Double Bass Carved Bass Top Sag?

[mikeowen17]

I just purchased a 20 yr old Czech carved bass. As I’ve played it more I noticed that the inner (closest to strings) edges of the F holes sits lower than the outer. This got me wondering if the top was sagging a little (my relative inexperience buying uprights is showing here). The bass was in gage’s shop a month ago having a crack repaired (by prev owner) so I called them but they didn’t recall any sagging issues with the bass - mentioning that it may be the way the top on this particular instrument sits. They did offer to take a look if I bring it in, which I may do, but thought I’d post it here for opinions also.

I want to change the current strings (Zyex) for Spiros, but I’m reluctant to add higher tension til I’m certain it’s stable.

The bass came with an 4 year old appraisal from Gage which mentioned a sprung bass bar - could that be at play here?

 

[SAlcott]

"Sprung" refers to a technique used by some luthiers when installing a bass bar. There is some disagreement as to whether it's a good idea.

Let the guys at Gage's have a look.

 

[Eric Hochberg]

Jeff Bollbach Luthier, Inc.: Luthier Rant

You may want to bring it to him. He's on Long Island, I think. Excellent reputation.

 

[Steve Swan]

I would not worry much. This looks like it is well within the range of normal movement. Getting it checked out by a professional luthier with a lot of experience will be a confidence builder. Let us know how it works out!