clarky
Axe-Master
You can get in the ballpark simpler than I showed in the video linked above. Just hook up the output of your Axe-FX II to a mixer with a meter bridge. I put a piece of tape to mark my 'start' tone level, normally your CLEANEST tone. I shoot to have this work when the output knob on the Axe-FX at noon for direct-to-FOH adjustability maximization.
I then run through each tone and get them close - without listening at all. THEN I check with the db meter (at least 90db+) and judge by ear also.
Assuming you have chosen your cab IR's well, you'd be surprised how fast this can make the process and how accurate it can be.
Scott - a little question..
as you're using an initial visual check first for level balancing, wouldn't you find that presets with a significantly stronger low end would come up quieter than those that are more mid's strong??
because I'd have expected presets with strong lows to move the meter more than those that are more gentle with the lows