Page 1 of 1

Fader.x to dB Scaling Issue...

Posted: 07 Jun 2013 15:32
by Lewb
I've been going through the advice given on the forums about how to deal with this issue, and I've got some nice approximations.

However, I've hit a stumbling block.

The Midi Documentation for my Roland M-400 Mixer includes a lovely table giving the exact db values for each of the 128 steps.
I'm assuming that I could just enter these as a vector map. But I'm concerned about turning the 0.000 to 1.000 accurately into the exact steps.

Can i really just use?

Code: Select all

Fader.x*127
Thanks...

Re: Fader.x to dB Scaling Issue...

Posted: 07 Jun 2013 19:28
by Softcore
If you really know the values for all 128 steps create a global expression name it val (just an example) and then type in the steps values

for example:

val={-99, -98, -97........-0.1, 0}

Then you just have to display in a monitor for example

Monitor.value = val[Fader.x*127]

Re: Fader.x to dB Scaling Issue...

Posted: 07 Jun 2013 19:34
by Lewb
Looks like i've got some typing to do then!

Here's hoping its good! I've gotten so fed up trying to find a good and reliable wireless solution for this desk. I've tried TouchOSC, Stereokraut and MidiDesigner and nothing's had the flexibility to make it work.

Re: Fader.x to dB Scaling Issue...

Posted: 07 Jun 2013 20:33
by Lewb
Hmm, it didn't work.

I'm not sure the scale on the fader translated back into 128 steps...

Any thoughts?

Re: Fader.x to dB Scaling Issue...

Posted: 07 Jun 2013 21:19
by Softcore
Excuse me, Im not sure what you are trying to achieve here.....I was describing a method of displaying dB accurate values inside Lemur. What ARE you trying to do?

Re: Fader.x to dB Scaling Issue...

Posted: 08 Jun 2013 09:17
by Lewb
That's what I'm trying to do, only it's not lining up accurately.

Faders output a value between 0 and 1, I'm trying to get them to output 0 to 127.

I know that Fader.x*127 does this, but it doesn't appear to line up in the positions it should when monitoring the sent midi commands and the faders on the target console...

Re: Fader.x to dB Scaling Issue...

Posted: 08 Jun 2013 09:54
by Softcore
Still dont understand wht you mean "output" 0 to 127.....

Because......by default x gets a range of 0 to 127 when it goes "out" of Lemur as midi.......

If we are talking visual representation inside Lemur Fader.x*127 gives you a range of 0 to 127......

But of course, volume faders are not linear....Meaning, around halfway of its position, the dB value is not the half of the whole range....And thats where the val vector I posted above comes into play....BUT you need to have many (not necessary all) values inside that vector and then instruct Lemur to convert the x range to that vector range....

try for example this

val = {-100, -80, 0, 6}

Monitor.value = val[Fader.x*3]

to see what I mean.....

Do notice that inside the brackets, we multiply Fader.x by sizeof(val) - 1

All the above are related to "presenting" dB values (and taking under consideration their non-linearity) inside Lemur.....If waht you are asking is an actual non-linear fader outputing non-linear values (which I really doubt) then you need another approach.

Re: Fader.x to dB Scaling Issue...

Posted: 08 Jun 2013 10:00
by Softcore
heres an example of the above....Again, ideally you would need all 127 possible dB values for a volume fader to have a mathematically precise "read out"....I have mocked up a few faders in the past for Ableton Live found in the modules section, using the same principle but of course not with 127 values