you goal is to merely make them more uniform tweaking the whole system to best effect is not the solution. A flexible or even programmable sound processor of some sort is needed, though I think the extent to which any lesser recording can be made to sound like the best recordings is inherently limited.

Room correction electronics such as the recommended Antimode Dual Core 2.0 ... would seem to impose their changes to the system all the time, for all recordings .... An equalizer of some sort that can be switched in or out as needed seems the best recommendation I've heard so far.

See my post above, dated 11-23-12. As I understand it the DSPeaker Antimode Dual Core 2.0 can be used purely as a parametric equalizer, albeit a very sophisticated one that operates in the digital domain internally (while providing both analog and digital interfaces), and I see no reason that it couldn't be installed in your system such that it can be completely removed from the signal path, when desired, at the flick of a switch.

Regards,
-- Al