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
Sabai, the sound will be more transparent and more coherent compared to the case when they're stored horizontally. 
sabai,

Could you post some photos that we can look at? I'd like to know how those copper beading cones are inserted in copper caps.
I have found that applying  black permanent marker ink to the outer edge of a CD improves the overall sonic quality (better than the blue-green Stoplight).
 

jpmeurer2
I have found that applying black permanent marker ink to the outer edge of a CD improves the overall sonic quality (better than the blue-green Stoplight).

While I have to admit that’s it’s quite counter-intuitive, black is actually not the best choice for the outer edge and should never be used for the label itself. I think this use of the color black on the outer edge might possibly be an excellent example of expectation bias. On the other hand black should always be used for the inner lip of the CD. Green or blue green is the best all around color for the outer edge but there can be exceptions since the color of the CD influences the sound as well. Blue green happens to be the complementary color of red so one suspects it absorbs red scattered light. But wait! The CD laser is 780 nm - which is invisible! Whaaaaa? Then there’s the color purple, which is also an effective color for the outer edge, who knows why? I might as well mention a notable exception - the Mercury Living Presence classical CDs released in the 90s with those iconic black and white labels. Those CDs should get red ink on the outer edge.