I have a U-channel truss rod and I've got some questions about the installation of it: How should I route the channel? Completely square and open passing under the nut or stopping the channel before the end of the blank and drilling towards it for the adjustment nut? I made a quick sketch to explain what I mean: You can see the truss rod I have here: And another question: how do I prevent that the rod will buzz or rumble within it's aluminum channel? I am almost having nightmares of finishing the neck perfectly well, setting the bass up and discovering that on each strum the truss rod will mingle itself in the sound of my bass, ruining the whole instrument, basically. Ps.. one more thing, do you think I need graphite enforcement rods or is this too much for a 4 string hard maple neck and would it just kill some of the sustain?