Quote:
Originally Posted by andrebrito  Adding diffusion to the ceiling is going to make the room less live since the spread out of the reflections is higher and the free path becomes shorter which results in higher reflections order. This is particularly visible in large rooms but also occurs in small ones. |
I agree.
By the term "live", most folks are actually referring to ratio of the direct sound level to the first reflection level.
This also presents additional increased destructive factors in terms of intelligibility, imaging, polar lobing nulls, and issues regarding such factors as micing, etc.
Using diffusion breaks up the reflections and more evenly distributes them both temporally and spatially, which will tend to decrease the perception of 'liveness' by virtue of a more uniform distributed sound field.
Such a modification reduces the destructive anomalies in exchange for a much more uniform soundfield devoid of the gross destructive anomalies as the diffuse reflections are reduced in level relative to the direct signal (re. Henry Precedence Effect).
All of that being said, the use of diffusion in this instance would be superior to the use of absorption that simply reduces the total energy without diffusing the ambient sparse specular reflections. And we are here only suggesting its use for the vertically directed specular reflections via the use of a collimating phase grating/diffusive cloud.
It all depends upon what one desires, but for the purpose of a 'live room' I will trade a room featuring a diffuse sound field for one dominated by reduced acoustic energy and sparse specular reflections any day.
...And I wish CATT and EASE and Ulysses worked as well in small acoustical spaces as they do in large acoustical spaces...If they did, this forum would largely be a moot issue.
