Most effective Room Treatment for slap echo, etc

Thanks to all members for their suggestions and recommendations. I appreciate you taking the time to respond. Hopefully, I will be able to eliminate the acoustic problems mentioned above by your input. Jim

It looks like this thread has ran out of gas. Nevertheless,I checked with Gikacoustics and Ats acoustics. Gik provided more informed advice and a AT plan for my room, but the price with shipping is too expensive . Though, I did move the speakers to the long axis and moved my couch out about 30 inches from the back wall as recommended by GIK---the sound did inprove in "some" areas. However, I noticed something today that might have an obvious answer. On louder passages of music, there seems to be less clarity, and also more noise, that is, congestion of the sound. Someone may advise: "Turn it down you are playing it too loud"....OR, is the amp clipping, or is my amp Creek SE5350 Classic coming up short in terms of dynamics?? One more point, it also seems that the room is amplifying the sound or making it louder... Need some input. Thanks again Jim

Kevinzoe, I did use some of step #1 by closing the slat blinds behind the speakers in the relocated long axis location. That, in combination with the one large bookcase have eliminated or lessened the slap echo, at least in the section of the room----there is more clarity at higher volume. The RPG diffusers have not been investigated because I am sorting out other other recommedations. I did make one change. On Thursaday, I got an earful of two CD's with the old speaker wire. On Friday, I was able to install the AZ Hologram II speaker cable which made a moderate to big difference---sound is warmer with a little less bite in the highs, bass sounds a tad slower. I could say more, but must run. If you have the time, check out Misc. formum. I launched another thread: "Can room acoustics amplify the sound from speakers?" I did so because of a phememnon I discovered last week. The responses have been interesting to say the least.

Kevinzoe, I did use some of step #1 and #2 by closing the slat blinds behind the speakers in the relocated long axis position. That, in combination with the one large bookcase have eliminated or lessened the slap echo, at least in the section of the room----there is more clarity at higher volume. The RPG diffusers have not been investigated because I am sorting out other other recommedations. I did make one change. On Thursaday, I got an earful of two CD's with the old speaker wire. On Friday, I was able to install the AZ Hologram II speaker cable which made a moderate to big difference---sound is warmer with a little less bite in the highs, bass sounds a tad slower. I could say more, but must run. If you have the time, check out Misc. formum. I launched another thread: "Can room acoustics amplify the sound from speakers?" I did so because of a phememnon I discovered last week. The responses have been interesting to say the least.