Originally Posted by Bigus
volume on the Focusrite should be increased until you are just below the level of clipping the minidsp input, and then left alone.
With a 0dbFS square-wave signal, with all filters and EQ disabled.
With the filters and EQ re-enabled, and a sinewave within the bandpass of said filters, then you adjust the miniDSP so that it's output doesn't clip.
Setting the amp is more tricky because you need an o-scope. But basically it would be a max-output level.
In my system I leave my Oppo 105 at 100% and my DCX's at 0db.
I then set the amp's gain to max, and the amp's sensitivity to something reasonable.
In JRiver or Foobar in WASAPI exclusive-mode I set the windows and player volumes at 0db as well.
I then adjust my Emotiva XSP-1 to whatever master volume I want (+6db is 100% power, I rarely go above 25-50% power.)
I find that this gives the best SQ for a reasonably level of trade-off.
For movies I usually have to lower the Oppo to 50-70%, depending on how loud the bluray mix was. The emotiva at 0db and DCX at 0db and amps remain unchanged.
So the Oppo is my master volume for movies, and the XSP-1 is the master volume for music.
Sometimes for music I'll just set the XSP-1 to 0-3db, and use the player to adjust the master volume, it sounds really-really good when I do this (for some reason that I an unable to quantify), but this is extremely dangerous as one wrong click of the mouse could send 40-50kW into the speakers
If music and movies didn't have such wildly varying mix levels and assuming the DCX's came with a remote, then I'd just use that. But that just ain't EVER happening.
The LFE channel on most movies can vary by as much as 20db, which I find is BEYOND FRUSTRATING.
To optimize the bass you basically have to do spectral analysis on it before watching, LOL, otherwise you'll get sub-optimal bass.
-My 2 cents
That said, I would love to get my hands on $5000 worth of Motu in/out's. That would probably be more-optimal, for both SNR and convenience than 10 DCX's and XSP-1's. I'd also like a 8802 instead of a 105 and 3 cleanboxes. A person can dream can't they?