Originally Posted by pbarach
Subwoofer output for SACDs reduced by 10 dB when sending DSD
Other than sending SACD signals only as PCM to the AVR or upping the subwoofer trim by 10 dB in the AVR, is there any other workaround for the fact that the subwoofer channel is 10 dB too low when SACD output goes to the AVR as a DSD signal?
If you are talking about HDMI DSD output, the OPPO does nothing to the Sub channel level for that. It is treated like a Bitstream. No settings in the OPPO will alter that. I.e., it is an AVR issue for how that HDMI DSD input is being handled by the AVR.
One way to double-check just how the signal is being handled is with tracks 43-48 of the 5.1 layer of, "Stay in Tune with PentaTone", SACD. (Do *NOT* use the Sub channel ID track, which looks identical but isn't, found earlier on that disc.)
Be aware that there is no consistency in how the Sub channel is used in 5.1 SACD recordings. What Sony intended was that the .1 channel be recorded at the same level as the other speaker channels, in contrast to the normal usage by all OTHER formats where the .1 channel is recorded -10dB down so as to provide a special channel in which to mix *LOUD* bass. This design screw up has led many studios to avoid using that channel altogether for their SACD discs. I.e., their 5.1 discs have the .1 channel silent and ALL bass is mixed into the normal speaker channels. You only get output on the Sub if you engage Crossover processing.
But some other studios have over-thought the problem and actually sell SACD discs with the .1 channel recorded -10dB down on disc, "to be helpful"! If you play one of those discs, then you'll need to add an extra +10dB sub boost to square things, AND you can't use Crossover processing because there's no way for the player to know the .1 content is not starting off at the level it is supposed to be -- so it is out of balanced with the bass mixed in from the other channels. Of course to get Crossover processing in the player (for the multi-channel Analog outputs), you need to let it convert the DSD to LPCM
If you let the player convert the DSD to LPCM -- either for HDMI LPCM output or for multi-channel Analog output -- the player will apply -10dB attenuation to the Sub output channel so that the same Sub boost (external to the player) you are applying with other multi-channel content can be used without change. Unless you are so unlucky as to have one of those bogus SACD discs with the .1 channel ALREADY recorded -10dB down.....