Thanks mate, I know there's a few folks on here who i can trust, venturing onto a new forum I suspect I'll get a load of noise. I'm going to run a few trials, bit I'm pretty confident that the above picture is more a case of the manufacturer wanting to sell what they want to sell as opposed to offering reliable advice. I assumed that because they'd placed pairs of absorbers/diffusers at reflection points for the monitors, that there might be something significant that I was missing - who knows, even a new magic bullet for acoustic treatment - but my gut feel is that in a room the size of that in the diagram you wouldn't put the diffusers where they've put them.