• SONAR
  • PC4K Compressor HPF?
2013/11/25 04:40:51
aglewis723
Hello,

Can someone enlighten me exactly what this red knob does?

Thank You,
Adam
2013/11/25 05:13:55
TS
"High Pass.
Applies a High Pass filter to the sidechain input. The valid range is OFF to 2 kHz."
 
X2 Reference Guide, page 980
2013/11/25 14:10:06
aglewis723
TS
"High Pass.
Applies a High Pass filter to the sidechain input. The valid range is OFF to 2 kHz."
 
X2 Reference Guide, page 980


Thanks for the reply.  I did read that, but don't totally understand what it means.   What is happening when its all the way to the right (Default State) and then all the way to the left?   
 
I notice in a kick/bass situation, more gain reduction is applied by turning it to the left, but I just don't understand why.  
 
Sorry if it's a newbie question.
 
Adam
2013/11/25 14:14:23
Keni
A high pass filter does exactly that... It rolls off low end and allows the highs to pass... The knob adjusts the chosen frequency to use as the roll off point and will then reduce the gain from that frequency down at its pre-defined ratio...

Keni
2013/11/25 14:22:17
aglewis723
Keni
A high pass filter does exactly that... It rolls off low end and allows the highs to pass... The knob adjusts the chosen frequency to use as the roll off point and will then reduce the gain from that frequency down at its pre-defined ratio...

Keni

So if I move it to the left, it only compresses based on the highs?   Is it compressing only those frequencies?  I guess im not understanding the concept of what is coming in, what is being used to compress and what frequencies it is compressing.
 
I understand what an HPF is, but not how it relates to this compressor.

Thanks,
Adam
2013/11/25 14:32:55
scook
It is filtering the side-chain signal, so it allows you to control to what extent low frequency information triggers the compressor. The compressor is still compressing the full audio signal.
2013/11/25 14:48:13
soundsubs
one of the intricacies of a compressor is that the input signal going into it affects how it works!
bass frequencies are stronger than are high frequencies-- that's why we hear thunder from miles away but not the clap of the lightning-- and therefore trigger the compressor to work harder, and can result in squashing a mix to death.  
a sidechain hipass on a compressor helps compensate for this and will allow the bass frequencies to go through untouched, while the rest of the frequencies above gets compression. in dance music, this is key, because the kick/bass don't always need to be compressed in a mix; they need to stand out.
starting from OFF-- meaning NO sidechaining compression is happening, the whole mix will be compressed.
turning the knob fully the other way will gradually raise the cutoff frequency for what gets compressed.
 
in the sonitus compressor, you can sidechain in a different way by putting the compressor on a sustaining pad or string sound. then you send a kick into the sidechain input and it will dip the strings down in volume every time it "hears" the kick drum. also used heavily in dance music for that pumping/throbbing sound.
2013/11/25 19:48:47
cliffr
Sorry , much of the information in the above post is very inaccurate and I imagine would only confuse you.
 
For example, thsi control has no affect on what range of frequencies get compressed at all.
The whole input signal is always compressed - the entire frequency range.
Meaning that when compression is applied, it affects the entire signal.
 
The signal on the sidechain, controlls 'How Much Compression' is applied.
 
The HP filter on the sidechain input, therefore affects the range of frequencies that are being used to dynamically control the amount of compression (the amount that the entire signal is compressed at that point in time).
 
scook has supplied the absolute correct answer above - very succinctly.
Perfect description in two sentences.
 
Ignore the rest below that, it's incorrect, very confusing and misleading.
 
Cheers - Cliff
2013/11/25 20:00:44
jb101
cliffr
Sorry , much of the information in the above post is very inaccurate and I imagine would only confuse you.
 
For example, thsi control has no affect on what range of frequencies get compressed at all.
The whole input signal is always compressed - the entire frequency range.
Meaning that when compression is applied, it affects the entire signal.
 
The signal on the sidechain, controlls 'How Much Compression' is applied.
 
The HP filter on the sidechain input, therefore affects the range of frequencies that are being used to dynamically control the amount of compression (the amount that the entire signal is compressed at that point in time).
 
scook has supplied the absolute correct answer above - very succinctly.
Perfect description in two sentences.
 
Ignore the rest below that, it's incorrect, very confusing and misleading.
 
Cheers - Cliff




What Scook and Cliffr said.
2013/11/28 00:54:42
aglewis723
I understand FULLY!  Thank you everyone for helping me out, right or wrong!  :)
 
 
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