Truss Rod Adjustment

[bare_handed]

I recently acquired an '85 Alembic Persuader. The instrument itself is exquisite with a bird's eye maple top on a mahogany body. The problem with it is that the set up is atrocious. The problem is the neck itself. It's set so flat that I can't dig into the E or A strings without extreme fret rattle. It has two truss rods that obviously need adjusted. I've backed them both off a quarter turn and the difference is amazing. It's ALMOST exactly where I want it. My question is Do both truss rods have to be under the same tension? If so, how do I check this? Or can this set up actually add or subtract slight twist in the neck also? I have the set up almost where I want it now but want to make sure I'm not setting myself up for bigger problems further down the line

[bsee]

There's some info on the main site here:
http://alembic.com/support/care.html
 
but it doesn't say anything about relative tension between the rods, only which direction does what.
 
The good news, if you remain in doubt, is that Ohio happens to have more Alembic dealers than any other state, so professional assistance shouldn't be far away.  

[bob]

Congratulations on your Persuader, and your nearly perfect setup. There has been a lot of discussion on this subject, but the short answer for you is that you do not need to worry about getting exactly even tension on the two rods. (This isn't really a useful concept anyway, because depending on your neck it might require a little more on one side anyway, even if you were going for perfectly even relief across the neck.)
 
As long as you're talking about small differences (maybe up to a quarter turn or so), it's perfectly fine to set up for slightly more bow on the fat strings and keep the high string side a little flatter, for instance.
 
Once you get it to your liking, then you would usually make even adjustments to both rods to accomodate changes in weather, playing style, whatever. So you may see comments suggesting that you adjust them evenly, but that sort of assumes you already have it set up pretty well.
 
The only real exception is if you have a neck that is seriously twisted. The truss rods aren't intended for fixing a problem of this sort, and that should probably be addressed with a heat treatment or something.
-Bob

[flaxattack]

just got my orion 5 and its set with a slight bow
since my new bass was a 2000 model- i immediately went to put on elixir nanowebs- just a slight diiference on guages on the d and b string- and according to mica- it should change settings
note- if you buy elixirs- DO NOT BUY THE TAPER WOUNDS IF YOU CAN AVOID IT- saddle seating issue may arise.
but this is how i changed the strings
in this order
a-e-d-b-g-  there was no movment of the neck
i use a line 6 pod to play through, so i can monitor the fret intonation- one fret was off - the c on the b string- this probably is due to the saddle issue- but- if you can tell me you could hear the low c and tell me its ever  slightly sharp- youre a dog!