THE
A MISSED
by Mark
B. Anstendig
©1996 The Anstendig
Institute
The
San Francisco Opera House has one of the most uneven acoustics in the world and
fixing it would cost only a fraction of the multi-millions of dollars presently
being spent on the building's renovation and seismic retrofit. Bathrooms,
dining areas, seats, carpets, and other areas that have nothing to do with the
building's purpose are all being renovated. Yet not a penny is being spent on
the very reason for the building's existence: the sound.
Before
the bad acoustic of Davies Hall usurped all the attention, the “in,” joke in
The
most expensive seats, the box seats along the sides of the house, have the
worst sound. On the right side, the listener hears mainly first-order overtones
of instruments on the opposite, left side of the pit or stage. The sound is
almost devoid of the fundamental tones that the musicians are actually playing.
When the violins are playing, which is most of the time, their overtones drown
out almost everything else. The boxes on the left similarly hear mostly
first-order overtones from instruments on the right. The fundamentals are
drowned out. Tympani overtones and overtones from the lower instruments
overwhelm everything else. The imbalance is so strong, and the result so
confusing to the ear that the music is disfigured. The listener does not hear,
as he should, what the musicians themselves are playing and hearing.
The
right and left sides of the first ten or so rows of the orchestra sections
suffer from the same anomalies, with the sound slowly improving farther back in
the hall. The center of those rows has a better, though not excellent sound.
The sound improves towards the center of the orchestra sections, and the back
sections under the balconies have good sound. In the standing room area, at the
back of the hall, the volume level is much lower, but the sound quality is
excellent.
Seats
in the various levels in the back of the hall above the orchestra level have
better sound, improving further back. The standing room areas at the very back
of these levels have the best, most homogeneous sound of all.
The
reason for these acoustic anomalies is the large sections of bare, strongly
reflecting walls on either side of the hall directly in front of the stage,
between the proscenium and the first boxes. These walls continue back, with
only the boxes to break them up. The acoustic anomalies occur because higher
and lower frequencies radiate differently. Higher frequencies radiate more in
straight lines in the direction they are aimed, while lower frequencies radiate
less direction specifically, and more in all directions. Reflecting walls
increase the higher frequencies more than lower frequencies, because of
differences in the way those frequencies radiate: the more directly radiating,
higher frequencies that would not have reached the listener are reflected back
into the hall more strongly than the more diffusely radiating lower
frequencies. Since harmonics are higher frequencies than fundamentals, these walls
are the reason for the emphasis of overtones.
The
solution for the uneven acoustic would be to increase the sound-absorbency of
the main reflecting walls, and possibly the ceiling. Because of the
uncomplicated layout of the hall and easy access to reflecting areas, a good
acoustician could easily make the hall one of the acoustically best in the
world.
During
the renovation The Anstendig Institute called the Opera House to inquire about
corrections to the acoustic. The administrative officer disagreed that the
acoustic was bad, saying that it was a matter of opinion. The poor acoustic of
large sections of the Opera House auditorium is a scientifically measurable
reality, not opinion. However, after a century of bad, distorted sound
reproduction1 and sound reinforcement2 as its main source
of music, the public has lost its ability to distinguish between distorted and
correct, undistorted sound quality.
Society
urgently needs sources of undistorted, natural sound as a frame of reference to
determine and adjust the correct sound quality of its various electronic sound
sources. The San Francisco Opera House, as a non-profit, publicly supported
organization, has an obligation to become such a reference point, especially
when millions of dollars are being spent on renovations. Yet it appears doomed
to remain an acoustic anomaly and neither the public nor its administration nor
its funders seem to realize it.
1
See our papers on sound-reproduction.
2
Sound reinforcement is the name for all amplified live sound.
The
Anstendig Institute is a non-profit research and educational institute that
studies the vibrational influences in our environment, particularly those of
sights and sound, and how they affect sensory
perception. Its papers on sound reproduction, problems of focusing in
photography, psychology of hearing and seeing, and erratic vibrational
influences that affect our lives are widely distributed throughout the world.
All are available free of charge.