cliveb wrote: > eCo Wrote: > >>Pat...normalization is apparently not the same in this software. I've >>been assured there is no expansion or compression when it is used. > > I am 99.99999% certain that Pat has not suggested that normalisation > will involve compression. He understands fully what the implications > are. The simple fact of the matter is that if you try to apply a linear > amplitude adjustment to a digital recording, then unless the adjustment > factor is an exact power of 2, you *will* incur some degree of rounding > error. This is nothing to do with compression: it is in principle > *impossible* for any software to perform normalisation that avoids > rounding errors. > > That said, let's be pragmatic about the issue. The audibility of the > rounding errors that are introduced by normalisation is vanishingly > small compared to the much grosser effect of actually changing the > volume. I have over a decade of experience in digitising LPs, and I > would be very surprised to hear that anyone was able to successfully > ABX normalised v. unnormalised recordings of an LP (after level > matching, of course). Nobody should lose sleep over it: in practice, > normalisation is a benign operation.
Pat is right. Normalisation involves scaling the values that represent the waveform by a simple process of multiplication. I think the confusion has arisen because eCO said: "Normalizing in my software simply adds a nominal gain throughout the recording" That is also true, if eCO is tlaking about the addition of a dB value. dB use logarithmic scale, relative to a reference value, e.g.: dB = 20 log10(V/V0), where V0 is the reference value. The additional of a "nominal gain" in dB is equivalent the multiplying the actual voltage values by a constant. Now, the waveform is AC, i.e. there are +ve and -ve values as well as some 0 values; so, multiplying by a constant has the effect of stretching the waveform about the zero axis. Here's a simple example: Input: 4 2 0 -2 -4 Gain: 2 Output: 8 4 0 -4 -8 HTH, R. _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
