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.
From: Kevin McMurtrie
Subject: Re: Is it Possible?
User-Agent: MT-NewsWatcher/3.2 (PPC Mac OS X)
Date: Mon, 13 Jan 2003 00:23:33 GMT
NNTP-Posting-Date: Sun, 12 Jan 2003 16:23:33 PST
In article ,
"Ken McDonald" wrote:
>I want to build a circuit to eliminate the center channel from a stereo
>input. I think I can do it by inverting one channel and sum it with the
>other channel. Or feed both inputs into a differential amplifier. The only
>problem is I end up with a mono output.
>What I really want is to eliminate the center channel and still have a
>separate left and right channel. Is it possible?
Not with simple linear circuits. The best you can do is to remove a
fraction of the common signal and send that to the center channel. It
works in moderation. The more it's done the more the sides become
inverted mono, as you mentioned.
Do a web search for surround sound decoders and center channel decoders.
A circuit is programmed with a set of rules for adjusting the levels of
each speaker to guess the sound placement. An encoder is designed to
help trigger those rules. The key word here is "guess." It works for
some kinds of audio but mangles others. Dolby has most of the patents
DVD offers six independant channels. There's no placement guessing.
The only limitation is that the sub channel has a 200Hz cut-off.
Speaker placement has a lot to do with all of this. Driving front and
rear speakers with plain two-channel stereo can sound better than
two-channel Dolby decoding when all the levels, echoes, and phases are
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup