Originally Posted by megabyzus
The receiver's an Onkyo TX-NR616. The two subwoofers are POLK PSWi225 wireless subwoofer. I see the subwoofer has two types of inpouts: 1. Single Input (with 'LFE' printed below it) and An 2. L/R RCA input pair.
This is where my question comes from: Why the two types of inputs on the subwoofers and why can't I connect the L/R's to my 'regular' speaker outs on the back of my AVR?
Your subs' LFE inputs likely bypass their on-board crossovers and are designed to use the low-passed feed from the AVR's bass management along with the band-limited LFE. The L/R RCA inputs likely invoke the subs' on-board crossovers. Read your sub's manual or contact Polk's support for confirmation of the correct course. I see you've now moved to selecting the "regular speaker outs", I don't know if that is referring to the front channels. If it is, then you could set the front speakers to LARGE with LFE and send their pre-outs to your subs. But, your subs will need a very steep low-pass filter (and/or a very low filter frequency) to keep the subs from muddying-up dialog. This is a very unusual connection scheme that isn't often seen (and is full of pitfalls), so it's difficult to recommend.
The pre-outs for the surround channels will not carry LFE (a tremendous loss for movies) and the surround channels are likely high-pass filtered, so you've now removed almost all the bass from the subwoofer feed.
This connection scheme is so wobbly that it boggles me.
I'm rather surprised to see your resistance to using the subwoofer outputs of your AVR.
The outputs carry the label "SUBWOOFER" for a reason, they are designed to be used with subwoofers.