I'm having a odd intonation problem that before dropping the bass off at my luthier I wanted to share here. Bass Yamaha: BB435 less than a year old Strings: D'Addario Flats, strung through the body. Tuner: Korg Pitch Black, and Tech 21 DUG onboard tuner (both are consistent with each other) I'm noticing that my E and B String are going sharp around the 4th fret, but at the 12th fret and most everywhere else, the bass is dead-on. I've adjusted this a few times, and keep ending up at about the same spot. Did the setup myself, setup the neck relief at ~.015 at the 9th fret and have played around with it a bit to get a good feel/sound. Wondering if this could be a flatwound string thing? People talk about some flat wound sets having intonation issues;I've used Flats in the past, but always on fretless so this issue would have been masked. Considered that I could bend the strings by accident in a few places, but have been very conscious of this and fairly certain that's not happening while checking intonation. Maybe the 4th fret has a high spot? I don't feel any ramp... What do you guys think?