Best DIY tweak?

A new chair in the listening position was a good one for me. It sets about 3 inches lower than my original chair. The sound stage depth increased and it's more comfortable.

Just what is your definition of "dramatic?"

That is an excellent question 2chnlben. Whenever I read someone made a minor tweak such as cable swap, green ink, magic pebbles or whatever and noticed a "dramatic" change I'm skeptical. Although I have heard both sonic improvements and degradations with various tweaks, they have never been dramatic or changed the overall flavor of my system.

Cheapest tweak? How about a couple of cotton swabs to clean your ears out. Only a few pennies.

Although I didn't discover it speaker placement has the greatest impact with my system and room!

Oh yeah, another DIY tweak would be cleaning all the connections between cables with alcohol to remove any oxidation that might get in the way of the signal path. Worth doing at least once or twice a year. Try it, and you will be amazed.

Replace steel speaker driver screws with solid brass screws; dramatic results!

That's not a tweak, man.......that's a mod. Where's your entrepreneurial spirit?