Does anyone know how to make a dynamic normalizer?

I need to make one for my parent's TV so that the commercials don't deafen them! A dynamic normalizer smooths the volume levels between commercials, songs, etc. so you don't have to change the volume.

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bishopdante7 years ago
in the audio world this is called a compressor or limiter.


The key to doing this is measuring the program level of the signal and attenuating the level of the signal using this.

One of the cleverest ways of achieving this is to use a bulb and a light sensing variable resistor. This is called an "optical compressor"

Optical compressors use a light sensitive resistor (LDR) and a small lamp (LED or electroluminescent panel) to create changes in signal gain. This technique is believed by some to add smoother characteristics to the signal because the response times of the light and the resistor soften the attack and release.

You will find circuit diagrams on

Of course, the most usual method of achiving this is to just buy a compressor unit.



You should be able to pick up a bargain for about $20-$50.

Common decent but budget brands are: alesis, behringer, presonus, dbx, focusrite, samson.

Compressors can significantly alter the quality of the sound, they're one of the most crucial recording studio tools.

Hence, price-wise the sky is the limit, valve compressors can cost $10k.

I wouldn't suggest that you use one of these for the TV.

FYI the best are: TL Audio, Universal Audio, Manley Labs, Focusrite, Neve, Urei, API, Fairchild, Avalon, Chandler
Perhaps u could have a 'too low' and 'too high' threshold through a processor of some kind so when it reaches either of those levels it changes the volume accordingly?
Argon27 (author)  pufferboytbh7 years ago
Ah-Ha! You have just stated the exact definition of what I'm looking for! I know psp's have them but I'm not willing to wire the tv through the psp...yet.
Thanks Anyways :-)
Sandisk1duo8 years ago
you can remover the low frequency noise (the stuff you can hear thought a wall) with just a capacitor connected in series with the speakers the value of the capacitor depends on what frequencies you want to eliminate
Argon27 (author)  Sandisk1duo7 years ago
That's not quite what I'm looking for. A dynamic normalizer smooths the volume levels between commercials, songs, etc. so you don't have to change the volume. Thanks though! :-)