What has been the most cost effective upgrade or change to your listening environment (acoustical treatments, speakers, specific component, etc.)? Please describe the change as you experienced it. Speakers, I went from one surround set-up and a 2-speaker set-up to two surround set-ups. The speakers I purchased were all upgrades, and the improvement in sound quality is very apparant.
What I had - System 1 - Receiver - Onkyo DR90; Mains - Infinity RS3s; Center - AR 18; Surrounds - Polk R10s
System 2 - Very old Marantz, 2-channel receiver (Sounded great, but one channel is on the fritz) Speakers - Optimus, Minimus 7s
What I have - System 1 - Receiver - Pioneer 912k; mains - Infinity RS3s; Center - AR 18; Surrounds - BIC Venturi 52s;
System 2 - Receiver; Onkyo DR90; Mains - BA HD 5s; Center - AR 18; Surrounds, Polk R10s.
A hodgepodge, but they both sound pretty good, especially system 1.