Before you start moving your speakers to the back wall or buying wall treatments, have you played with moving the speakers further out into the room and or moving your listening position closer to the speakers, say 7 ft? You might try adjusting the toe-in to help minimize side wall reflections, even if you have to have the speaker axis' cross in front of you. You might also consider putting some heavy drapes on the bay windows which you can draw closed when you listen to music. And you already have observed the problems with all of the windows on the side wall. Again some draps which you can use when listening can be all you need to quiet down reflections. BTW, do you have rugs/carpets on the floor between your listening position and the speakers to reduce floor reflections?
Wall/room 'treatments' are specific solutions for specific problems. You've got to figure out the problem before you start buying solutions. Or you'll go broke and be frustrated unless you are very lucky.
Test CD's/LP's can be very useful, especially in the bass if you have a SPL meter. It will help you to identify not only the best place for speaker placement but room placement as well. Upper frequencies would also be measurable but might not be as helpful in identifying proper solutions. IMHO.
BTW, the excessive bass problem might be a product of the speakers proximity to the back wall (too close) and or corners.
Oh, while I'm thinking about it - opposite wall surfaces, i.e. live v dead, can be a good set up, if done properly, because while it doesn't kill first reflections, it will tame 2d reflections and things like echo slap/reverberations.
Hope that helps a bit.
Wall/room 'treatments' are specific solutions for specific problems. You've got to figure out the problem before you start buying solutions. Or you'll go broke and be frustrated unless you are very lucky.
Test CD's/LP's can be very useful, especially in the bass if you have a SPL meter. It will help you to identify not only the best place for speaker placement but room placement as well. Upper frequencies would also be measurable but might not be as helpful in identifying proper solutions. IMHO.
BTW, the excessive bass problem might be a product of the speakers proximity to the back wall (too close) and or corners.
Oh, while I'm thinking about it - opposite wall surfaces, i.e. live v dead, can be a good set up, if done properly, because while it doesn't kill first reflections, it will tame 2d reflections and things like echo slap/reverberations.
Hope that helps a bit.