Need some ideas on control room design

This room is on the second floor of my house. Which used to be my bedroom. I picked it because I thought the room has good dimensions. Here is my plan. I want to make the front real absorbant for all freq. and the back I want to construct some polys to have bass absorbers and diffusion. But the more I read threw this forum the more I see that for smaller rooms its best to absorb than diffuse. Am I understanding that correctly? Any help would be great. Joel Ocampo

Hi Joel - welcome to the forum - could you please update your location in your profile - It helps if we know where you are. ;) 18' x 20' is not exactly a small room in my book. If you put your speakers on the front wall and sit say 9 feet back the sound will take 9msec to reach you (sound travels at approx 1ft/msec.) It will then continue past you, reflect off the rear wall and come back to you a further 18msec later. Anything greater than 18msec is OK - shorter delays will confuse the stereo imaging because your ear thinks it's still coming from the front. If you were to sit 12 feet back from the speakers the rear delay would only be 12msec - too short! So in fact your room is big enough to have diffusion if you lay it out correctly. Hope this helps cheers john

Is polys a good way to go then?