Boston Audio Society
December 2012 Meeting
Time: 6PM Sunday, December 16, 2012
Place: At a home near Newton, (contact
BAS for directions)
Guest: Stephen Owades
Topic: BSO Broadcast Comparisons
Many BAS members have long appreciated the broadcast
concerts by the Boston Symphony Orchestra. The ways one can listen to these
concerts have multiplied in recent years, and we were asked by Lee Eiseman
of the Boston Musical Intelligencer (www.classical-scene.org)
to evaluate the sound quality of the available options. A team of BAS volunteers
(John S. Allen, David Hadaway, and Stephen Owades) recorded the live broadcast
on October 12, 2012 (a fine concert of Mendelssohns Violin Concerto
with Arabella Steinbacher and Shostakovichs Fourth Symphony, conducted
by Vladimir Jurowski) in all four formats: WCRB 99.5-FM analog, WCRB 99.5-HD
(96kbps), WGBH 89.7-HD2 (48kbps), and the WGBH web stream (128kbps MP3).
We then recorded it again in all four formats during the rebroadcast on
October 20. In addition, we have captured the on-demand web stream (also
128kbps MP3), and have obtained copies of the high-bit-rate BSO Concert
Channel stream (192kbps MP3) as well as CDs direct from the recording
room at Symphony Hall.
Stephen Owades is preparing sample selections from all
11 recordings, carefully level-matching them (with allowances for different
dynamic compression). We will be able to do double-blind comparisons among
these versions, and we should be able to draw some useful conclusions about
dynamic compression and limiting, noise levels, frequency balance, and any
artifacts that may be present.
Visual illustrations of the dynamic envelope and spectral
balance can be shown, as well as a diagram of the path the signal has taken
for each version. We hope to come to some conclusions about the relative
sound quality of these various versions and to examine the reasons why they
may sound different from one another.
All of these comparisons are separate from questions
about the original miking and mixing, since all the versions draw from the
same source mix. If time allows, we may also listen to some examples of
earlier broadcast material through some of the same channels, to see what
may have changed in these broadcasts recently.
Stephen Owades is a graduate of MIT with a degree in
Music and took a course in Architectural Acoustics taught by Robert Newman.
He is a former President of the Boston Audio Society. He is long time member
of the Boston Symphony's Tanglewood Festival Chorus.
John S. Allen will talk about technical measurements
of the different forms of broadcast.
After the meeting, guests are welcome to stay and audition
the elaborate and impressive surround system and the 14' video display.