Bent neck and/or fingerboard

[jimconklin]

I am new to the double bass. I bought a used one recently and learned that some bassists were using strings tuned in fifths. I bought a set and installed them. The strings seemed too high for bowing and I cut down the bridge. As I brought the strings up to pitch I heard creaks and cracks. The strings now were higher over the fingerboard than when I had measured to cut the bridge. When I laid a straight edge along the fingerboard I saw there was quite a gap where the neck joins the body. I loosened the strings and removed the bridge. When I put the straight edge along the fingerboard a few hours later I saw that the fingerboard was fairly straight again but there was a noticeable upward curvature in the lower couple of inches. I wonder if the cracking noises I heard indicate glued joints coming undone somewhere in the interior, say at the neck, and whether I will have to install strings with softer (gut?) interiors for lower tension at pitch.

[PNeher]

Yes, the neck is coming out of its mortise. Get the bass to a repair person (luthier) IMMEDIATELY! Lower tension strings will help but only temporarily.

Bass strings are rarely sold to be tuned (as a normal set) in fifths! You can use a solo string on top (A), then a regular orchestral D 2nd, then tune a regular A down to G, then get a long E string (for extensions) for low C. This is one-octave below cello. It takes a bit to get used to but, yes, many players are doing this tuning now.

Best of luck!
PN