I have another issue to raise about LFE content production (not having to do with bass management per se). It's something I've seen in e.g. 5.1 music mixes that exist in Dolby/DTS lossy format and also in some PCM format (like offered on BluRay, or DVD-A). Possibly this issue deserves a separate thread so as not to dilute this one
To wit:
DTS and DD LFE contents are, by spec, steeply rolled off above some low frequency (iiirc 120 Hz?). This is quite apparent in frequency/amplitude plots of LFE channels. In addition, typical AVRs these days have an 'LFE LPF' setting, so users can set the low pass filtering of the LFE output there. On top of that there is typically a filter/crossover setting on the subwoofer itself (sometimes user-defeatable, but always user-adjustable). But the rolloff enforced on the DD/DTS version itself means that at most , the user could allow LFE content bandwidth only up to ~120 Hz to emit from the sub.
HOWEVER: PCM LFE of the same mix, released on BluRay (or perhaps DVDA...or even perhaps DSD, though I forget whether I've seen it there) sometimes shows full range signal in the LFE channel (as seen in freq/amp plots of the LFE channel contents). E/g, a full range bass guitar and/or drum part has been mixed to LFE, but has not been rolled off.
The effect of this (aside from making it super easy for musicians to learn bass and drum parts!), is that the producer of the BluRay version is depending on the listener's system to apply some low pass filtering. Without proper filtering, the subwoofer could easily become localizable. (Also , bass/drum content may even be *duplicated* on other channels, resulting in other issues...), and certainly they are not hearing what was 'intended'.
I could provide screen capture examples of this, if need be.