What commerical audio system tweaks provide sound quality improvement??

Ok, so let me ask the obvious stupid question. I know that resistance in electricity is big. The less resistance the better more usable current. I have 14g ordinary radio shack speaker wire run to all my klipsch surrounds and rear surrounds and my mirage os3 fs towers and mirage os center. Would I REALLY notice a difference upgrading those cables? 14g shouldn't have too much resistance coming from an Emotiva xpa3 and xpa5 right? But i do have custom badass interconnects 

Well badass for me. They're a 12g belden wire with silver connectors 

I have tried numerous tweaks in the many, many years that I have been into this hobby (obsession?).  Some have, IMHO, had little effect on sonics (like a green felt pen to coat the rim of CDs) while other have led to much more benefit.  My most recent tweaks were replacing stock fuses in my system with Synergistic Research Black fuses.  Amazing and unanticipated improvement in soundstage and detail.  Tube rolling can also be an effective tweak.  Also, consider replacing cables (interconnect, speaker, and power).  I have also fooled around with footers (not a fetish) but have heard only minimal improvements in sonics.  Try to audition tweaks before committing to purchasing.  Enjoy!

Three additional tweaks are
a) cryo-treating cables and equipment
b) footers from Anvilturntables
c) replacing amp binding posts (or iec ac inlets) with silver or rhodium plated pieces

I learned about cable value by borrowing 4 pairs of increasing expensive Audioquest interconnects from my local audio dealer. I found the quality of the whole sound/presentation improved at each level. Today I have more expensive cables than I could afford to buy in post 2008. I only wish I could afford the Tara Labs Zero, or at least try them in comparison to some really expensive cables. 

Vincent Raptor