THANK YOU, MATT!
 
I was unaware of the "active monitor pad" feature. This drops the output by 20 dB, lowering the noise in the monitors by the same amount.
 
I am now running the master volume at -12 dB (haven't recalibrated yet but it sounds about right). I wish it could drop another 10 dB, but it's still a huge improvement (well, 20 dB to be exact). And I was THIS ][ CLOSE to ordering some in-line pads, so Matt's advice has also saved me 40 bucks.
 
That's twice now Focusrite support has come through for me, and this time I hadn't even contacted them! Way to go, Matt, and way to go, Focusrite.
 
aspenleaf, are  you using the monitor pad feature, or do the Equators just have less gain? BTW, I have my ADAMs set for -10 dB as well, which is as low as they'll go. 

I checked my Mix Control for the setting that Matt mentioned, but couldn't find it.  The Mix Control logo says "Scarlett Version".  Maybe the Scarlett version doesn't have that pad, although I don't know they would eliminate it.  I'm using the most current version.
 
Glad to hear that worked for you. 

I should have read the manual first.  I was looking in the settings tab, which only has the buffer size, but the -20 db pad is located just left of the volume knob in mix control.  I need to use mine without the pad.  With a normal mix in Sonar, my volume knob is at the 12 o'clock position to get an 80 db SPL, which is the level I like to mix at.  83 db is a bit too loud for me.

Glad you got it working better for you Bit.   It's a pretty cool unit.  I found the pre's pretty clean and neutral.