Thank you, I know that in PURE mode, no DSP processing, therefore no redirection of bass to SW. Stereo in PURE mode : the SW sleeps (no signal).
But with DSD SACD, there is 5.1 chanels so .1 direct to the SW, even in PURE mode : the SW is alive, I can ear it ...
But lacking of a SACD reference test disc, the SW being switched "LFE", I don't know if the bass volume is correct (the amp does the correction as it does for DD or DTS) or is -10dB.
That is my question.
The subwoofer, the amplifier, and whether you're using pure mode or not are all irrelevant, it's entirely a function of the player's behaviour. Bear with me please while I try to explain.
Reference level on DVD is defined as: a full peak swing is 105dB, but 115dB on the LFE channel. To achieve the 115dB level, it is necessary to compress the LFE channel prior to mastering the DVD, and the 10dB LFE setting is used to expand the compressed signal. This is the LFE -10B you're aware of.
Since music doesn't have low frequency effects, the SACD standard has no architected
LFE channel, the -.1 is in essence a bass redirection, not a low frequency effects, channel, although architurally it's actually a full range channel. Multichannel SACDs either come in 5.0 or 5.1, where the 5.1 is essentially just the manufacturer applying bass redirection during mastering, and is mostly used in US sourced SACDs (e.g. Albany), with Europeans typically using 5.0, and as a result most classical SACDs are 5.0. The SACD standard clearly states that the .1 channel (if present) does
not need a +10dB boost, but as so often, things are not that simple in practice...
Most SACD players support bass redirection as part of the multichannel SACD replay thus supporting your subwoofer with 5.0 sources. However this is where things get messy. Many players, and most recent players, subsequently drop the level of the .1 channel prior to the analogue output so that the user can leave his A/V player consistently set at +10dB. Other players, especially earlier players, leave the .1 channel alone, meaning the user has to fiddle around with the +10dB setting when using the analogue inputs for both SACD and DVD-V. A few players have a setting to let you make up your own mind.
Summarizing therefore: what you have to do in your case is dependent on how your unidentified SACD player behaves. You will need to consult the player's manual to determine what it does or whether the behaviour can be configured.