Okay... so I've been researching poly-cylindrical diffusors... Someone check me on this please: From what I understand, diffusion itself does not lessen the energy of frequencies, but instead, actually creates more reflection(s)... but in doing so, it lessens the intensity of these frequencies. The smaller, scattered frequencies will have random phase as a result of their individual and random "throw" around the room, and this can result in a smoother RT decay curve in the room. So first of all, am I correct in the basic understanding of a diffuser's main purpose? --------------------------------------------------- Here are some details about the room, should they be required: Room Materials: older type sheet rock on the walls and ceiling. The house was built in the 1940's. There is insulation in the walls, although not much. It appears to me to be the cheap blown-in style of material. Between the ceiling and the floor upstairs, there is OC R19. (I know this because I put it in myself). The floor is hard wood - oak, stained and sealed. There is one door, pretty sure it's pine, stained and sealed. There are two windows - L 52" x W 32"; both are newer (within the last 4 years) double pane, energy efficient. Room dimensions: 14' 6" L x 12' 3" W x 7' 11" H Splay: The walls on both the L and W dimensions vary from end to end by up to two inches. The floor and the ceiling differ in height by 2 inches... but not on an end to end basis. The difference is in the middle of the room where either the floor has settled or the ceiling has sagged. So the room is not exactly square. ------------------------------------------------------ The most obvious question is, do I need diffusion of any type at all? If the answer to this is yes, or probably, then I'll continue... Before I continue with my questions, I should tell you that I have been doing a lot of research on my own... I'm not trying to be lazy here. I have looked on the web to find the answers to these questions, but I've either not been able to find the answers, or I have run into contradictory information. It's also very possile that I'm not asking the correct questions... That being said... If diffusion would be beneficial in my situation... 1. would I be better off using a poly-cylindrical form of diffusion as opposed to the "skyline" type that I have already built? 2. if I can - or should - consider using poly diffusion in my room, does anyone know where I could find the formula needed to calculate the size and/or amount of the poly cylindrical diffusion that I need... width, depth, curve, etc. 3. can I make a diffuser of this type that serves 2 separate purposes - those being diffusion and absorption? For example, along the wall behind me, where the wall meets the ceiling, could I run a 12' length of poly diffusion along this section, but in doing so, also add absorption material inside the diffuser? If this is possible - because I'm dealing with a half cylinder shape - I would think that something like Roxul would be better to use, than trying to fit and meld rigid glass with the shape... (and also allowing myself enough room for a 2" air gap between the insulation and the wall). Would any of this serve a purpose that would be worthwhile? Or am I into a more esoteric type of treatment which leans towards diminishing return? Any info would be greatly appreciated d/ .