"SoCal Tom" wrote in message
...

"SFTV_troy" blabbed:
... this new receiving technique would not improve the sound
(it would still be limited from 100-6000 hertz), but would only reduce
interference.

At least in the States, AM & FM broadcasting is limited to 50 Hz to 15KHz.

AM is restricted by the NRSC standard to a 10 kHz brick wall.

Digital broadcasting is limited to under 20 Hz to over 20KHz, or
basically, the extent of the normal human hearing range.

If you're listening to 100 to 6,000 Hz, you're listening to a poor
telephone connection.

Bob Orban, on the NRSC committee, found that consumer radios almost without
exception, rolled off by at least 10 db by 4.2 kHz, and passed practically
nothing over 5 kHz.