Originally Posted by Bob Pariseau
^ The OPPO players attenuate the SACD LFE channel by -10dB so that the same Sub level you set up for other content will also work when playing SACD content.
Thus the external boost is still used: +10dB if no Crossover happening, +15dB if a Crossover engaged.
This is true even when using SACD Output DSD to the Analog outputs, and also with SACD Output PCM on both Analog and HDMI.
If sending HDMI DSD to your AVR, then there can be no such helpful adjustment, so what happens is up to what your AVR does with HDMI DSD input.
As always with SACD, it is wise to test levels, including the LFE level, with a calibration track recorded as DSD, such as that PentaTone SACD, just to be sure you are hearing exactly what your setup is doing with actual DSD recordings.
That makes sense Bob, and fits with how I have my system set up for SACD and previously posted here.
It is at odds with how my previous player, the Arcam FMJ DV139 used to handle DSD - SACD encoding had no 10db attenuation so the 7.1 analogue bass channel input on the "matching" Arcam receiver played too quiet for SACD if setup correctly for DVD-Audio.
It still remains that on SACD, the ".1" channel is not an LFE channel but a full range channel capable of containing sound at any frequency.
How you handle bass in your system means with some discs you can simply discard the sub channel and lose nothing, (and probably the majority of SACD are 5.0 anyway).
The Scarlett book specification was not well thought out or written with regards to didactic bass handling for mastering, authoring or playback, so a lot of variation exists. Hence, different SACD's vary unfortunately.
-Some discs use a crossover filter for the 5 channels using a 120 Hz maximum frequency and DUPLICATE the "LFE" frequencies into the subwoofer channel. (Dolly Parton's Little Sparrow multichannel layer is unlistenable due to the extreme bass unless you turn off the sub, or do as I did which is to convert DSD to 5.1 flac and cut the subwoofer channel completely. At this point, the frequency plot spectrum in Audyssey of all channels combined becomes near identical to the stereo mix which confirms to me that it is duplicated bass)
-Some discs use a crossover filter for the 5 channels using a 120 Hz maximum frequency and EXTRACT "LFE" bass into the subwoofer channel, just as they would for DVD and Blu-ray.
-Some discs use a different crossover such as 80 Hz to EXTRACT bass into an "LFE" channel. The lack of a sub is less of a problem with these discs than with a 120 Hz filter.
-Some discs attenuate the subwoofer channel on the SACD by 10dB as would be done for LFE on a DVD / Blu-ray
-Some discs present the subwoofer channel non attenuated as per Scarlett Book
Hence, as much as I seem to prefer DSD when I trial it, I can see that there is no such thing as a universally correct DSD Direct because you cannot guarantee that the sound you hear is as the artist / engineer etc intended because much of the time, due to a "vague" specification open to interpretation, their intentions regarding how to engineer/ master / author a SACD got lost or jumbled and it can be anybody's guess how the bass is presented on the disc if there is any content in the .1 channel.