A Quick Soffit Question

I am in the process of building my soffits and just wanted to clarify a couple of points. 1 Does the shelf go right to the back of the box or is there a slight gap? I am using the design John gave to moshwitz. please see the attached picture( I extracted it from the sketchup of moshwitz studio I hope this was ok) 2. I planed to put the shelf 94cm from the floor (the room is 240cm) which would make the speaker about 104cm from the floor is this ok? Any comments are greatly appreciated Cheers Alan

its close to 43% of the ceiling height so this is a reasonable height.

Thanks gullfo. Just another quick question if anyone can help. I am using passive speakers so am i right in thinking i don't need an air gap within the unit? cheers alan

[quote]I am using passive speakers so am i right in thinking i don't need an air gap within the unit? /quote] Yes, you're right - as I understand it anyway :) Gareth

--- or if the speaker is ported on the back or some day you might get active monitors, etc... there's no downside to adding it.