[Asterisk-Users] Woodpeckers

Steve Underwood steveu at coppice.org
Fri Feb 20 07:19:16 MST 2004


Nick Bachmann wrote:

>>Hi Michael,
>>
>>Michael Welter wrote:
>>    
>>
>>> the codecs I use?  Filter-out everything between, say, 55 and 65Hz?
>>>      
>>>
>>Notching may not be that effective, as it will not deal with the
>>harmonics. The analogue to digital converter should already be
>>filtering  below 300Hz, so you probably have quite a lot of hum if it
>>    
>>
>
>300Hz is pretty high to filter out... it's still well within the rage of
>voices. To compare, 300Hz is about a diatonic concert D.
>  
>
Can you read? ALL PHONE CALLS ARE FILTERED HARD BELOW 300Hz. THAT IS HOW 
ALL TELEPHONY HAS WORKED SINCE THE TIME OF ALEXANDER GRAHAM BELL.

Regards,
Steve




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