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High Pass Filter. How do you use it?
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mubali
Mubali
Started Topics :
71
Posts :
2219
Posted : Jan 10, 2008 05:17
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I stand corrected... ok.
  An Eagle may soar, but Weasels don't get sucked into jet engines. |
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Trip-
IsraTrance Team
Started Topics :
101
Posts :
3239
Posted : Jan 10, 2008 10:00
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Colin,
how is it possible that a low frequency component creates cancelations with a high frequency one...?
  Crackling universes dive into their own neverending crackle...
AgalactiA |
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makus
Overdream
Started Topics :
82
Posts :
3087
Posted : Jan 10, 2008 21:33
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MadScientist
IsraTrance Full Member
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97
Posts :
1220
Posted : Jan 10, 2008 22:13
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he said there is...and that when the frequency that cancels the other one out gets cutted, the cancellation disappears
  https://soundcloud.com/hazak
"Have you ever had that feeling where you're not sure if you're awake or still dreaming?"
"Hmm, yeah... All the time, man - it's called mescaline. The only way to fly!" |
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psylevation
IsraTrance Full Member
Started Topics :
52
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841
Posted : Jan 11, 2008 00:36
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I'll check out the GRM tools one, Thanx.
  ~Airyck~
~Unoccupied Mind ~
Psyowa! |
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UnderTow
Started Topics :
9
Posts :
1448
Posted : Jan 11, 2008 02:36
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The law of conservation of energy? LOL!
Anyway, about cancellation:
Imagine that a high frequency peaks exactly when a low frequency has a dip in the wave cycle, the peak in the higher frequency will be lower. Now remove the low frequency, the peak in the high frequency will be higher.
When you hi pass a complex mix of frequencies (exactly what music is) there is bound to be a peak somewhere that coincides with a a dip in the low frequencies thus the peak will be higher.
Here is a quick graphical example:
This is a 20Hz sine + a 1000Hz sine and a short 200Hz burst: http://www.puretone.nl/Cancelation_1.png
The 200Hz burst doesn't peak very high.
High pass the sound so that the 20Hz is removed and you get this:
http://www.puretone.nl/Cancelation_2.png
Now the 200Hz burst peaks much higher.
It is all quite simple. No need to involve thermodynamics.
Mubali, I think you might be referring to the way we perceive sound. When you remove low frequencies, sounds seem to become brighter and vice versa. This is purely a psychoacoustic effect and has nothing to do with the actual energy levels in the sound.
UnderTow |
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dija
IsraTrance Junior Member
Started Topics :
48
Posts :
483
Posted : Jan 11, 2008 10:55
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High pass filtering is necessary for nearly all instruments. If you have some really fat pads but they conflict with the bass then you need to move the highpass filter above the root bass frequencies. If you want fat fat sounds you must use less sounds. When composing you should be thinking of each instrument as a note in the chord. Playing in the proper octaves is part of the key. I've found that over using eq can be my worst enemy especially when it comes to boosting. Although, I may use boost to bring out a certain characteristic of a sound I want to stand out more. However, higher frequencies take a lot less power to be audible. If you have 3 instruments playing and each has some unnecessary low end its going to stack on one another and become a significant burden on the cleanliness of the track. As it was stated using too much high pass makes your sounds thin. As another person said also I turn the high pass up until it affects the sound in a way that is not desirable then I turn the high pass back down to remove the low frequencies that was not part of what I want. If I really like the instrument and want to try to fit it in I try to use notching so that it keeps some of its low end but still allows the bass and kick to come through it. Also a high pass filter that leaves some of the low end fatness of your sound can work in addition to a shelf that reduces the level of the low frequencies. That way you get to keep some of the original fatness. Its all about balance, arrangement, and compromises. Depending on the track I sometimes do quite a lot of very tiny notches by looking at dominant frequencies of other instruments. Say I have pads that span a wide frequency range. Very tiny notches can be made in the pads that does not affect the sound very much if at all and it will bring out the dominant frequencies of some of the other instruments you wish to fit in. Theres always side chaining as well.
I dunno if I helped anybody. Some much more knowledgeable people have posted above me so please feel free to correct me if any of my thoughts are incorrect. |
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