ccrome2 wrote: > The difference between 8000 and 44100 seems like a *TON*, and it is a > lot, but not as much as you think. Since you hear logarithmically, > you're really talking about about a 2.5 octave difference. You hear a > total of about 10 octaves (from 20 to 20000 Hz), so you're only knocking > off the top 25% of your hearing range. > > Bottom line is, the 'FM equivalent' or 'AM equivalent' are really just > best guesses, and not something you can count on.
On the best of days, with the best transmission, FM signals are limited to a max of 17kHz. The remaining 3kHz were thrown out when the modulation for stereo FM was defined back in the 50s. There was a time when FM stations would try to put out a reasonably clean 20hz to 17kHz signal, and there were audiophile tuners that worked hard at picking it all up. But in the past decade (or more) most stations have used the top to transmit assorted things like traffic information, Muzak, call letters, etc. and have gladly given away any pretense of sending out a real 20-17kHz signal. The primary audience for FM radio is in your car. With road noise, wind noise, etc., there is no way that even a 70 dB signal can be heard in a car. The stations all want maximum range, and part of getting that is to compress the hell out of the signal. Perhaps in some other countries, there is still serious musical quality in an FM signal, but its not been true in the US for two or more decades. When I was a DJ in the 70s, we used LPs and carts for music, jingles, etc. A radio station turntable and cartridge is nothing like a modern audiophile turntable. No $500 cartridge would last one shift of the DJ with all the back and forth, drop cues, etc. that was SOP in a station. I too would love to know what the best of the stations actually broadcast in the late 80s. -- Pat Farrell http://www.pfarrell.com/ _______________________________________________ Radio mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/radio
