That does seem odd, unless you are running 5.1 analog from the player to the receiver in which case (depending on brand) your receiver might be doing a straight pass-through and relying on the bass management in the player.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8