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Monday, March 21, 2022

Masonry acoustics, part deux

 I recently finished the second coat of paint on the living room of a building I'm currently completing. Since it is clean and empty, I thought this might be a good time to briefly discuss the room's acoustics.

My dear father left me a pair of Klipschorn speakers, something of a 'classic' pair of loudspeakers, designed and made by Paul Klipsch.  These are a pair of vintage speakers, renowned for their efficiency and warm sound.



Knowing that I wanted to place these speakers in this room, I consulted the Klipsch website to find out what the optimal design and proportions of the room should be. "Klipschorn speakers typically perform best when positioned in the corners on the long wall of a rectangular room. If the room is very narrow and long with corners farther apart than 18 to 20 feet, the stereo image may not be optimal. A room with a length to width ratio of 1.00 to .618 is preferred."  The same ratio is applied to the height of the wall, so that the ratio of the width of the room to its height is 1.00 to .618. These ratios resulted in the room having the dimensions of 30 ft. 8 in. long, by 19 ft. wide, by 11 ft. 8 in. tall.  The arched ceiling goes to a top center height of 16 ft.

The ratio of 1.00 to .618 may sound familiar to any mathematically inclined people.  This is the ratio provided by the Fibonacci sequence.  These ratios are ideally reflected in al three axes: x,y and z.  Thus the proportions of the room are those of a 'golden cube.'  These same ratios are found in the Greek Parthenon.  It is both visually appealing and acoustically beneficial.  Some say that these ratios help prevent constructive or destructive interference of certain frequencies; this idea seems to be disputed by others.



The only other suggestion offered by Klipsch is to include an arched ceiling, for more resonance and a fuller sound.  This room has an arched roof, it's the focus of my work.

The stereo sounds great, it really rocks out: whether it's Beethoven or Jimi Hendrix.