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The formula for the 100dB stroke fader?

Posted: 09 Jan 2012 22:16
by jjlemur
Hi guys,

I am making a remote control surface for a digital mixing software.
I want to put "monitor"s for mixing faders' positions in dB as the real console shows, but I don't know what formula I can plug in.

I think it's some sort of Log function but I can not figure out or find the resources.
The fader is -90dB(infinite) to +10dB.

Also, if anybody knows how to make a formula for the panpot(bipolar), which shows L100 -0- R100. I don't need L/R but at least want to have it show 100 -0- 100.

Thank you so much.

JJ

Re: The formula for the 100dB stroke fader?

Posted: 11 Jan 2012 02:01
by Phil999
for the volume fader I don't know, but the panner is easy:

-100+Pan.x*200

Re: The formula for the 100dB stroke fader?

Posted: 11 Jan 2012 02:49
by Macciza
Hi
This thread should cover what you need . . .
http://liine.net/forum/viewtopic.php?f= ... 1698#p1698

Cheers
MM

Re: The formula for the 100dB stroke fader?

Posted: 11 Jan 2012 05:00
by jjlemur
Wow, amazing! Thanks MM.

20*(log(x*127/108))*6/3.241 is great.

But I am wondering if this can be slightly altered so it shows from inf.(-90dB) to +10dB.
Do you know? I tried some, but never reached the correct one...

Thanks!

JJ

Re: The formula for the 100dB stroke fader?

Posted: 11 Jan 2012 17:47
by jjlemur
Hey Phil999,

Thanks to you too! I needed to know that. It looks great.
But do you know if it can be 100 to the both side L/R? Not like -100 -0- 100?

Or I wonder if we can put texts before those values, like "L"100 and "R"100

Thanks so much!

JJ

Re: The formula for the 100dB stroke fader?

Posted: 11 Jan 2012 18:02
by Phil999
jjlemur wrote: But do you know if it can be 100 to the both side L/R? Not like -100 -0- 100?
I'm sure it can be done, but I don't know yet how to express it. You need to multiply with -1 if the value is negative.

Re: The formula for the 100dB stroke fader?

Posted: 12 Jan 2012 01:10
by Macciza
Phil999 wrote: You need to multiply with -1 if the value is negative.
Or use abs() - to give you the unsigned version on the number

MM

Re: The formula for the 100dB stroke fader?

Posted: 12 Jan 2012 13:27
by Phil999
yes! That's it.

Re: The formula for the 100dB stroke fader?

Posted: 13 Jan 2012 20:04
by jjlemur
Thanks guys!

I tried "()", but it doesn't change anything. Still I have -100 at Right side.

I put like "(100-pan.x*200)" in the item of "value=".

Am I doing something wrong way or misunderstood?

I really appreciate your help!

JJ

Re: The formula for the 100dB stroke fader?

Posted: 14 Jan 2012 00:16
by Phil999
jjlemur wrote: I put like "(100-pan.x*200)" in the item of "value=".
It must start with -100, so that it will display 0 in the center position when multiplied with 200.

-100+pan.x*200

to get absolute values (values >=0), write

abs(-100+pan.x*200)