I recently put together a p-bass using various pieces bought from ebay. I have a no-name body, a dean neck, and a bridge from dragonfire guitar parts. Just recently (after attempting to lay down some tracks) I realized that even if I have the intonation setup correctly between the open string and its harmonic at the twelfth fret, numerous notes along the fretboard are out of tune. The seventh fret is the most prominent and is off by about 10 cents if the open string is perfectly tuned. My action is set at a very comfortable position and the truss rod is just slightly bowed, just as its supposed to be. Is there any way I can correct this or is it a lost cause?
Use a compensated nut.
Sounds like maybe the scale length of your neck is different from that of your bridge placement. Measure from where the string leaves the nut to the center of the 12th fret. It should be equal to the distance from the center of the 12th fret to where the string meets the bridge. You could just move your bridge to the correct spot if that's the case.
Looks like it is the bridge position. I'll need to move it back farther. Thanks for the help. I never thought of that, I just kind of used a spot, but that definitely makes sense. If this doesn't fix it, I'll have to look into a compensated nut.
So, I messed with the bridge placement and moved it so the saddles are about 34 inches away from the twelfth fret (actually had to move it closer to the neck, opposite of what I last posted). But now i am very confused. When my E string saddle is at exactly 34 inches from the nut, the twelfth fret is sharp by about 38 cents but the harmonic is perfect. The saddle needs to be moved about half an inch back for the twelfth fret and open note to be in tune. But moving it back that far leaves me where I started, with the same problem. What's going on?
The harmonic will always be in-tune no matter what. You either have no idea what you're doing and are doing a poor job explaining it, or the placement of the frets is off.
Yes, of course the harmonic is always in tune, I was thinking like an idiot. Now why do I have to move back the saddle so far for the twelfth fret to be in tune? Is it to compensate for the distance the string must be pushed down? A half an inch seems like a large distance to move the saddle back...