Know of a "Dirt Cheap" tweak?


I am looking for tweaks to improve the overall sound quality of my audio system. I recently purchased some TPC contact cleaner and it made a believer out of me. I noticed a signicant improvement, as if a veil was lifted my system sounded more clear and transparent. Bass got tighter too. Do you know of any cheap tweaks that have made a SIGNIFICANT improvement to the sound quality of your Hifi system...let us know... :-) Comments welcomed!
kasboot
Mass. Adding weight to woofer enclosures may help definition. Bricks on top, whatever you have handy. :)

Especially good for 2 and 2.5 ways with the woofers closer to the tweeter than the floor.
Drill holes in refrigerator for cables and place all electonics on racks inside. Support refrigerator with springs to isolate the while kit and kaboodle.

Take some Blue Tac or some similar putty and make a small ball with it and put it under the edges of various circuit boards in our electronic equipment.. This sort of adds vibration control and damping and can be easily removed.