Low Cost Accoustic Diffusor and Treatments

I can only comment from my years of trial and error. But here are some ideas in no particular order:
* DIY is always less expensive (save for your time) and allows you to engineer it just right for your room and it's unique constraints.
* polyfusers (hemi cylindrical) stained in a rich color can look like architectural columns and will diffuse mods and high frequencies while absorbing low frequencies. These can e made by bending thin plywood or as I did (see my system for pics) use a Sonotube and cut it in half lengthwise to create a 180 degree arc, sand off the wax and then glue on a wooden veneer and stain.
* of course other geometrical shapes work too
* put wooden boards on piano hinges attached to a wall that allow you to open or close them to any angle so as to reflect reflections up and away or out to the side walls (see my system pic again).
* my artistic oriented friends think a Skyline diffuser looks like a really cool art project yet diffuses in two dimensions.

I can send you instructions on any of these DIY projects if you want. Hope this gets the creative juices flowing . . .

I use wood and metal Wind Chimes they work very well with other acoustic diffusor treatment. Click on my system link.

I like chimes, too. I also like those little Feng Shui fountains and Feng Shui one inch diameter clear crystal ball suspended from the ceiling by its red string.

Nice Geoffkait. Do tell us whether those Feng Shui fountains and crystal balls suspended by red string are absorbers or diffusors....

Kiwi wrote,

"Nice Geoffkait. Do tell us whether those Feng Shui fountains and crystal balls suspended by red string are absorbers or diffusors...."

Neither.

Is that a satisfactory answer?