ive recently acquired a used ibanez usa atk 5 string. the action is just too damn high for slapping and popping. heres the problem... the bass has the bunker tension free neck on it. meaning this thing doesnt have a truss rod. instead it has a 3/8" steel bar going through the neck, and is connected to a brass nut that divides the neck from the headstock. anyway, heres my problem. i put new strings on it, and they are heavier. (DAddario XL's, .050 G string to a .135 B string) and the neck has an insane relief now. theres an adjustment screw at the back of the heel, but i cant seem to get it any flatter than it already is... only more relief. because of this the bass needs a high action in order not to buzz like crazy on the upper frets (19-21). would replacing the strings with a much lighter gauge remedy this problem? like super soft XLs with a.040 G string and a .125 B? would this make the strings really "floppy" though?