Resistor position in passive crossover

As long as they don’t vibrate too much. The vibration of the solder joint can make the metal act funky(for lack of a better term) changing the resistance during compression and expansion. Overlap the two conductors to make a long solder joint so that doesn’t happen. You can always add wires to the resistors and mount them remotely. The additional wire won’t add to the resistance enough to worry about.