Hi Tension255,
Its easy to say to switch the speakers to a less 'bright' model. But then you need to have an appropriate amplifier to match those speakers, and so the cycle begins. So I understand that you are looking to tame a system that is brighter through the use of cables.
Have you looked into adding some tweaks into your system? Some tweaks such as vibration control will help tighten up your bass, which in turn can bring out more of the midrange frequencies. Power cables can do this, as can upgraded speaker wires and interconnects. Power conditioning as well. I like tweaks, especially the more reasonably priced ones, because they all can add up to an improved overall sound, and you can take them with you when you upgrade.
I recently added some Bybee Technologies Quantum clarifiers to the bass drivers of my Von Schweikert VR1 bookshelf speakers, which definitely improved the bass response and clarity. Better soundstage, and smoother and more air in the higher end. They are 2" square units and you simply attach via magnet to the rear driver magnet. $200 a pair for this tweak, and you can take it with you if/when you upgrade. I have a bigger one on my amplifier as well - an Antique Sound Labs KT88 based integrated.
What kind of speaker stands are you using, and are they weighted down? These can make a difference as well.
I find that if you improve the bass response, you'll have a more balanced sound, because you will be bringing out more of the lower harmonics and transients of the music. Hope this helps.