• Registered: 2013-01-12
  • Posts: 11

Topic: OSC dB to Decimal (and v.v.) conversion formula

I've implemented a Lemur interface to show gain reduction metering based on compression settings, but I need to know the formula to convert from Decimal messages sent to dB and vice-vers.a

I've done a basic exponential curve fit that's almost there but could use a little more accuracy.

  • Registered: 2013-01-12
  • Posts: 11

Re: OSC dB to Decimal (and v.v.) conversion formula

Ping?

  • Registered: 2016-01-05
  • Posts: 3

Re: OSC dB to Decimal (and v.v.) conversion formula

Digging this up because I'm trying to do the same!

In case this helps anyone who comes across this, the best I've come up with so far from the Fireface UCX master fader is:

OSC fader value f(x) - clamp to [0.0,1.0] with x in [-64,6] dB

     f(x) = a*exp(b*x)+c*exp(d*x) + e*x + f
Coefficients (with 95% confidence bounds):
       a =    -0.02432  (-0.03151, -0.01714)
       b =      0.2828  (0.2573, 0.3084)
       c =       0.383  (0.3781, 0.3879)
       d =     0.08446  (0.08209, 0.08683)
       e =    0.007062  (0.007006, 0.007119)
       f =      0.4546  (0.4509, 0.4583)

Goodness of fit:
  SSE: 0.0004117
  R-square: 1
  Adjusted R-square: 1
  RMSE: 0.001604

But an official answer would be great! smile