Well, actually it scatters down to 350Hz. True diffusion is more traditional for a 7 root diffuser of it's depth - about 500Hz to around 3500Hz. Scattering down to 350Hz and up to around 7kHz. Those are the limits where it starts to act like a flat wall or sound starts just passing through it on the bottom end.
You can certainly use them horizontally in mirror imaged pairs if that works better in your situaion.
There is a big brother to it that's not on the site yet that's 12" thick and has the equivalent of a Monster panel behind it to absorb what passes through on the bottom end.
Bryan