RNC - Why does ratio affect tone?

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Gamelan

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RNC is my only outboard compressor, so I don't know if other compressors do this. The greater the ratio, the less high frequencies. Is this an intentional "warmth" feature or a natural product of compression? For instance, if I set the threshold to -1db, attack and release set fastest, then send a sound peaking at -1db, turning the ratio from 1:1 to 20:1 sounds like dialing a tone control, with the highs becoming muffled as the ratio increases. Theoretically, at these settings shouldn't the difference between 1:1 and 20:1 be more or less inaudible? Maybe there is something I'm not understanding here. If a sound exceeds the threshold by 1db at a ratio of 2:1, then that sound would be reduced by 0.5db, right? If the ratio is 20:1 that same sound would be reduced 0.95 db. So my question is, why does such a small difference in volume adjustment alter the spectrum of the sound?
 
Whether it’s achieved with tubes, tape, or solid state, greater compression = a reduction in high frequencies. So yeah, that’s normal.
 
The peaks in music are most often caused by high frequency spikes. Obviously, a high ratio is going to have a stronger effect on those short high spikes, bringing them down, thus lowering those high end sounds.
 
It's gonna make some difference as to where exactly you place that compressor in the chain of things as well. Generally speaking I don't use over a 4:1 ratio unless it's absolutly necassary and keep in mind that if you get to 8:1 you're in the limiting range of things which is where it is really gonna crunch things down. Let the threshold level and output levels dictact more so than ratio.
 
yeah, what everyone else has said. also, if you use the supernice mode of the rnc, the reduction of treble frequencies will be less noticeable (although still there).
 
So what are you trying to compress Gamelan?? Is it sometype of percussion by chance?
T
 
Yup, it's mostly for drums. I would like to get a little hotter signal to bring out detail in the snare. I also do some very peaky gamelan stuff with hard wood hammers on bronze.
 
Gamelan said:
RNC is my only outboard compressor, so I don't know if other compressors do this. The greater the ratio, the less high frequencies. Is this an intentional "warmth" feature or a natural product of compression? For instance, if I set the threshold to -1db, attack and release set fastest, then send a sound peaking at -1db, turning the ratio from 1:1 to 20:1 sounds like dialing a tone control, with the highs becoming muffled as the ratio increases. Theoretically, at these settings shouldn't the difference between 1:1 and 20:1 be more or less inaudible? Maybe there is something I'm not understanding here. If a sound exceeds the threshold by 1db at a ratio of 2:1, then that sound would be reduced by 0.5db, right? If the ratio is 20:1 that same sound would be reduced 0.95 db. So my question is, why does such a small difference in volume adjustment alter the spectrum of the sound?
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muwahahahahaha
 
mwahahah, is maybe for the use of compression @ +10:1 ratio will limit . So in essence it will kill those high end detials you are looking to boost.
Try 2:1 thru 6:1 and play with the threshold. And back off with the attack. RNC is pretty quick. On percussive stuff I go about 11 or 12 oclock (2-6) ms to let the transients through, then play with the release/gain.
What happened to EQ?
T
 
Didn't mean I was trying to get a good drum sound at 20:1. Just a point of reference that even with no gain reduction at all the higher ratio knocks out the highs. Still not understanding why that is, but I'll catch on eventually.
 
Gamelan said:
Didn't mean I was trying to get a good drum sound at 20:1. Just a point of reference that even with no gain reduction at all the higher ratio knocks out the highs. Still not understanding why that is, but I'll catch on eventually.
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Some high frequency peaks only last for a few cycles and won't trigger the meter. The higher ratio does catch them and lower them. Some high frequency peaks can exceed a zero threshold without triggering the meter. That's why the highs are being attenuated. Also, if the release is set long, the compressor is still operating long past the peak.

And oh yeah, what Chessrock says in the next post (right below this one).
 
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If it's killing the high frequency definition/detail, then your attack is probably too fast.

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chessrock said:
If it's killing the high frequency definition/detail, then your attack is probably too fast.

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Exactly, the way I was taught to use a compressor: how slow and how fast your attack and release times are set at, determines which frequencies get compressed. The ratio and threshold determines how much the signal is compressed and when it kicks in.
 
Harvey Gerst said:
Some high frequency peaks only last for a few cycles and won't trigger the meter. The higher ratio does catch them and lower them. Some high frequency peaks can exceed a zero threshold without triggering the meter. That's why the highs are being attenuated. Also, if the release is set long, the compressor is still operating long past the peak.

And oh yeah, what Chessrock says in the next post (right below this one).
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Very interesting. Think I'm getting it. So, if a signal is peaking the meters, there also could be faster transient peaks being clipped off inaudibly? Think I'm gonna turn my levels down. Thanks! When are they going to invent meters that show everything as it really is? I depend on meters (too much) often recording myself so I can't listen from the control room until after the fact. All I can do is play and watch the meters and then adjust, etc. Get an engineer, I know. Anybody want to work for free? hehe
 
Harvey Gerst said:
And oh yeah, what Chessrock says in the next post (right below this one).
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Not only is he extremely helpful, but psychic too!
 
Gamelan said:
Very interesting. Think I'm getting it. So, if a signal is peaking the meters, there also could be faster transient peaks being clipped off inaudibly? Think I'm gonna turn my levels down. Thanks! When are they going to invent meters that show everything as it really is? I depend on meters (too much) often recording myself so I can't listen from the control room until after the fact. All I can do is play and watch the meters and then adjust, etc. Get an engineer, I know. Anybody want to work for free? hehe
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I'm not sure this falls correctly into this meters/cause and effect scenario, but try your 'fast attack dulls but doesn't show much on the meter' with a fast release. Then slow the release down. It should show more then.
Wayne
 
Too slow of a release time can also smear the detail quite a bit. Particularly if it's an up-tempo track. Too quick of a release time can cause audible pumping (which can sometimes be cool, depending on the situation) ... or it can be counter-productive altogether. It's all about getting the setting appropriate for the situation. You get an ear for it after a while.

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