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conn
Pores [or eter deren)
souACE
Tramsteroer
1K hee 10K oben
24
14 to find out what devices are compatible. If you
want to understand a little more about the "dB",
read the note below.
NOTE:
For those
who
are
interested,
dB
describes a ratio, not an absolute number. Twice
the voltage or sound pressure level, in dB, is an
increase of 6 dB, and half the voltage a decrease
of 6 OB. Ten times the voltage is a change of +20
dB, and 1/10 the voltage is a change of -20 dB.
(Unlike voltage or sound pressure level, twice the
power is +3 dB, and ten times the power is +10dB.
Placing certain letters behind the "dB" gives the
OB values a specific reference instead of ageneral
ratio. For instance,0dBm=0.775 volts, and other
dBm numbers can be calculated to correspond to
exact voltage values. The 0OdBV reference is 1volt.
The 0 dB SPL reference is 0.0002 dynes/square
centimeter
(20 micro-Pascals*).
The
0 dBm
reference is 1 milliwatt (which happens to be
0.775 volts only when the circuit impedance is
exactly 600 ohms). The significant point is that
"dB" always describes a ratio, so an increase or
decrease
of so many
dB does
not
always
represent the same
number
of volts, Watts,
dynes/cm', etc.
* The Pascal is amore recent unit of Sound Pressure Level.
1 Pascal (abbreviated "Pa™) is equal to 10 dynes/cm?
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