Ouch, the steep (-s) conversion clipped and that's why the noise floor was elevated. After fixing that, the noise floor is now comparable to the non-steep version (and the same applies if you use it together with -v or -u):
I may be wrong... but "-s" isnt a quality setting... so without a quality setting specified your quality will default to "-h" (and the related combo settings it drags in, as per my original post above)
"-s" relates to Bandwidth (Audio Passband Percentage):
-s = -3 dB 99% (steep filter)
-b <74 .. 99.7> = -3 dB percentage
-B <53 .. 99.5> = 0 dB percentage
I would imagine you need to use a quality setting and "-s" in combo?. I theory "-u -s" gets you the good stuff from "-u" (as per my original post above) plus a steeper filter.
Maybe play around with that?
Also in theory "-b 99.7" is an even steeper passband!!!
Peter