You can't get those 3 scenarios without making a settings change between them. For example the two sets of Dedicated Stereo Analog outputs -- the RCA pair and the XLR pair -- don't have separate settings.
Let's start with your #3
1) Wire Dedicated L/R RCA to the LF/RF multi-channel RCA input jacks of your Classe
2) Wire multi-channel C/LS/RS/LR/RR/Sub to the other multi-channel RCA input jacks of the 7.1 input set on your Classe
3) Set Stereo Signal to FRONT LEFT/RIGHT. This configures the Dedicated Stereo Analog outputs (both pairs) to respond to all the settings that would normally apply to LF/RF of the multi-channel output set.
4) In Speaker Configuration, set Down-mix to 7.1, and set all Speakers to LARGE with the Subwoofer ON.
In this configuration, the Subwoofer will need +10dB boost, external to the OPPO, to match the level of the other speaker RCA jacks. That boost may be provided automatically by the Classe as it passes the Subwoofer signal through to the Sub. If not, adjust it with the Volume knob on the Sub itself.
Check your levels using a calibration disc and a Sound Pressure Level (SPL) meter. I recommend the LPCM test tracks on AIX Audio Calibration, Blu-ray. The goal is to get all the channels, including the Sub to produce the same SPL. Typically you adjust main Volume to get 75dB SPL from LF, and then use trims to adjust the other channels to match as necessary. In the specific case of the Sub, use the Volume knob on the Sub itself to adjust instead of using its trim setting in the OPPO. As an added refinement, if you end up with any trims above 0dB, lower ALL of the trims (including Sub) the same amount so that all the trims are now either 0 or negative. Compensate by raising main Volume.
The result is that all of your normal speaker channels will be sent a Full Range signal. The Subwoofer will only be sent content in the LFE channel (the ".1" of 5.1 or 7.1). So when playing Stereo content (like a CD), which HAS no LFE channel, the Sub will be silent.
NOTE 1: I'm assuming you have no bass management enabled in the Classe itself, and that you are not routing your speaker signals through any other Crossover, such as in the Subwoofer. Indeed an Crossover in the Subwoofer itself should either be Disabled or should be cranked up to the highest possible frequency to get it out of the way as much as possible. It is important that bass management only be done in one place. And if you want your main speakers to be run Full Range, bass management should not be happening ANYWHERE. The settings above disable bass management (Crossover processing) in the OPPO.
NOTE 2: The Sub RCA output of the OPPO has to go through the Classe -- i.e., you can't wire it directly to the Subwoofer -- as otherwise its level won't respond to any volume changes you make in the Classe.
By the way, I don't recommend running speakers Full Range. It is a rare speaker that can produce bass AT VOLUME as well as a decent Subwoofer. Indeed, unless your normal speakers have powered woofers, odds are they can't really hit the deep bass notes at volume. I'm talking down to, say 15Hz.
If you decide to use a Crossover in the OPPO, I'd suggest trying a 60Hz setting. This rolls in over an octave (factor of 2 in frequency), so that the speakers are producing everything 60Hz and above, the Sub is producing everything 30Hz and below, and the Sub and speakers together share the load between 30 and 60Hz.
To employ a Crossover, set the normal speakers to SMALL (and Subwoofer still ON). With the Crossover enabled (i.e., when any speakers are set to SMALL), the Sub output will now need +15dB boost (not +10dB) external to the OPPO. The extra 5dB allows headroom so that LFE and steered bass can share the same output without clipping the input on your Classe. Again, use a calibration disc and an SPL meter. When you achieve 75dB SPL from all speaker and the Sub then you are done. The correct amount of sub boost is now baked in, whether that was provided entirely by Volume knob adjustment on the Sub, or by a mix of Volume on the Sub and Sub channel boost provided automatically by the Classe.
But back to your original #3
setup -- where all the normal speakers are Full Range.
Now what happens in your #1
setup --i.e., if you play Stereo content and use the XLR pair of the Dedicated Stereo outputs to a separate Stereo input pair on your Classe? Remember the RCA Dedicated pair and the other 5.1 channels of the OPPO's multi-channel output are still connected to the 7.1 multi-channel input of your Classe?
First of all, check that your Classe is OK having both RCA and XLR inputs connected simultaneously. Some pre-amps are not, even if you are not trying to mix RCA and XLR connections into a single listening setup.
That aside, the XLR outputs of the OPPO will work identically to the RCA Dedicated Stereo outputs -- except that just by the way XLR works, the XLR outs are +6dB hotter.
That means that Crossover processing, volume trims, and speaker distance adjustments all get applied to the Dedicated XLR outputs the same way they are applied to the Dedicated RCA outputs -- and again, this stuff gets applied *BECAUSE* we set Stereo Signal = FRONT LEFT/RIGHT above in the #3
But in the #3
setup we disable Crossover processing (setting all Speakers to LARGE). So as long as you are OK with the Volume Trims and Speaker Distances applying to the Dedicated XLR outs the same way they apply to the Dedicated RCA outs, you are good to go.
Note that in this #1
setup the Subwoofer output of the OPPO multi-channel set will be *SILENT*. You are playing STEREO content -- no LFE channel -- and you have LF/RF set to LARGE as part of the #3
setup, so no steered bass goes to that output either. Of course when you select the XLR stereo input of the Classe to listen to, you wouldn't hear anything on that RCA Sub output of the OPPO anyway.
So what happens in this #1
configuration if you play multi-channel content? The answer is that only the LF/RF channel content will make it out the Dedicated XLR L/R pair. By setting Stereo Signal to FRONT LEFT/RIGHT you've disable automatic down-mixing. Instead the Speaker Configuration > Down-Mix setting now applies and it is set to 7.1 -- i.e., no down-mixing at all. So if you play a 7.1 track in this #1
configuration, the C/LS/RS/LR/RR/LFE channels will all be discarded. The LF/RF channels will be played Full Range out the Dedicated XLR L/R pair.
That leaves your #2
configuration. A 2.1 channel output intending to use the Dedicated RCA L/R pair.
The easiest way to get that is to start with your #3
configuration (above). I.e., you are going to play into the MULTI-CHANNEL input of the Classe -- but with the C/LS/RS/LR/RR channels silent. Only the Dedicated L/R and the Sub will have sound.
To achieve that, you need to make two settings changes. First, you have to go into Speaker Configuration and switch LF/RF from LARGE to SMALL. (Whatever Crossover frequency you have set will now apply to those). Second, you need to go into the Sub and raise its Volume Trim 5dB higher. When any speakers are SMALL the Sub needs +15dB volume boost, and in configuration #3
above we set things up for +10dB boost.
Now ideally this additional +5dB Sub boost would be done external to the player. If there's any easy way to get the Classe to do that, for example, then do it there instead.
NOW when you play Stereo content -- which again, has no LFE channel -- the Dedicate Stereo Analog outs (both the RCA and XLR pair) will have Crossover processing engaged. Bass in those channels will be steered to the Sub RCA output of the OPPO's multi-channel set.
In the Classe, you select to listen to its multi-channel Input.
Note that you do not have to make a change to the Speaker Configuration > Down-Mix setting nor to the Stereo Signal setting. You have 7.1 Down-mix set in configuration #3
, and since you are playing content with fewer channels (Stereo) no down-mixing happens.
Now suppose you take my advice and change your #3
configuration to NOT send Full Range to the normal speakers?
To do that, you would modify configuration #3
so that all the speakers are set to SMALL (and Sub ON) with an appropriately choose Crossover frequency. I would suggest you go no lower than 60Hz for Crossover. Let the Sub handle everything 30Hz and below.
As stated above, when you set up this modified #3
, you will need +15dB of Sub boost, external to the player, for example by adjusting the Sub's own Volume knob. Again, you confirm you have this correct using a calibration disc and an SPL meter.
Once set this way, multi-channel content will send both LFE and steered bass from your SMALL speakers out the RCA Subwoofer output of the multi-channel set. They will be in balance with each other, and once the required +15dB boost is applied to that Sub signal they will also be in balance with the rest of the RCA outputs of the multi-channel set.
And as with the original #3
configuration, the LF/RF channels will actually be wired from the Dedicated Stereo Analog RCA L/R jacks.
But what happens if you now play STEREO content? Well, without making any changes you get a 2.1 output! The Dedicated L/R jacks and the Sub output will feed into the multi-channel input of the Classe. The other channels of the multi-channel set will be silent. And the SAME +15dB boost for the Sub you already had set up will still be CORRECT!
You don't have to change anything. You leave Speaker Configuration > Down-mix at 7.1. You leave Stereo Signal at FRONT LEFT/RIGHT. You leave all the volume trims and the sub boost as already set. And you can switch between multichannel and stereo content at will.
So that gets you configuration #2
and a modified (with Crossover) configuration #3
without having to make any settings changes -- both playing into the multi-channel input of your Classe.
OK, so what about configuration #1
? That's 2.0 output via XLR to a separate stereo input pair on the Classe.
Well to get that, all you need to do is change Stereo Signal from FRONT LEFT/RIGHT to DOWN-MIXED STEREO. This configures the Dedicated Stereo Analog outputs (both the RCA and the XLR pair) to operate INDEPENDENTLY of the Speaker Configuration settings that apply to the LF/RF outputs of the multi-channel set.
With Stereo Signal DOWN-MIXED STEREO set, the Dedicated Stereo XLR pair gets a Full Range signal. If you play multi-channel content, the XLR gets a "Stereo" down-mix, except wth the LFE channel discarded, but again it is a Full Range signal. The Sub setup, including Sub boost, is irrelevant because you are not listening to the Sub output of the OPPO. (The Sub RCA jack still GETS output according to the multi-channel configuration, but the Classe is not using that signal when you select its stereo XLR input pair.)
So MY recommendation would be to use these last two configuration. The first use the multi-channel outputs of the OPPO into the multi-channel input of the Classe, and gets you BOTH your #2
and your #3
configurations automagically, simply by playing stereo vs. multi-channel content. No settings changes and the Sub boost is correct for both.
Meanwhile you get your #1
configuration (2.0, only) by making JUST ONE setting change in the OPPO -- changing Stereo Signal from FRONT LEFT/RIGHT to DOWN-MIXED STEREO) while also switching your Classe to listen on its XLR stereo pair input instead of its multi-channel RCA input.
Again, all of the above assumes no bass management (Crossover processing) is enabled in the Classe, in the Sub, or in any other gadget in your signal path.