Merging cabinets

  • I recently downloaded Tills free cab pack. mainly I've been using Top Jimi's Caswell modded marshall pack (which I love) and I tried taking some of the merged versions of this amp and changing the cab to some of the ones I got from Till. I have the browser set to auto load so it's really easy to hear how much each cab affects the tone. some of the cabs sound truly excellent but here is my problem... once a cab is loaded I get an option to press soft button 2 to "merge" the profile. when I do this, it gets harsh anf much louder. what is the reason for this?