zmix wrote on Thu, 13 April 2006 16:58 |
Ronny wrote on Thu, 13 April 2006 14:42 | ... -20dB threshold at 2:1 ratio is a -5dB gain reduction, my graph clearly shows that you are wrong and the statement that you continue to try and enforce about gain being increased below threshold.
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Falacious argument #952: You show a graph of a limiter and attempt to refute that a 'compressor' even exists.
If there is a rotation point at 0dB (as the 1a graph shows) a signal 10dB below this point will have a net gain of 5dB. THere is nothing incorrect about my assertion.
Quote: | I suggest that if you want to get into discussions about compression and limiting that you post your own experiences and not what you read on the internet.
| Now that's just rude...
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Your explanation that you weren't trying to be rude to me first is good enough for me, sorry that I took it wrong and was trying to be rude back.
I don't remember saying Morgan was incorrect, I said that he's not plotting his graph in the typical manner. The rotation point is merely 0dB input, 0dB output, the same 45 degree unity gain line that I'm talking about. I fail to see the rotation that he's talking about and I've never heard the term rotation used with compression. I assumed, maybe incorrectly that he was talking about the hinge point, where compression is applied.
I can't read the ratio numbers, but on graph 1a the middle input line, the hinge is at -20dB threshold, the gain difference is 10dB, this represents a 2:1 ratio maybe 3:1 ratio as it's not clear. 10dB gain reduction at -20dB not 5dB. Gain reduction "does not start at -0dB input, -0dB output", Z. It starts at the threshold, you can forget about the rotation point in his graph as being pertinent to what I'm relating it's unity gain, meaning the input and output are "exactly" the same, "no gain reduction", the diagonal 45 degree "unity gain line" intersects the rotation point.
You said my graph is a limiter. No, it's a compressor with a 2:1 ratio. At -20dB threshold and 2:1 ratio, the signal will be reduced in gain by -10dB when the threshold is met and the compressor comes on. You may be associating the hard knee with a limiter. Knee on a brick wall limiter is hard, as I mentioned, but I use hard knees on lower ratio's all of the time, it's entirely material dependent and what I want to do that determines knee settings for me.
Your graphs clearly show that no gain increase is below the threhold on all 3 input lines. Please understand that a line that intersects the bottom left and top right corner of each plot square signifies "unity" gain, "no compression". The graphs don't support your argument that gain increases below threshold, it does not and they clearly show that I'm correct. What Bob is saying and correctly so, is that gain increases "on release" of the compressor NOT when the signal is below threshold and the release time is over. The signal is again at unity gain and the compressor is no longer effecting the signal.