Sorry, not very 'short' jimr but here goes.
(And if I did it wrong, they'll let us know...it was my first. )
I picked up a Radio Shack Sound Lever Meter, the cheaper one (aprox. 40). The other model was ummm Digital? The Outlaw Owner’s Manuel, (thank you Outlaw!) does walk you right through it on pg. 27.
Outlaw recommends calibrating to 75db/SPL

Turn you 950 & ? amp on with NO source playing.
Set main volume control on the 950 to 0dB

Sit in your central listening position holding the meter at ear height.
Outlaw states: point the meter at ear level towards your CEILING.
The instructions that come with my meter say point the meter AT the speaker.
I used Outlaws recommendation and pointed to the ceiling.

Set your meter to Slow response and ‘C” weighting.
Set range on your meter to 70 (and work up)
Or 80 (and work down)
(You set your meter using the big black scroll button on the meter marked: Range.)

I won’t walk the menus on the 950 (it will be in your manual)
But access Channel Calib Menu, which looks like
> Left Front: 0db
Center Front: 0db
Etc.
As you use your remote to scroll the > onto each choice press select for each speaker in turn, you will hear the fairly loud test tone through the speaker selected.
Your meter needle will jump to ‘something’.
Use the < > (after hitting select first on your 950 remote) to move your volume up or down for that particular speaker till the sound meter needle swings to 0.
If you have selected 70 range on your meter 0 = 70.
If you have selected 80 range on your meter 0 = 80.
Work up or down depending on your starting choice till the needle registers: 75dB.

I thought the trim feature on the 950 was separate from the Channel Calb, entirely, to be used to tweak something temporally whilst still keeping Calb set at its original specs. I noticed after calibrating Trim dB’s = what you set in Channel Calb.
One thing I ran into is something the guys here could prob. answer. I got a test tone for the subwoofer (so I assumed I should calibrate it also) but this caused my needle to peg right; even when I adjusted the SW volume to its lowest setting –15dB.
Puzzled I tried setting my meter to “A” weighting, then I could get the needle to swing to 0 using volume controls. This still gave me a little too much LF on some viewing, so I went back and lowered the dB on it the next day.

Is ‘A’ weighting normally used for the SW, the meter or Outlaw manuals did not explain; or did I mishandle this portion?