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
Quick interrupt! If I’m not mistaken the tiny little bowls work for headphones, too. Bigger sound, more energy, more dynamics, subjectively louder, much better and more powerful bass. What the ding dong?! I just installed twenty copper tube caps, half were 1/2" diameter, the rest 1". Almost all were placed in upper corners of the main room and other rooms throughout the place, you know, just to see what would happen. Whoa!!

addendum: I use glue dots to stick the tiny bowls directly to the wall or ceiling surface. One foot out from the actual corner. One one or more of the three surfaces per corner. Use only Super Strength/ Ultra Thin Glue Dots brand.
geoffkait,

Since you seem to have experience with horizontal storage can you be a bit more specific other than your reference to mumbling?

jkbtn,

I use copper beading cones inserted in copper caps. I have no idea if brass will work as well. Never used brass. Give it a go and let us know how this works out. According to Franck Tchang, different metals give different results. Hence his use of various metals in his resonators. Although you may get good results with brass, of course you would need to A/B test in order to ascertain the difference between brass and other metals.


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.