At a computer music conference in Sweden in 2002 I heard the Gothenburg Symphony play a piece for electronic music and orchestra. There were huge speakers suspended above the orchestra to diffuse the electronically produced sound. The piece illustrated a typical problem with electroacoustic music. Acoustic instruments are a point source for their own sounds. The sounds raidate outward in all directions and interact acoustically with the interior space. By contrast, sounds diffused through loudspeakers are driven directly at the audience from the outside in. In electroacoustic music, whether there is one solo instrument or a whole orchestra paired with electronically produced sounds, the effects are so different acoustically and in terms of audience reception, that ne'er the twain shall meet.
One way this problem is addressed is to mic the acoustic instrument(s) (with the Gothenburg Symphony it would have been necessary to mic the whole orchestra). This typically solves the problem of mixing the two sources of sound, but at the expense of source indentification and spatial presence for the acoustic instrument(s). Diffusing the sounds of musical performance through loudspeakers dissociates the sound from the actions of musicians onstage. That is why musicians in a rock concert typically perform outlandish theatrics while they play. It correlates their presence onstage with the massive hundred-decibel sound experienced by the audience. Without a clear correlation between the human actions of musicians onstage and the sounds heard, one may as well sit at home and listen to a recording.
In Croatia in 2006 I saw a presentation at an acoustics conference by a physicist from University of Bolgona. He uses a speaker ball to map the acoustics of Itlaian opera houses. The speaker ball emulates the sounds of acoustic instruments and human voices in the space. In 2007 I saw a funny article in The New York Times about someone who made a speaker ball out of two large plastic IKEA bowls and a few cheap speakers. It finally occurred to me that electronic music could be diffused in this way to make it emulate acoustic instruments so it could be better integrated with them. Rather than putting a mic on the acoustic instrument(s) to emulate the diffusion of electronically produced sound, I could try to make the electronically produced sound diffuese in the space more like the acoustic instrument(s). This would also provide an identifiable point source for the electronic music.
I found out other musicians had this same idea, had presented a paper on it in 2000, had a gallery up on the web. that others had done some serious research on it, and that one outfit is selling a commercial product. I chose materials for my own speaker ball, made a sketch... ...and Thanksgiving week of 2007 constructed it:
is a 40 quart polycarbonate salad bowl (that's 10 gallons).
used two of them.
were easy to mark with a fine-point Sharpie...
to drill, and easy to cut with a jigsaw.
put fiberglass insulation batting in each half to dampen sound inside
a bead of adhesive caulk...
the two halves together with screws through the rim...
the body of the enclosure was complete.
applied a spray-on flecked "faux stone" coating and a coat of clear
is the inside of a drum lug for a floor tom with foam rubber weather
stripping applied around the edge.
drum lugs are for legs to hold the unit up off the floor, and also hold
the two halves together more securely.
30 W RMS 4 Ω coaxial car speakers with ready-made crossovers (and a
rated frequency response of 40-22,000 Hz) were wired acording to this schematic diagram and this wiring plan.
stripping was applied to each speaker opening...
wired speaker put in place...
with machine screws and locknuts through the escutcheon plate...
protected with its formed metal screen.
of connections and installation of speakers continued apace.
for lifting were attached to the top before the last speaker was
attached the legs, et voilà!
The unit was complete. I wired in a speakon jack for the cable. The
total power requirement is 480 watts RMS, so...
got this amp for it that puts out 800 watts at 4 Ω in bridged mono
tested out fine. True to form, it sounds better without
natural reverb from a recording space, or artificial reverb added
post-production. I must give credit to my department (Music) at Wabash College for funding
this project. I am currently composing an
electroacoustic piece for bassoon, and will have other projects on deck
as I continue to experiment with using this system to diffuse
electronically produced sounds in a concert performance space.