I used to have the old Sony receiver's Front A Left and Right outputs hooked up to the Front Left and Right speakers.
The Pioneer is the same in that respect.
And, I used to have the Front B Left and Right outputs going to the sub's Speaker Level Input Left and Right.
OK let's reference your Polk PSW 10 OP Manual to go further...http://www.polkaudio.com/downloads/m..._12_Manual.pdf
The Polk Manual shows setting up your Sub by going from the Receivers Sub Outs and then into the "Line In" on the Polk Sub.
However in the Polk PSW10 OP Manual there is a Sub Note that states:
NOTE: The PSW10 subwoofer does not have an LFE input. Instead, use either the L or R Line input (another hookup option is to use a Y-split cable and connect both L and R Line inputs).
After you make this Sub Out connection, turn the "Low Pass" filter fully clockwise. This will in effect create an LFE input.
How can I tell the receiver I have a standard 5.1 speaker system (no Front Highs/Wides, no Surround Left or Right, no second zones, no bi-amping - only Center, Front Left and Right, Rear Left and Right, and Sub) and that I want to use the Speaker B High/Wide outputs just like I did my old Speaker B outputs - as a full signal, Large output?
Look on page 12 in the VSX 1121 OP Manual, I am thinking of a couple of options.
1) Choose "C" / Speaker "B" configuration and then in the Pre-Outs section, I would go from FH/FW Pre-Outs RCA L & R to your Sub's RCA Line In L & R Inputs.
Because this is just giving the Sub a Stereo feed it might be OK
2) I am also leaning towards just the default setting of "A" SB/FH and then use the Pre-Outs for the Front Left & Right Speakers going to the Polk PSW10's Line in L & R
Even though "A" is for 7.2 and "Front High" you don't need to have all of the speakers connected for a 5.2.
In MCACC it will find which speakers are connected and adjust accordingly, I use this setting with my Elite VSX 53 and I have a 5.1 Surround System.
Just remember that in a 5.1 Surround use Surround Left & Right and not Surround Back Left & Right!
See this on Page 14 of the OP Manual for the VSX 1121.
From looking at the Polk PSW10 OP Manual I guess that I would run the MCACC with Speakers set to "Large" and on the Polk PSW10 turn the "Low Pass" filter fully clockwise.
This will in effect create an LFE input.
I am wondering what the Pioneer will do to the "B" Speakers Pre-Outs when you run the MCACC. and the B speakers is the Polk?
When using the Pre Outs for fronts that also have front speakers it will run rhe MCACC as normal and then the Sub is just getting the A Speakers. L & R
Just start off with the Default setting of SB/FH Speakers "Large" and after the MCACC is complete THEN connect the Sub's RCA Line In's from the Pioneer's Front L & R.
If you do any MCACC with speakers set to "Small" then all of the Sub's Frequency's will be cut out and that would not be good for sending the Pre-Out to the Sub!
Maybe some others will chime in here with some further thoughts or if they have a setup like this.