Unity Gain at 12 O'Clock

[S1User]

First let me thank the kind people here who always seem willing to help. I'm try to refamiliarize myself a bit with FS.

I have a knob that controls the output level of the sidechain input and i want it to be cetered at 12 O'Clock for unity gain. Turn right to add gain, turn left to trim. Ideally it would max out at +/- 12db. How do I do that? I've been trying with no luck so far. Thanks in advance

volume.png (32.23 KiB) Viewed 3452 times

[tulamide]

Use math! You're multiplying a number, so 1 is unchanged and therefore 0 dB.

The formula for dBFS is 20 * log10(abs(value))

That tells you, that for -12 dB to +12 dB, the range has to be 0.25 to 4 (a quarter to a quadruple). Since it is a logarithmic scale, I would use the actual dB values for the knob (-12 to 12) and calculate the number (that you use to multiply the stream) with the reverse formula 10^(dB * 0.05)

[Spogg]

Here’s a couple of modules to do it. The stream version is by Martin Vicanek.

[S1User]

Thank you Spogg. That was exactly what I needed.

[Spogg]

Just for completeness, here are 2 modules which convert from linear to dB, where a 1 input gives 0dB, 2 gives +6dB etc. So the linear input could be called a gain ratio maybe.
The stream versions may be useful in compressors for example.