I have come to think that the problems need to be adressed at the root. Speakers and their interaction with the room are responsible for 90% of sound quality:
1 it is an illusion to think that it will ever be possoble to have really good sound in that room. It is too small, and because it is square, the room modes will also be bunched together. All that is possible is casual listening with a pair of mini monitors (you could use your old speakers for that, with a cheap Sony STR 130 if you still want some sound in that room).
2 Since speakers are so important, and because they are also by far the most expensive component, you have too many of them and they are not as good as they should. Why not opt for a 2 channel HT system? That is what I did: you give up some surround effects, but you gain a lot of sound quality. Since you seem to be in a position that you can return a lot of your gear (all the Polk stuff, including the Polk Sub (?), the Sony, and perhaps also the LG disc player?), do so. Move over to the mid size room, and use whatever budget you have to buy some really good speakers (Harbeth M30.1?) and some affordable electronics (Harbeths do not need fancy electronics or cables - sell those too if they are worth any money). How much budget would this create? Electronics: for example an Oppo 205 disc player and pre amp (if your LG does not have the right inputs and outputs and volume control), plus a beefy Emotiva or pro audio power amp.
1 it is an illusion to think that it will ever be possoble to have really good sound in that room. It is too small, and because it is square, the room modes will also be bunched together. All that is possible is casual listening with a pair of mini monitors (you could use your old speakers for that, with a cheap Sony STR 130 if you still want some sound in that room).
2 Since speakers are so important, and because they are also by far the most expensive component, you have too many of them and they are not as good as they should. Why not opt for a 2 channel HT system? That is what I did: you give up some surround effects, but you gain a lot of sound quality. Since you seem to be in a position that you can return a lot of your gear (all the Polk stuff, including the Polk Sub (?), the Sony, and perhaps also the LG disc player?), do so. Move over to the mid size room, and use whatever budget you have to buy some really good speakers (Harbeth M30.1?) and some affordable electronics (Harbeths do not need fancy electronics or cables - sell those too if they are worth any money). How much budget would this create? Electronics: for example an Oppo 205 disc player and pre amp (if your LG does not have the right inputs and outputs and volume control), plus a beefy Emotiva or pro audio power amp.