Automatic Television Volume Control

[[email protected]]

Anyone out there with a circuit for controlling the TV volume so that
it doesn't blare during commercials? I know these things are sold but
I'm cheap and want to make my own.
Thanks.

 

[mc]

It is sometimes called a "compander" - look for it under that name.

 

[Charles Schuler]

Anyone out there with a circuit for controlling the TV volume so that
it doesn't blare during commercials? I know these things are sold but
I'm cheap and want to make my own.
Thanks.

Practically speaking, just keep the remote handy and mute them. Commercials
use level processing where the peak audio voltage is not all that high but
the average audio is much higher. It's called compression, among other
things and is truly a pain in the ear!

 

[Mark Jones]

Practically speaking, just keep the remote handy and mute them. Commercials
use level processing where the peak audio voltage is not all that high but
the average audio is much higher. It's called compression, among other
things and is truly a pain in the ear!

So, if you use another compressor, combined with a limiter, you can
effectively set a "normal" volume and commercials will no longer
blare. The problem arises in how to implement the design. Are you
willing to open up your TV, dissect the audio amplifier circuitry,
patch in the compressor, and reassemble the TV? Because I've not seen
a line-level compressor (which you can connect directly between the
speakers.) All compressors are low-level devices. If you do not use
your TV speakers but instead use surround sound or other speakers,
then it might be possible to patch the compressor between whatever is
feeding the audio to the amplifier.

 

[Kevin Aylward]

Practically speaking, just keep the remote handy and mute them.
Commercials use level processing where the peak audio voltage is not
all that high but the average audio is much higher. It's called
compression, among other things and is truly a pain in the ear!

I have digital cable, and there is no way its compression in this
method. The sound is truly turned up much louder, and it is very, very
irritating indeed.

Kevin Aylward
[email protected]
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[john jardine]

I have digital cable, and there is no way its compression in this
method. The sound is truly turned up much louder, and it is very, very
irritating indeed.

I only get the normal 5 channels but yes, the ads have gotten worse over the
last couple of years (say +3dB).
I reckon the problem is due to two factors.

A] The massive compression that they recently seem to have been able to
leverage in. During the ad's just listen for those few (nS!) where no one is
talking. You can hear significant background mush.

B] Incompetance and couldn't care less attitudes of all the modern brand of
transmission engineers, causing highly variable VU levels to be put out
during normal programming.

Channel 5 maybe but at one time the Beeb would have sacked their lot
en-masse.

regards
john

 

[John Woodgate]

I read in sci.electronics.design that john jardine

B] Incompetance and couldn't care less attitudes of all the modern brand
of transmission engineers, causing highly variable VU levels to be put
out during normal programming.

The BBC doesn't use vu-indicators. It uses peak programme meters, which
are much better. But these days, no-one looks at them. -(

 

[Spajky]

Anyone out there with a circuit for controlling the TV volume so that
it doesn't blare during commercials? I know these things are sold but
I'm cheap and want to make my own.

IMHO,
maybe a circuit [serially connected chain of Resistor (1k)- a serial
LC tank (1kHz) - 2 antiparallel schottky diodes] connected to an audio
amplifier´s input of a TV parallel to signal & ground before the
volume chip /pot/trimmer/, would mild the bumping up the commercials
sounds.

The idea is that since the sound of commercials is highly compressed
by dinamics, The main bothering frequencies that hit the ears is
around 1KHz (-/+ 2 octaves & higher volume than normal program) would
be limited futher by shothing them more to the ground. This should not
effect to much on the main program sound ...

this idea woud need some experimenting IMHO ...

 

[Mike]

Anyone out there with a circuit for controlling the TV volume so that
it doesn't blare during commercials? I know these things are sold but
I'm cheap and want to make my own.
Thanks.

You might try this.
http://www.electronics.teleactivities.net/circuits/amplifiers/a5.html
I just wired it up on a breadboard and it seems to work ok.
I used a TL071 instead of an LM741 and an MPF5245 instead of a 2N3819.
I also powered it from +-12v instead of +-9v.
You'll want a level control on the output.
Using a 39k input resistor I varied the input from 25mv to 1v PP and
the output varied from about 5.4 to 10v pp.

Mike