Re: GG: microphone positions

[John Hill <jphill@home.com>]

Mike Flemmer wrote:

> > I noticed whilst watching some films of Glenn Gould, that the microphone for
> > the piano is generally on a stand on the floor - facing directly up at the
> > soundboard.

In one of the Bruno M. vids, you can see some PZMs (Pressure Zone Mics) on
the floor, just out from the front of the soundboard.  This was not, in fact,
the typical
mic placement for Gould's studio recording work.  Boundary mics, like the PZMs,
are supposed to prevent comb-filtering from surface reflections around the mics.
In fact, their sound is usually considered inferior to high quality air mics
and few
classical engineers use boundary mics in their recordings.  Generally, under-the-
piano micing gives a boomy, thick sound.  Plus, of course, you get lots of pedal
noises (as opposed to hammer and damper felt noises).  I noticed that in this
particular video, the PZMs were being used *with* a pair of traditional air mics.
Hence, the PZMs may not have even been in the mix.  They could have been
props or perhaps the engineers were trying them out and mixing them in at a
low level.

> Are the microphones under the piano, facing straight up?   The microphonesin the
> Goldberg 1981 video seem to be standing on both sides of
> the piano facing up at the ceiling (but they are probably omni-directional,
> so it probably doesn't matter which way the point).

Gould owned a number of Neumann U87s, which were the mics he and Kazdin
typically used for session recordings.  These are large diaphram condensers and
their polar patterns can be switched between omni, cardioid and figure-8.  The 
configurations used in the videos show a near-coincident array, which probably
means they were in the cardioid setting.  I'm not aware of any session
pictures from
the Eaton Auditorium surviving, which show mic placements.  It's *possible* that
spaced omnis could have been used, but that's doubtful, particularly for the video
sessions.  Mono compatibility is critical for video and broadcast work; 
spaced omnis
(or spaced PZMs, for that matter) generally do not sum very well into mono.

The mic technique used in the ON THE RECORD session is very different.
But that, of course, was from a much earlier time and was done in the 30th St.
Columbia Studios in NYC.

> I find the audio in the Goldbergs to be incredible.  Can someone tell
> me if the audio in all of the other Collection videos are stereo or mono?

The later Bruno M. vids (A Question of Instrument, etc.) are stereo.  They
show U87s
used in an ORTF or near-coincident array.  However, the stereo width is predictably
conservative, with a strong mono center component.  Again, since lots of viewers
at that time were listening to one, small TV speaker in their sets, the
engineers had to
be careful not to go too wild with the stereo spread.  Besides, close-miked piano
with wide, hammer-oriented imaging is an approach much more common to jazz
recording than "classical" piano music.  GG did, however, favor a much closer
perspective than was common for classical piano miking at that time.

Hope this helps.

jh