Originally Posted by mt14942
Bob since I have a Rel sub and they have the dual connection option one for the .1 and the second which is based on the connection directly to the front left and right speaker posts on my Amp. I wouldn't think I want to turn it off. So I guess I would need to turn it off in the Oppo menu. I have been listening to 2-channel cd's and sacd's and it sounds fine w/o turning off the sub. I guess technically I should turn the sub off? By the way Thanks so much in advising me about lowering the headphone amp volume from it's default of 75. I changed to 50 before plugging in my headphones and it was way too loud and wound up settling on a volume of 28. Does this seem odd or is this normal? I guess it depends on your headphones and although the Master & Dynamic M-40 headphones I used is not a cheap headphone its not expensive. I guess or more high end or more power hungry headphones the 75 volume might be more suitable. I will say at the 28 volume setting it did sound very good although I guess I expected to be blown away, using the Oppo 205 DAC and amp, since previously I had only listened to these headphones with music I downloaded to my Samsung Galaxy S8 phone.
You are going to have to think through the signal path and whether or not you want Crossover processing done for EACH of your usage configurations.
Do not do Crossover processing in more than one place at the same time.
Do not send full frequency range to your speakers AND ALSO steered bass from those speaker channels to the Sub via separate connection.
Most subs will expect you to use their LFE input -- and ONLY that input -- if you are having Crossover processing done by something OTHER than the Sub. The LFE and steered bass (due to that Crossover processing) come into the Sub together on that LFE input. The Sub should NOT be in the path of the speaker wires to the speakers if you are doing this.
For Subs that have high level inputs -- i.e., intended to be in the path of the speaker wires to the speakers themselves -- you'll have to find out from the Sub's documentation whether they ALSO want to get LFE separately the LFE input. But if so, that LFE connection must not also carry steered bass because the Sub is likely doing that itself on its high level inputs.
This is NOT simple stuff. And there are many possible pitfalls when you try to wire for multiple different signal flows.
Map out all the signal flows you want to use and ask, at each step, just what the heck is on those wires? Has Crossover processing already happened? Is LFE content already present?
And then there's the whole problem of Sub Boost and where it gets added. This will likely be DIFFERENT for the different signal flows, depending on where Crossover processing happening and whether LFE content has already been mixed in or not. Which can be a real pain in the neck.