Yes but one of these is 1m the other .5m also these are XLR, therefore logically the only way to answer this specific question is to know the altitude and humidity of the room. Also it will be necessary to know the precise voltage run. A meter connected in series will do but it must read average not peak voltage! The trickiest part is to figure out how to read the meter, this absolutely must be done blind! If you see the meter this will bias your expectations and you may unconsciously tilt your head thus introducing a parallax angle that will completely ruin all accuracy and you will be forced to start all over again with new cables and blindfolds.
Either that or you could play music and listen, and when one day it sounds like the day before then shazzam! Settled in!
