True Blue:
Has any one made these and to what success. Thinking of making some myself so any hints tips or suppliers of bits etc welcomed.
Never used any but it's worth getting a list of possible absorptive material. I would look at Rokwool RWA acoustic panel's. I've used this in a home environment and it does the job. Easy to use and cut, also cheap.
I have a pack in the garage you can have for free if you can collect from J5 M40..
True Blue:
How exactly do you determine where the things go as well??
Use a mirror around the room. Anywhere you see the speaker a panel may be needed.
Out of interest what problem's are you getting?