Page 37 - 2013 Spring

MUSIC, ROOMS AND LISTENERS
SCIENCE IN THE CREATION AND DELIVERY OF AUDIO ART
Floyd E. Toole
1301 King James Court Oak Park, California
Fig.1 (a) The “circle of confusion” at the core of the audio industry and (b) the two domains that must exhibit fundamental similarities if listeners are to hear the art that was created. From Toole, 2008.
Sound sources and rooms are inter- Could the “best” music is mundanely delivered through
active systems. Concert halls and
auditoriums are integral parts of
live performances. Because architects
thrive on distinctive designs, the ven-
ues are all different, making each com-
bination of conductor, orchestra and
hall a unique auditory event, never,
perhaps, to be repeated again. Audiences expect and embrace the spatial and timbral idiosyncrasies and music is enjoyed. Generations of trial and error, and scientific research, have provided guidance about how to design halls that maximize pleasure while not exceeding the limits of lis- tener adaptation. With care, the art —the performance—is satisfactorily delivered to audiences. The music may be rel- atively constant, but the auditory experience is not. This is sound production. It is what it is at the time, and it may never be again.
Elaborately illuminated and sound reinforced, large- venue popular music performances begin with microphones that sample the extreme near field of individual voices and instruments. Gigantic loudspeaker arrays make no effort to place the music into a natural acoustical context; in fact, they are designed to address the audience, avoiding the room boundaries. Much of the artistry is the responsibility of the “front-of-house” mixer, who sits at a console determining how much we hear from each of the musicians on stage, while manipulating signal-processing parameters that affect perceptions of timbre, space and dynamic range. This person can make or break a performance, regardless of how well the musicians perform, how excellent is the inherent design of the loudspeaker system, or the quality of the acoustical envi- ronment. This also is sound production. It is what it is at the time, and it may never be again.
As enjoyable as live performances are, the bulk of our
36 Acoustics Today, April 2013
loudspeaker simply be
the one perceived to be
the “least bad?”
loudspeakers in our homes, cars, in cin- emas, or through headphones or ear- buds as we walk the dog or travel. The music itself has been captured through microphones that sample portions of the near and far fields of voices and musical instruments, with or without
additional information from acoustical settings. These streams of data are manipulated in control rooms by record- ing engineers who decide precisely what we, the audience, will hear of those sounds. Voices and instruments are modi- fied using any of the nearly countless electronic processing algorithms. This is done while monitoring the experience through specific loudspeakers in a specific room. Normally this is done in two channels—stereo. This is the creation of the art, the original performance; it is sound production. Unless the audience has playback—i.e. sound reproduction— capabilities that precisely duplicate this situation, this is the only time it will be heard. It is what it is at the time, and it may never be again. (Figure 1)
There are no standards for loudspeakers or rooms used in the music industry. Individual studio designers, owners and recording engineers have expectations of what they want to hear in control rooms. There are large differences among them, especially with the advent of home studios. Recording engineers attempt to anticipate what consumers are hearing, trying out their mixes in cars and over inexpensive systems in vogue at the time. Some choose to use monitor loudspeakers that they think portray the characteristics of “average” con- sumer playback systems. The problem with this approach is that it is not possible to standardize “bad sound.” In reality, most playback systems, at all prices, aspire to be neutral. For a variety of reasons they may fail, and when they do they fail in infinite different ways. After nearly 40 years of examining