How large does an aperture have to be for sound to pass through it?

[thadman]

I'm just curious, how wide (relative to wavelength) must an aperture be for 100% (or near 100%) of a sound wave to pass through it? F. Alton Everest specifically stated in the Master Handbook of Acoustics that if 13% of a thick steel wall was free (ie holes/slits) then 97% of the energy would pass through...Is this wavelength specific or universal to all wavelengths relative to the aperture?

Think of it like this

____ ____ ____ (3 4" obstacles with 2 .5" apertures, a 1700hz wave (~8") would easily diffuse around the 4" obstacle, but is the opening large enough for the 1700hz wave to pass through?)

for reference to wavelengths, the sound waves wavelength must exceed the fundamental baffle width (wavelength>baffle width) before the 2pi to 4pi transition can occur

[thadman]

C'mon you acoustic gurus, I know one of you is just itching to share your knowledge with the community :B

I'm interested in the effects on the front of the array of obstacles (ie how wide for no reflection of energy to occur), not the rear side.

[wildfire99]

Perhaps it would be better to approach it from the point of view of why you need to know? Is this a science experiment or are you trying to hide speakers behind a wall or something? Or do you have an open room and want to listen loud without bugging the neighbor?