Keep in mind that an SACD is going to not use the digital bass management - I'd look first at the player's settings and second at the position of the bass management switch on the back of the 950. Is the loss of sub signal appearing just on SACD or DVD-Audio discs, or is it across the board? Also, have you tried the 950's test tones to see if there's a problem with the level there (which might indicate a problem with the sub if the setup had been working previously)?