Double Bass Bridge/Nut Diagnosis

[Rompi]

Unfortunately, the bridge and soundpost recently collapsed on my bass. I was able to get a luthier to reset the soundpost and bridge, but the bass has not been playing as well since. I have found that the strings have been stiffer/harder to play and it has been more difficult to get a full sound out of the instrument. The overtones on the instrument are also not quite as resonant. In addition, the E string is rattling quite a lot, especially on the note F, which might relate more to the fingerboard. I have been using obligatos with an oliv G

Here are some photos of the bridge as well as the nut. I know it's hard to diagnose much from just a picture, but if anything looks obviously wrong, please let me know! I can only eyeball it, but it looks like the soundpost is about half its diameter below the G side bridge foot.

I noticed the bridge had been placed slightly closer to the the E string side after repair, but I have since centred it (not sure if this would have a large effect). A flat sheet of paper will go across both feet of the bridge straight and cannot fit under the bridge feet, so I don't think the problem lies there. Is it possible for the bridge to be too far North or South (toward the neck vs toward the tailpiece)? I know the f hole notches on my bass aren't perfectly in line with each other; I've lined them up as best I can though. I've also included photos of the nut just in case a problem lies there (photo added after changing the dying D string for an oliv D). Any help is appreciate, thank you in advance!

 

[Chris Fitzgerald]

I'll let the knowledgeable folks speak to the sound post issues, although it's hard to tell from a picture. I will say, though, that any change in the placement of the bridge - whether north/south or east/west - will have a noticeable effect on the feel of the bass to the player.

To the east/west issue, there are a couple of things that happen when the bridge moves in either direction. First, the string heights change in relation to the board because the board is generally much more curved than the top. I always try to be aware of how much "free board" there is on either outside string (i.e. - empty space between the G or E and the side of the board). If I bump my bass and the bridge moves in either direction, it won't feel or sound right until I get it back where I was accustomed to it.

The other thing that happens when you bridge moves east or west is the whole leverage of the top changes since the bass foot is vibrating in relation to the bass bar and the treble foot is vibrating in relation to the soundpost. Any movement makes it feel "wrong" (i.e. different) to the player, who has become used to a certain type of response. I had an old Czech bass years ago that only spoke the way I liked on the E string if the bridge was scooted a couple of mm toward the bass side. I never figured out why.

Good luck!

 

[Greg Clinkingbeard]

The bridge may be pulled slightly toward the fingerboard. If it is, it will raise the strings and it will feel stiffer. The back of the bridge should be at a right angle to the top on the tailpiece side.
As far as the rattling sound you are hearing on the E string, it is possible you have a bump in the fingerboard near the nut. If you have a short metal ruler, you might check that. I often see unrelated problems that pop up at the same time.
I have a bass on the bench now which developed a bump at half position and it’s been setup for over five years. Don’t rule anything out without checking.

 

[KUNGfuSHERIFF]

I can’t see anything obviously amiss with the bridge.

Are you sure that the soundpost is placed correctly?

 

[Fran Diaz]

if the sound post really is only half its diameter south of the bridge I think that might be worth a look. Pick up a piece of card board, from a cereal box for example, make a straight cut so that you can put one side into the G side F hole and the other south of the bridge. When the part in the f hole touches the sound post the other will show how far it is from the bridge. measure it and let us know.

 

[Neil Pye]

That's where I would start too. The bridge looks pretty well placed to me, but the soundpost looks very close to the bridge foot. That might well make the whole thing feel stiff, tight and unresponsive.

 

[wathaet]

Hard to tell, but the post looks very far in. It should be directly south of the bridge as a default then maybe some small adjustments east/west