[ctviggen]

Looking at some old graphs put out by my ETF program, I can tell that my room lacks diffusion.  This will get worse, as I currently have my office in my HT room.  Once my office moves out, the rear of my HT will be like an echo chamber.  I plan on adding some absorption, but I also want to add diffusion in the back, along the side, and on the ceiling.  

RPG seems to make some excellent diffusion products:

http://www.rpginc.com/products/index.htm

For instance, the Skyline looks a great product for the ceiling.  However, these are $300 per piece -- for foam!  That's obscene, especially when I'd need 10 or so of them.  The omnifusor also looks good for the ceiling, but I think it's also quite expensive (I cannot find prices for it, though).

Is there a company that produces diffusive elements such as these yet at half the price?

[woodsyi]

Bob,

Would these be any good?  

http://www.sweetwater.com/store/detail/MetroDiff

I may get some of this and use them as ceiling tiles.

[ScottMayo]

Is there a company that produces diffusive elements such as these yet at half the price?

If you need pure diffusion and not too much absorption, this is one of the easier things to build at home. Materials run under $100, and that includes cloth to cover the surface. You can also do tricks that add absortion. PM me.