The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
Subject: Re: audio line specifications
References: <3DEE2757.EE79B063@crf.canon.fr> <3DEFD744.3A2D8C8D@gv.net>
X-Newsreader: Forte Agent 1.92/32.572
Date: Fri, 06 Dec 2002 18:38:25 -0500
NNTP-Posting-Date: Fri, 06 Dec 2002 18:38:24 EST
Organization: Bell Sympatico
On Sat, 7 Dec 2002 08:19:22 +1100, "Phil Allison"
>"John Woodgate" wrote in message
>> I read in sci.electronics.design that Phil Allison
>> wrote (in ) about 'audio
>> line specifications', on Fri, 6 Dec 2002:
>> >If you need a ( twisted pair)
>> >balanced audio line to have a flat response over distances of 100 metres
>> >more then correct termination of the line is important.
>> What impedance is a 'correct termination' of such a line at audio
> ** Nice trap question from JW.
> The "correct termination" is one that renders the response flat.
>The maker may specify a resistance value or you may have to do some tests
>with square waves and a CRO.
> A resistor of 100 - 150 ohms is a good starting point. If there
>is a transformer driving the line then that will make it more interesting.
> ................... Phil
I guess we have to go back to basics
You are confusing impedance matching with equalization.
The only purpose of matching the generator ( in this case the
amplifier and the line ) is to maximize the transference of power.
To maximize transfer of power the impedance should be equal
To maximize voltage transfer, the input impedance should be much
higher than the output impedance.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup