Re: [LAD] Floating point Denormals: C++ and Waf

[Harry van Haaren] Some useful numeric suggestions have already been made, and the why amounts to this: http://en.wikipedia.org/wiki/Single-precision_floating-point_format : """The minimum positive normal value [of a 32-bit float] is 2−126 ≈ 1.18 × 10−38""" 1.0f corresponding to 0dB makes 1.18e-38 equivalent to around -758dB. Roughly speaking, 16 bit samples cover around 90 dB (1./(1<<15)), 24 bits give you 138 dB (1./(1<<23)). For all intents and purposes involving current digital audio hardware and human beings at their current point of hearing evolution, anything past that is surely perfectly inaudible, so a sensible approach is to choose any amplitude between this and the above mentioned smallest normal float for your injected "normalising" signal, keeping in mind subsequent amplification factors in your signal path, and that amplitudes can decrease quickly in IIR filters, especially when you stack them (one feeding the next). Tim