Sloping ceiling: Calculating angle?

I'm looking at having a sloping ceiling in the new room I'm building at the end of my garden, starting low at the wall the monitors are on and sloping upwards towards the middle where the mix position will be. I originally happened on this design because I wanted a pitched roof for external aesthetic reasons. Then I read that it could be good for acoustics too, helping to deflect early reflections past the mix position. So I thought - all the better. At the moment I'm just planning on a simple symmetrical slope rising to the half-way point in the room, but this is open to revision. (My origianal plan, which some may have seen in another thread, had the pitch about 2/3 of the way along). The heights have been determined by a combination of practical and aesthetic factors: a practical minimum for the height at the wall; an aesthetic maximum for the middle as I don't want to overpower the garden etc... Can anyone enlighten me to any acoustical factors I should take into account that might affect these dimensions? How does one calculate the early reflection paths from the monitors? (I'm looking at mounting nearfields as close as possible to the wall, and sitting about 2 metres away). If it would be advantageous to alter the angle of the pitch either way I can probably do it - it's just I've got no idea what's best. Here's the current plan. Outer wall is 100mm dense concrete block, inner wall two layers of plasterboard (drywall) on timber frame with rockwool in the gaps. Air space between the two probably about 150 - 170 mm (including rockwool). Dimensions are in metres.

The sloped ceiling really helps stops floor to ceiling standing waves so if you can get it up to 12 degrees it's the best way to go. It should keep angling to past the listening position. cheers john

Thanks a lot John. Do you mean as close as possible to exactly 12 degrees, or at least 12 degrees (ie, more would be better)? The sloping ceiling WILL also help with early reflection paths, won't it? Or have I got that wrong?

John, Could someone use a type of cloud array to get that 12 degree sloping effect? Maybe put rockwool on the backside of the cloud to knock down reflections between the wall and the cloud? Aaron

At least 12 degrees.:) yes - you could use a cloud like you desicrbed Aaron.

What's a cloud array?

I've worked out that if I keep the inner wall height at 2.40 metres, and extend the inner room height at the peak just from 2.85 up to 2.90 metres, that will give me the 12 degree slope I need. That's probably gonna be as tall as I want to go, so if I want even more angle I'll need to take the wall height down a peg. That however has implications for fitting the door in, as 30cm of the height is underground, but the door will be at ground level (with a couple of steps down from it inside the room). Looks like I'll be OK though. Thanks again John.

"What's a cloud array?" Check out the treatment above the mix position 8)