the widest dynamic range you're ever
likely to encounter. The sound levels at
the microphones (not in the audience)
may range from 40 dB SPL (the audience,
wind, and traffic noise at the mic
during a very quiet, momentary pause)
to 130 dB SPL (beyond the threshold of
pain... but then, the performer is
shouting into the mic, not into someone's.
ear). What is the dynamic range
of this concert? It is obtained by
subtracting the noise floor from the
peak levels:
Dynamic Range...
= (Peak Level) - (Noise Floor)
= 130 dB SPL - 40 dB SPL
=90dB
The concert has a 90 dB dynamic
range at the microphone.
NOTE: We specified the dynamic
range injust plain "dB," not in "dB
SPL." Remember, dB is a ratio and
~n this case we are simply des~bmg
the relationship of 130 dB SPL
to 40 dB SPL; the difference is
90 dB, but that has nothing at all
to do with a sound level of 90 dB
SPL referenced to 0.0002 dynes per
cm2. Dynami.c range I.S nearly
always specified in dB, and should
never be expressed in dB SPL,
dBm, dBu or any other specifically
referenced dB value.
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