Has anyone got any advice re twin truss rods? I have a spector q6 that I got a year or so back that has two truss rods .. I don't know how to determine how loose or tight each one is .. and i'm guesssing there must be some sort of "perfect" adjustment between the two    ? Is there more tension on the lower strings?  Should that rod (b string side) be tighter? The neck is good and stable and at nearly 20 years old hopefuly ok for the future..  but are there any signs to lookout for