Soundpost Fit

[bassist1962]

The bass I own has been in my family since before I was born, so it is around fifty years old at least. When I took posession of the instrument, I was told that there was a setter with it because the soundpost kept falling. The last time I remember the bass being set up was around thirty years ago. since that time I don't remember the soundpost being an issue. My question is does this have to do with the wood drying and shrinking over time? Are there other factors involved? I plan on getting it to a luthier shortly after the first of the year to assess repairs needed. I was told by him to loosen the strings to ease tension so the seams would not open any more than they already have. I tuned down a fifth, and the soundpost is still in position. I am just wondering what is happening here. Thanks for your input.

[Jeff Bollbach]

I think what is going on is you can't expect to have the same soundpost for 50 years.

[Silversorcerer]

I'm thinking if you have seams opening, take all the tension off the instrument. The falling soundpost issue is minor compared to the plates separating from the ribs. Your heirloom needs a thorough tune up, not just a tuning down.

[bassist1962]

I plan on having as much done as I can possibly afford at this time. Pretty much getting it overhauled. Jeff, How often should a soundpost be changed, and how can you tell? I guess my question is If the wood on the rest of the bass has dried and shrunk, then shouldn't the soundpost (being wood itself) have done the same thing?

[Jeff Bollbach]

Originally Posted by bassist1962

I plan on having as much done as I can possibly afford at this time. Pretty much getting it overhauled. Jeff, How often should a soundpost be changed, and how can you tell? I guess my question is If the wood on the rest of the bass has dried and shrunk, then shouldn't the soundpost (being wood itself) have done the same thing?

You can't say how often a post should be changed like you can for tires or oil. I can say that it would be prudent to have it checked by someone you trust once a year or so. Typically the most imortant time to check a post is when you start to heat your space[thereby lowering your humidity].

[Bob Branstetter]

This has nothing to do with the question at hand, but back in the days before adjustable bridges became common, it was not unusual for players to have 3 or 4 different soundposts which they would swap out whenever the seasons changed and made the strings go up or down excessively in relation to the fingerboard. I don't know too many bass players who do that today, but it is still a good idea for some basses that change greatly with the seasons. I keep 2 posts for my personal bass. Not so much for the string height, but because the bass simply sounds better with a soundpost of the right length (i.e. fitted properly).

[bassist1962]

Originally Posted by Bob Branstetter

This has nothing to do with the question at hand, but back in the days before adjustable bridges became common, it was not unusual for players to have 3 or 4 different soundposts which they would swap out whenever the seasons changed and made the strings go up or down excessively in relation to the fingerboard. I don't know too many bass players who do that today, but it is still a good idea for some basses that change greatly with the seasons. I keep 2 posts for my personal bass. Not so much for the string height, but because the bass simply sounds better with a soundpost of the right length (i.e. fitted properly).

Kind of like different rosins for different seasons?

[bilco]

I am sure every bass is different, but is there a general rule of thumb for how the tone changes when the soundpost is moved one direction or the other from the bridge?

Thanks,
Bill Colbert

[Bob Branstetter]

Originally Posted by bilco

I am sure every bass is different, but is there a general rule of thumb for how the tone changes when the soundpost is moved one direction or the other from the bridge?

Thanks,
Bill Colbert

Here is an article by David Gage that covers the generalities of sound posts.

[bilco]

Thanks Bob; those are great articles! I also found the Newbie soundpost threads and read those as well. I will not be moving the soundpost myselfm that's for sure!

Bill Colbert

[Batbass]

Originally Posted by Bob Branstetter

This has nothing to do with the question at hand, but back in the days before adjustable bridges became common, it was not unusual for players to have 3 or 4 different soundposts which they would swap out whenever the seasons changed and made the strings go up or down excessively in relation to the fingerboard. I don't know too many bass players who do that today, but it is still a good idea for some basses that change greatly with the seasons. I keep 2 posts for my personal bass. Not so much for the string height, but because the bass simply sounds better with a soundpost of the right length (i.e. fitted properly).

Could you please explain how humidity changes affect the bass?
More humidity=top raises=need a slight longer soundpost or what ?
Thanks a lot in advance

[Batbass]

Ah...
Luthier Bruno Destrez told me Marc Johnson for his bass has three different soundpost!

[Bob Branstetter]

Originally Posted by Batbass

Could you please explain how humidity changes affect the bass?
More humidity=top raises=need a slight longer soundpost or what ?

That's pretty much the way it works. However, not every bass responds the same way or to the same degree when it comes to humidity/season changes. If you take the tension off the top table and the soundpost falls ...

[Batbass]

Originally Posted by Bob Branstetter

That's pretty much the way it works. However, not every bass responds the same way or to the same degree when it comes to humidity/season changes. If you take the tension off the top table and the soundpost falls ...

Thanks!!
Also, is it possible, when in summer string tension get lower , to try first to change soundpost position instead to change soundpost. If yes, which is the best way to act?

[Bob Branstetter]

Originally Posted by Batbass

Thanks!!
Also, is it possible, when in summer string tension get lower , to try first to change soundpost position instead to change soundpost. If yes, which is the best way to act?

Sure, but keep in mind that the soundpost actually only "fits" in one spot because of the compound curvature of the top AND most backs (without a platform). A little bit of change in position may not make much difference, but if the soundpost is very loose in it's proper position, then taking up the "slack" by moving the post will likely cause a negative change in the sound of the instrument. If the post is loose enough that it would fall without the tension from the strings, a new longer post is a better solution. However, in my shop, I would say that less than 10% of my customers actually change soundposts with the seasons. Some would rather live with the seasonal changes rather than having to visit their luthier whenever the season changes (again). YMMV

[Batbass]

Originally Posted by Bob Branstetter

Sure, but keep in mind that the soundpost actually only "fits" in one spot because of the compound curvature of the top AND most backs (without a platform). A little bit of change in position may not make much difference, but if the soundpost is very loose in it's proper position, then taking up the "slack" by moving the post will likely cause a negative change in the sound of the instrument. If the post is loose enough that it would fall without the tension from the strings, a new longer post is a better solution. However, in my shop, I would say that less than 10% of my customers actually change soundposts with the seasons. Some would rather live with the seasonal changes rather than having to visit their luthier whenever the season changes (again). YMMV

Thanks Bob,
everything is much clearer now!