polk4liffe

Polk psw505 port noise! So I have a decent theater room all setup. Room size is 16 x 25. I am currently running Polk monitor 60s for my fronts , Polk monitor cs2 as my center , Polk monitor 40s for front height , Polk monitor 40s for rears , and two Polk psw505 subs all powerd by a Denon avr s920w. I love it . But my issue is I watched mad Max fury road last night which was amazing but there were times where my subs port noise made me feel like I had cheap subs. Was curious how i can fix this without loosing performance. My subs are roughly 2 feet from the back wall. Which made a difference in performance but I need that noise to stop. Any ideas? Should I set fronts to large and adjust the crossover differently so I can turn the volume down a tad on the sub? My subs are currently set up with the following. Crossover set to 120 because of lfe (lfe+main on amp) volume is set right in the middle.