can audio shops tune your amps to whatever you want them to? if you want your sub amp at exactly 80hz (lpf) and your comp amp at 80hz (hpf) do they have a meter or something tellin them the frew? or do they just listen to it and put it to what they think is best?
most shops just listen and set it where it sounds decent.
but...if you go to a highend shop and get them to do a true SQ install (SQ competition grade), the might have an RTA that they use to set your crossover and equallizer points.