Mysteries of compression

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JJ2013
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Mysteries of compression

Post by JJ2013 » Wed Mar 19, 2014 8:58 am

Hi y'all Audiophile and VoooooDooooo Gurus!

While reading up on compression I ran into the article posted on the web site below and found a lot of the information to be quite intriguing.
http://theproaudiofiles.com/dynamics-processing/

I would be particularly curious to learn what you may be thinking of the excerpt below, below the *************** line? Obviously Matthew Weiss is not discussing this topic in the context of eSSB but rather a recording studio so some of these findings may not be entirely relevant. What he writes about preamps is pretty significant I would think although the "bullet point" probably applies to preamps that have tubes in them......

Let me know what you guys think?

Cheers de JJ
NI2M
*******************************************

You are listening to a signal that has gone through at bare minimum 3 stages of compression — and more likely than not — closer to 6.

•The microphone capsule gains tension as the rappers voice pushes it — in other words — it pushes back. The more the rapper’s voice pushes in, the harder the capsule diaphragm pushes back. In other words, the louder the signal is hitting the capsule, the more reduction the capsule does to the signal. That’s compression! (It’s mild compression, but it’s still compression).
•Along the way through the microphone, you may hit a tube. Tubes have a non-linear response to voltage — the response is quite curved, and also changes the frequency balance of the signal. This is called saturation – which will tend to “round out” a signal, by reducing the loudest peaks. Compression! And before leaving the microphone, the signal may hit a transformer as well, which will saturate in a similar way… more compression.
•The preamp is going to have multiple stages of saturation – and often times, the more gain you give something — the deeper that saturation curve goes. In other words, the more you drive the signal at the preamp, the more compression the signal experiences.
•Then the sound has to actually come out of the speaker cones. Well, those speaker cones are going to build up tension when pushed further. See where this is going? This is called “cone compression”.

Ok – so this is a bit of a simplification – but there’s a point here. The point is that “compression” is always part of the signal. Some mics have less of it, some have more – same with speakers, tubes, transformers, etc. And they all do it in different ways. With tubes, people will talk about their saturation curves and %THD (total harmonic distortion — or frequency alterations). With mics, people will refer to how it “grabs” a sound — or more specifically — the sound’s shape.

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Post by Voodoo Guru » Mon Mar 24, 2014 2:50 am

Howdy JJ,
As he said, a very simplified explanation, but very true.
To add to that, there are many many different applications and ways to use compression some of which were stated in the previous thread...

http://www.wz5q.net/talkvoodoo/viewtopic.php?t=659

Take Care,
Voodoo Guru
From Deep in the IDD of the Sub-Harmonix Realm

JJ2013
Voodoo Audiophile
Posts: 141
Joined: Sat Apr 27, 2013 9:16 pm

Post by JJ2013 » Fri Mar 28, 2014 3:06 pm

Howdy VooDoo Guru!

I kinda guessed what you might say. Thanks! :D

JJ

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