Re: perfect downmix for SpecWeb; No, SpecWeb doesn't have the constraint that it must mix back down to the exact stereo mix, however we don't add anything (with the exception of a non-default setting that lets you add more extracted ambiance back in).
You could set things so it does that, but since you have control of widths to place certain sounds in certain speakers if you mixed that down to stereo it wouldn't 100% match the original.
I guess, however, you could argue that when a producer does a 5.1 re-mix of a classic, there is no expectation that it mix down 100% to the original stereo from back in the day. The reason Penteo 16 and some other have that constraint is for surround broadcasting, and for those that listen to that in stereo, which is not what we are doing here. It's more like the 5.1 re-mixer, we are making something new, a 5.1 version of a song that we enjoy hearing in 5.1.
However, looking at the waveforms Jon posted, it doesn't seem that channel level adjustments are what he sees as missing in the Penteo 16 results. All channels of the Penteo 16 wave forms look similar, except for volume. So even if you adjusted the channel volumes, it wouldn't result in waveforms that look like the SpecWeb output that show different shaped waveforms across the different channels.
Re: why -m4 (undocumented development test of "Zone 2", a different way of distributing sounds to speakers after ArcTan determines the perceived angle of the sound in the Stereo) is not the default in 2.0b1 (which I noticed yesterday actually makes short cuts on your desktop that say 2.0a2
) That's one of two reasons why this version is a beta.
I need user feed back on if -m4 is "better" than the default (-m1 "Across" "Constant Power Panning") and if so is it consistently "better", so that it
should be the new default going forward.
FYI the other reason is two of the width settings in this version.
From the ini file:
;centerwidth is the amount of the sound field to put in the center speaker
;0 would be no center at all and 119 (the maximum value) would be
;a big chunk of the common sound between left and right
;default 54 (SpecWeb 1.5 default was: 75)
centerwidth=54
;
;frontwidth is the amount of the sound field to put in the front speakers
;0 would be no fronts at all and 120 (the maximum value) would be
;a big chunk of the sound field goes to the fronts
;default 36 (SpecWeb 1.5 default was: 90)
;Note that there is no "rearwidth" because the rears get whatever is left
;over after you specify the center and front widths.
;adjusting the widths is one way to reduce artifacts
frontwidth=36
The new values, 54 and 36, were arrived at after a statistical analysis of 38 songs I have gathered, form across musical types and producers, to be used both as "torture"/regression tests in any changes to SpecWeb, and to be used as objective listening examples for changes.
However, the few alpha testers I have left gave feedback that they preferred the original settings (which derived from DKA suggested
starting points for the original Spec in Plogue Bidule).
So, again, I need feedback from users on what the default centerwidth and frontwidth values should be. Values that work for most/typical songs.
Then I would release 2.0 (or 2.1 if there are bugs/features updates) with those defaults.