One speaker is louder than the other

Have you tried other speakers to see if it's your preamp/amp? It could be a bad tube, or maybe some pots that need cleaned.

You've swapped um so you know it isnt your amp. You've run a mono source so you know the inputs are equal. Your old speakers had the same volume in the same positions, so it isn't the room. Capacitor/resistor would be in xover I guess so is it part of the frequency range that's louder in one, or the whole spectrum? No buzzing in the softer speaker? Those are all the things I can think of.. good luck and hopefully someone can supply a definitive answer for you.

I have checked the other parts of my system, the problem is within 1 speaker. no buzzing. I am running them with a celestion sub with it own amp from 40 hz and below so the Speaker is ruuning essenitially full range.