The simple answer is as follows. Half, quart or third round devices or objects individually just scatter sound. A single barrel diffuser or tube radiator as I often call them just create a very uneven distribution of sound. As single units, it gives about the same amount of performance as placing a flat object of the same size and placing at a 15 to 35 degree angle on a wall.
When using barrel diffusers in various sizes and/or in spacing varying from 0 to 30 inches and apply them to all of the walls in a confined space, you are creating a diffusive field. You’re turning the church walls into a phase coherent sound field – like churches of yester year built between the 1400’s to 1700’s. When barrel tubes are used as a system you can program them to only manage the acoustical problems you want to get rid of and at the same time create a more desirable sound field like real reverberation that is musical and supportive to congregational singing.
Barrel tubes spaced too far apart just scatter the sound and reduces some bass but does nothing much else. Instead, you can program the diffusers to manage standing waves, bass buildup, notch a frequency or two and equalize a room. You can also program them to lower stage noise, manage monitor spill into the audience and improve congregational singing. They can also be programs to make the sound system perform better.
The software to program barrel diffusers is still in development. In the meantime, a test room, and a data base of real world testing is the best way to predict the final outcomes. Try and program a digital EQ to cut 350 hertz 40dB. It can be done but it sounds awful. When you program tube radiators to cut 40dB, it sounds sweet.
Joseph De Buglio
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