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#346197 - 04/07/2011 17:43 4-channel EQ uses the wrong Q
presslab
journeyman

Registered: 29/07/2008
Posts: 73
Loc: North Bay, CA
I noticed when changing from 2-channel to 4-channel EQ I could not get the same sound. After playing with it for a bit I realized that the 4-channel EQ uses the same Q values as the 2-channel. This is wrong, because the 4-channel has only half the bands and therefore the Q should be half as well. This would allow each pass band to cover the frequency range up to the next pass band.

This could be fudged in Hijack to divide the Q for each band in half when in 4-channel mode. Or it is possible in the player to force a Q, but it resets whenever the gain is changed.

I thought I would mention this in case anyone notices strange behavior like I have.

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#346284 - 07/07/2011 20:18 Re: 4-channel EQ uses the wrong Q [Re: presslab]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 30578
Loc: Seattle, WA
I can't believe with all the messing about that I did with the EQ's that I never grokked this. I understand that stuff, too.

One of the things I wanted to do was to use 4-channel mode like a crossover. And it never quite worked. I never understood why until now.

Wow.
_________________________
Tony Fabris

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#346291 - 07/07/2011 21:51 Re: 4-channel EQ uses the wrong Q [Re: tfabris]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7853
Loc: Seattle, WA
*revokes Tony's beta card* smile
_________________________
Tom

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#346295 - 07/07/2011 23:35 Re: 4-channel EQ uses the wrong Q [Re: tfabris]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 13498
Loc: Canada
Perhaps one of the ex-empeg guys (Peter perhaps?) might provide sufficient hints for use to patch the player executable.. ?

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#346313 - 08/07/2011 17:37 Re: 4-channel EQ uses the wrong Q [Re: mlord]
peter
carpal tunnel

Registered: 13/07/2000
Posts: 4140
Loc: Cambridge, England
Ucch, not this time -- I don't have a clue. Can't you just use parametric mode, or was that only in the v3 alphas?

Peter

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#346315 - 08/07/2011 19:09 Re: 4-channel EQ uses the wrong Q [Re: peter]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 30578
Loc: Seattle, WA
I thought he was saying that he couldn't adjust the Q values properly for the 4-channel mode.
_________________________
Tony Fabris

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#346317 - 08/07/2011 23:34 Re: 4-channel EQ uses the wrong Q [Re: tfabris]
presslab
journeyman

Registered: 29/07/2008
Posts: 73
Loc: North Bay, CA
Yes I am using the 4-channel parametric EQ.

Well, it is possible to manually enter the Q value into the player. But whenever you change the gain for that band, the Q value is reset to an incorrectly calculated value. This makes it very frustrating to set up the EQ as every time the gain is changed the Q needs to be changed as well.

The Q is also a calculated number, depending on how much gain that band has. I suspect the same calculation is done for 2-channel or 4-channel so patching the binary will make one work correctly, or the other, but not both.

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