What a difference curtains make...WOW

I am now taking time to listen everyday now. I believe I finally have good speaker placement as well. I actually think my system sounds better now than it did before with a subwoofer. I read somewhere (maybe TAS or Stereophile) that the weakest link in 99% of home audio systems is the listening environment.

Now try putting some GIK corner traps (or 244 panels) in the corners of your room to absorb the boomy low end and report back.

Any suggestions on curtain material?

Be careful not to overdo room treatments, as they can kill the life out of your speakers. Treating the room is a necessity, but you can easily hear the point at which the sound is just dead.

It also depends on your speaker design. Some designs doesn't require heavy room treatments but more detrimental to the speaker performance when used, while others require extensive room treatments and environment placement. It just depends on the design and type of equipment used. curtains or heavy drapes can absorb too much sound waves on some systems which makes the system dull, while others helps tame brightness or over reflection. Some sound engineers used to warn against placing loudspeaker near draped locations in past findings. If your loudspeaker requires hard floors and solid walls to perform it's optimum, treating the room with drapes or curtains may not be ideal. Some bipolar or dipolar designs are heavily affected by such set up.