On Sun, 08 Apr 2007 01:35:01 GMT, james wrote
in :
On 6 Apr 2007 17:10:39 -0700, "Telstar Electronics"
wrote:
+++ 100Hz?????
+++ That is a subaudible frequency.
+++ How could anyone detect it without a scope?
+++
+++ james
+++
+++If you can't hear 100Hz... you need to get your ears checked Jim.
+++
+++www.telstar-electronics.com
+++
**********
Obvisously you lack the knowledge of what is the subtle difference
between audible and audio frequency. Also I did forget that CB radios
are not necessarily well designed radios. In a well designed radio,
any audio frequency below 300Hz is considered subaudible.
Why? Because the power density in the human voice below 300Hz is
negligible.
Hogwash. The .3-3kHz limits were standardized (by the military)
because researchers discovered, over half a century ago, that the
bandwidth carried the majority of -intelligibility- in the human
voice. IOW, by limiting the frequency range of the vocal spectrum,
transmitted speech can be understood using much less power than when
transmitting using the full voice bandwidth.
Most well designed receivers for communications purposes
do not have audio response below 300 Hz.
Hmmm..... my Onkyo is a well-designed receiver for communications
purposes and it is flat down to 2 Hz.....
Also human hearing threshold
increases as the frequency decreases below 300Hz.
Huh? When was the last time you looked at a weighted equalization
curve?
That is the source
of the audio freq uency needs to have a larger PSL in order for it to
be heard. Sensitivity to audio frequency in Humans is not flat like
that of speakers and some sound systems. Instead SPL, Sound Pressure
Level, needs to increase as frequency decreases below 300Hz to gain
the recognition. For most Humans the power of a 20Hz signal needs to
be about 30dB higher than that of 100Hz.
That depends on how much you bump up the boom on those 24" JBLs inside
your sub-compact riceburner. The sad thing is that when those kids go
deaf they will collect welfare for their self-inflicted disability.