moving a mark IV around easily results in knobs being turned, GEQ moving a bit etc..not to mention every room you enter will have different properties, that will require adjusting on the amp...that being said, i've never heard my mark IV sound 'bad'..once the tubes are warmed up with a song or two of playing, it just sounds better and better throughout the gig...also realize when you turn your amp up, the tone will change..the louder you go, the less gain you'll actually need (and treble, as on the IV it almost doubles as gain on most channels)..so your settings at a bedroom / practice level, may not be the same as for loud..thats why i crank my amp, get my live settings, then for practice / rehearsals just turn it down, and deal with the 'slight' tone loss (to me, it is very, very negligible)
so my only good advice haha...write down all your settings...like to a T (aka treble - 6.8, bass, 4.2 etc)..take a pic if you have too..if you get to the gig, and its sounding flubby, roll off the bass a bit..just use your ears, you can hear what frequencies are coming out of the amp you've never heard out of it before, and that you don't like...good luck, i've gigged like 5 times with my MKIV now..never a problem at home, rehearsals or gigs. (inside and outside)
