Hi, Currently I have below setup. 5.1 (with Bi-amp) Receiver : Yamaha RX-V677 Front L&R : JBL ES80 (Connected as Bi-Amp) Front Center: Polk CS2 Series II Surround: Polk Monitor 40 Sub Woofer: Klipsch R-12SW So far sound is OK but not very impressive hence I am trying to see if any upgrade here will help. Also note that I have different brands of speakers for front L/R/C , not sure if its a problem. as of now I am kind of happy with below components. - JBL ES80 - Klipsch R-12SW So trying to figure out what would be best value upgrade to make sound great. I am looking at SONY STR-DN1080 to replace the receiver and see if Center speaker can be replaced with any other JBL brand speaker? What you guys think? is these upgrade would help or any other suggestion?