Forums > MaxMSP

BCR Pot curve adjust

July 3, 2008 | 12:14 am

Does anyone have a patch to adjust the pot curves output on my BCR?

Cheers.


July 3, 2008 | 1:23 am

it should just be a matter of using some kind of exponential function on the input values.. (as far as i know)


July 3, 2008 | 1:42 am

On Jul 2, 2008, at 5:14 PM, David Corrin wrote:
> Does anyone have a patch to adjust the pot curves output on my BCR?

Does the BCR have settable curves you are trying to set from Max, or
are you trying to modify the data in Max?

If the latter, you could either use some sort of math on it, or use a
table to look up new values, based on the existing pot values.

-C

Chris Muir
cbm@well.com

http://www.xfade.com


July 3, 2008 | 1:51 am

Here is a nice curve generator patch that was posted on the mailing list a long time ago. I’m sure you can use to to put something together.

– Pasted Max Patch, click to expand. –

July 3, 2008 | 1:59 am

Quote: Chris Muir wrote on Wed, 02 July 2008 21:42
—————————————————-
>
> Does the BCR have settable curves you are trying to set from Max, or
> are you trying to modify the data in Max?

i have a BCR, and as far as i know there is no such functionality.
however, there are some undocumented features, which can be used through sysex editing and such, but i’m not sure if they have anything to set curves


July 3, 2008 | 2:15 am

Wow you guys/girls are fast! and helpful.

I think you are more akin to programmers than musicians from your speedy replies and willingness to help.

I am fairly new to max and have only basic experience using objects.

Just how hard will will it be to implement that piece of code into a patch that actually performs how I would like?

For your interest I am trying to use a rotary encoder as a crossfader of sorts. I have mapped it to 2 seperate faders in ableton and inverted the range on one so when I dial it they go opposite ways. My problem is that being logarithmic and not linear I get a very attenuated crossfade in the middle of the ranges. Ideally I would like consistent volume.

Thanks for your help guys and girls.


July 3, 2008 | 3:26 am

Hmmmm just pondering on my lunch break….

I think I am a bit retarded.

If my faders are relying on inverted values from the same rotary encoder then no matter what the curve is it will still be the exact inverse value at any given point. The rate of movement will be affected by changing the curve but not the relative volume changes. derrrrrrr….

Somehow I need to adjust the individual fader curves before the bcr comes into play. Anyone know any code for converting a logarithmic function into a linear one.

This is proving quite the pickle.

Basically if a sine wave is playing on 2 channels I want to be able to use the rotary to cross fade between them without noticing a drop in volume.

Somehow I have a feeling that someone will know just what I want to do and have a much easier way to do it. And no, I cant use the cross fader as there is only 1 of them and I want one every 2 channels.

Dave.


July 3, 2008 | 3:32 am

look up crossfading in google or something, and try to find information about logarithmic crossfading. then try to apply whatever math is used to the midi control values.


July 3, 2008 | 3:46 am

On Jul 2, 2008, at 8:26 PM, David Corrin wrote:

> If my faders are relying on inverted values from the same rotary
> encoder then no matter what the curve is it will still be the exact
> inverse value at any given point.

Try something like this:

– Pasted Max Patch, click to expand. –

Chris Muir
cbm@well.com

http://www.xfade.com


July 3, 2008 | 9:16 am

You are the man!!!!!

Can you give me any tips on speeding my learning process with max?

I’d like to learn so I can be of help in the future to other noobs with silly ableton problems.

thanks again guys…

dave out.


July 3, 2008 | 9:47 am

There’s only one solution:
Just lookup and walk through all the toturials. Then you will gain all the
necessary knowledge…
J.

2008/7/3 David Corrin :

> Can you give me any tips on speeding my learning process with max?
> I’d like to learn so I can be of help in the future to other noobs with
> silly ableton problems.
>


July 3, 2008 | 10:21 am

The most flexible scale/curve objects are the lp.scampi family in Litter Power. If I do say so myself.

They’re in the Litter Starter Pack, located at the URI below. I’d give them a try.


July 3, 2008 | 10:34 am

The equal power curves are sinusoidal. You’re not going to get better than a rough approximation with any polynomial or exponential function.

I could add the equal-power curves to the lp.scampf family if there were a demand.

You can look up the equal power curves in any reference book (Roads, Moore, Dodge&Jerse, etc.). If you dig a bit Wikipedia should have them somewhere, too.


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