Originally Posted by pepar
Is this a feature or a bug? If the former, how?
When Crossover is engaged additional "steered bass" from the main speaker channels is summed with the LFE content going out on the Subwoofer Analog output.
LFE content is recorded -10dB down so that there is headroom for recording *LOUD* bass without risk of clipping the preamp input that receives the signal. This means that +10dB of Sub Boost needs to be applied external to the player so that the Sub content (LFE in this case) is matched in level with the main speakers content. Typically AVRs do this, but if necessary it can also be done by raising the volume knob on the Sub itself to achieve the proper level.
But with Crossover engaged, additional headroom is needed so that the combo of LFE and steered bass still does not have the potential of clipping the preamp's input. So an additional -5dB of attenuation is applied. This means that when Crossover is engaged the required Sub Boost -- still external to the player -- is +15dB.