--- In [email protected], "rhblumeng" <[EMAIL PROTECTED]> wrote: > > We all assume that the better sound of the SDR is due to the dsp > filters, and the overwhelming portion may just be that. > > BUT, if one can "see" the improvement we all know is there in going > from an envelope type detector to a better type, could we not also > use this technology to "see" subtle differences in the > various "better" detectors (sync and others) and whether there is an > even cleaner sound to be had from improved detector algorithms? > > It can be easy when something makes a great deal of improvement, to > get caught up in celebration, and ignore other lesser, but perhaps > valuable opportunities. > > I am just trying to ascertain whether more experimentation with > detector algorithms could be fruitful... > > My best to you, Bob > Bob,
ultimately, you, Claudio and myself all three agree on the same things.... there are some changes, like using a given demodulator algorithm instead of another, whose effects can and must be measured. A lower degree of harmonic distortion is quite measurable and it is well known that it results in a more pleasant listening. What I just wanted to point out is that not everything is measurable... you can measure the group delay of a crystal filter, but in this case its effect is not so automatically stated. Different group delays are perceived differently by different persons... there is a theory that says that the human ears are not sensitive to the relative phase between the various harmonics of a given sound, and this has its roots on the working of the ear. But tests performed by the audiophiles revealed that a few persons as a matter of fact are "phase deaf", while others are quite sensitive to it... so measuring the group delay of a filter tells you nothing about how a given person will judge the quality of that audio... as much as we all would like to eliminate the subjective judgment from any objective measurement, there are nevertheless things that escape a rigorous and instrumental analysis... 73 Alberto I2PHD
