Do all Mediatek-based BDPs have bass management anomalies?

^ Since there are differences between the Oppo 93/95 and the Oppo 83 (e.g., in what happens to LFE when you set the Subwoofer to OFF), it's evident that his "all Oppo" players comment is, umm, not sufficiently thought out.

It also looks like he's got some basic facts wrong. The Analog Subwoofer output of the Oppo 93/95 for example is a fixed -15dB down from the Analog main speaker channels regardless whether those speakers are all set to Large or not. The first -10dB of that comes from the standard encoding of LFE. The additional -5dB allows headroom in case any of the speakers are set to Small. The fundamental document from Dolby Labs (circa 2000) defining how to do this stuff includes this as an approved method. The necessary +15dB boost should be applied external to the player. You can of course simply raise the volume knob on the sub. But typically an AVR will provide +10dB of that by default, and several AVRs offer the full +15dB as an option.

I've heard zero complaints against the Oppo players for the other problems he alludes to, and there are *LOTS* of people using the player's bass management in, for example, the Oppo 95 who are posting in its thread. He may indeed have found a bug, but I'd be very surprised if a bug like that was missed by all the enthusiasts in the 95 thread.
--Bob

Not really. There's more than one "approved" way of doing this. The choice is between having a fixed attenuation -- regardless of whether any speakers are set to Small, or changing the attenuation based on whether any speakers are set to Small. Both methods are spelled out in the defining document from Dolby Las that I alluded to.

Oppo feels the fixed attenuation approach is less confusing for users if they play with Large/Small settings. There's also the issue of users who want to use DSD-Direct-to-Analog conversion for SACD playback, since when that is engaged, no bass steering can happen (no audio processing of ANY sort can happen), so any speakers set to Small get treated as Large. To have the sub output change attenuation then as well is a recipe for user confusion.
--Bob