Seems a good idea to break this info out into a separate topic from
the other thread which wandered off into other subjects.
Joe Hardy, also a member of this Forum, has posted at the VTPO
Yahoo list the following information and comments:
"From an email discussion with Ethan Wigner (posted with his permission):
""Even aside from any wind noise, no room you record in has a dynamic
range approaching 96 dB unless maybe you stuffed the microphone into
the pipe openings. [ed: in which case one would get some real noise!]
The main noise that will accumulate from playing many samples at once
is the background noise in each individual Wave file sample. Which, again,
I assume will be dominated by the room's ambient noise level.
A blind test is always useful, but this can be proven more easily simply by
reading the residual noise level on a VU meter for portions of the samples
where there's only silence. Are the people in this forum creating organ samples?
All you need is one 24-bit five-second clip of the room tone with no organ sounding.
Make a copy of that file reduced to 16 bits, then load up maybe 20 tracks of each
into a DAW program and press play. If all 20 24-bit files go to one output bus, and
all 20 16-bit files go to another, just read the playback level meters for each bus.
If the residual noise for both buses is the same, that proves the lower *potential*
noise from using 24 bits is not needed or being used.""
The 96 dB headroom provided by 16 bits is far more than the best professional
studio analog tape recorders which could muster perhaps 75 dB, not quite as
good as 13 bit resolution. Then you have the ambient noise which exists in
even the quietest rooms, the self-noise of the microphone, the noise in the
mic preamps, all of which gets included in the raw samples. Then of course
there is the organ wind noise.
It seems possible that a very quiet wet sampled classical organ may benefit from
loading in 24 bits when a large number of pipes are played and the room's natural
reverb decays fully. A test that would demonstrate whether or not there is any
benefit to the higher bit rate could be accomplished by loading the organ in 24 bits,
pull every available stop and coupler, open the swells, briefly play an eight note chord
and let the sound decay until the reverberation has completely decayed. Record this
directly to a WAV file using Hauptwerk's facility. Repeat with the organ loaded in 16 bits.
If there's a difference, it should be audible and measurable.
I do hope that everyone who has the slightest interest in this subject matter will watch
the entire 60 minute AES Audio Myth Workshop video:
http://www.youtube.com/watch?v=BYTlN6wjcvQThe demonstrations of "expectation bias" are especially powerful."
End of quotes from Joe Hardy, and his from Ethan Wigner.
I have had the large 93 rank "wet" PAB sample set loaded in HW using
the "default" 16 bit loading with only the first sample loops loaded.
The result is a fine organ, but I would prefer to also have all the
sample loops. But, my 12 GB of RAM are too few.
So, this morning I am re-loading the PAB in only 14-bit and with all
the sample loops as well. With 16-bit loading, I am using 66% of the RAM
required to load at 24 bit (or I would have needed just over 18 GB
to load in 24 bit and still only one sample loop. With 14 bit loading, I
use 8% less RAM for the sample storage, or about 1 GB more.
I reasoned that this 1 GB more available RAM would allow me to again
try to load all the sample loops provided by Inspired Acoustics of the
organ pipes in this very large organ. It is now loaded; I will go play
some music now and report back about my satisfaction, or not with
this experiments results. If Ethan Wigner's arguments are correct,
the organ should sound just fine.
By the way, I believe the reason that his work and conclusions are
correct is that noise quantities do NOT add coherently, as one
learns when going into information transfer topics. At least,
as I believe I was taught so long ago in school.