MStereoProcessor psychoacoustic prefiltering for analyzer

[ZentralmassivSound]

Hi there,

I noticed that in MStereoProcessor, in the analyzer, it seems that bass frequencies can make the whole plot appear very narrow whereas the perception of the sound is to the contrary very wide due to high frequencies. It appears to me that a Fletcher-Munson weighting of frequencies (in other words psychoacoustic prefiltering) would make sense for such a plot. Or maybe kind of a slope control for frequency weighting.

Cheers, Thorsten

[MeldaProduction]

Hi Thorsten,

well, I just tried and just don't think it is true. Try MOscillator and set width to say 1-2 semitones, then sweep the spectrum with your headphones on. It is pretty much wide all the time and so is the spectrum view.

[ZentralmassivSound]

OK here is what I observed: I had a track playing consisting basically of a bass and some treble rich synth plucks. The perceived stereo-width was very wide due to the synth. The plot in MSP however showed a pretty narrow field. So I muted the bass, and then the plot changed drastically, the synth was mainly moving on the y=x and y=-x diagonals. On the other hand muting the synth and soloing the bass yielded basically a mono plot. When both playing together, the analyzer was obviously largely driven by the bass as the plot remained very narrow, whereas my ear told me that the music had a wide stereo field. So I think the bass with its high energy goes into the plot with much more weight than the treble, however the ear perceives the width largely from the treble, thus a mismatch between plot and perception.

[MeldaProduction]

I don't think that's true, it's more like psychoacoustical thing - in many cases stuff that appears to be very wide it's not wide at all according to the plot, because, well, it isn't. Imagine just an impulse, delayed by one sample in left channel. According to the plug it's going to be superwide, yet you won't perceieve that, it will just be weird . And it's a good example, because in a way this will be wide in higher frequencies, but not so much for low frequencies. But only for human ears .