TV Commercials are still LOUDER than the programs.

[audioguru]

I see a lot of talk about audio compressors, what about an audio enbigger.

The opposite of an audio compressor is an audio expander. It expands the dynamic range that was reduced by the compressor. But it is difficult to set up the threshold level and the amount of expansion.

Movies an other programs use to be Class A amplification, commercials were Class B amplification, not sure they still are. Class B sounds louder than Class A. Run all the sound through a Class B amp and use a feed back circuit to monitor the output so it is automatically amplified to the same level.

No.
A program is not Class-A or Class-B. Instead an audio output type is Class-A that wastes a lot of power supply current all the time and has low distortion or Class-AB that conducts a small amount of current all the time and also has low distortion.
Class-B produces awful-sounding crossover distortion because the output transistors are not biased for an audio amplifier. The output level for Class-B is a little less than the other classes and it produces no sound at low levels.

 

[Mr RB]

I see a lot of talk about audio compressors, what about an audio enbigger. LOL, is that a cool name for it. ...
... use a feed back circuit to monitor the output so it is automatically amplified to the same level.
...

What you described is actually a compressor.

It "compresses the dynamic range" so it makes the loud and quiet sounds more similar in volume to each other. ie; makes the loud bits quieter and the quiet bits louder, or any combination.

These threads crop up from time to time, and everyone talks about how great it would be to have one but nobody ever wants to design and build one.

 

[BobW]

Have a look at this:
http://www.tompolk.com/hobbies/automaticvolumeleveler/avc.html

 

[audioguru]

Have a look at this:
http://www.tompolk.com/hobbies/automaticvolumeleveler/avc.html

Audio experts say that an LDR is too slow to attenuate blasting audio.
Here is a fast acting project and a link to many other Voltage Controlled Amplifiers:
**broken link removed**

 

[Mr RB]

Yeah I agree, an LDR is going back to the dark ages in terms of compressor technology.

AG, your last link is to "peak limitiers" for saving amps and speakers, not really good for general dynamic compression.

 

[audioguru]

I posted the very fast peak limiter circuit as an opposite to the very slow LDR compressor because my local TV station used a very slow compressor for years. The first word, a person taking a breath before speaking or a background sound came blasting before the compressor reduced the gain.