The OP isn't willing to try much.
SPL meter? Nope. He's a professional musician, won't try the SPL meter. Taking the cover off the amp? Nope, no tool. Unwilling to go to the store to buy a set of allen keys. Besides, he isn't good at taking the cover off, he has the dexterity to be a musician but he can't turn a screw.
(Hardware stores will have both US and metric sizes by the way -- really easy investment.)
Likes swapping speaker cables though.
SPL meter? Nope. He's a professional musician, won't try the SPL meter. Taking the cover off the amp? Nope, no tool. Unwilling to go to the store to buy a set of allen keys. Besides, he isn't good at taking the cover off, he has the dexterity to be a musician but he can't turn a screw.
(Hardware stores will have both US and metric sizes by the way -- really easy investment.)
Likes swapping speaker cables though.