Double Bass Bridge Position for tone

[Stuart.C]

I recently made a small adjustment on my bridge height. (with out marking the position) but when I played it felt like I had made no adjustment at all. I noticed that the bridge had also move towards the tail a couple mm too. seems to have compensated for the height increase
Anyway the sound changed noticeably as well. The attack was a little quicker and the balance between E,A and D,G changed.

So my question is this:
Is there a hard and fast rule about where the bridge should be?

Or do people make small adjustments (<5mm) until they find the best spot?

What directions make what kind of changes in relation to the sound post?

Thanks

Oh yeah I tried a search and the search on this site sucks. who wants every post with "bridge" and "position" in it.

 

[KUNGfuSHERIFF]

The sound post should be moved in relation to the bridge, not the other way around.

As a rule of thumb, the bridge should be centered between the ff-holes (assuming the neck set isn't crooked) and the feet should line up with the nicks on the ff-holes. The back (tailpiece) side of the bridge should stand 90 degrees off of the top.

 

[Greg Clinkingbeard]

The sound post should be moved in relation to the bridge, not the other way around.

As a rule of thumb, the bridge should be centered between the ff-holes (assuming the neck set isn't crooked) and the feet should line up with the nicks on the ff-holes. The back (tailpiece) side of the bridge should stand 90 degrees off of the top.

An imaginary line connecting the inside nicks should go through the center of the bridge feet. A line connecting the outer nicks will approximately line up with the tops of the feet. Assuming (big assumption) that the neck and fingerboard alignment are correct, and the bridge is made correctly, a centered bridge with the adjusters even will center the strings with equal distances between the outside strings and fingerboard edge.

There are many things in play here.

I rarely move a bridge from the 'correct' position.

 

[Stuart.C]

An imaginary line connecting the inside nicks should go through the center of the bridge feet. A line connecting the outer nicks will approximately line up with the tops of the feet.

Thanks. I was starting to drive my self a little crazy making small adjustments. I was amazed how much a difference in tone and balance it made.
But I'll just position it like you said and be done with it. Maybe go to my luthier and play a little with the sound post.

 

[MikeCanada]

Provided your bass is setup/made "right" the above information is where your bridge is intended to go. There are some rare cases where the bridge is not in that spot, but these tend to be exceptions like an older and large instrument that has been cut down to a more moderate size and even then they try to keep it there. What you are doing by moving the bridge around is similar to what would be done with a sound post adjustment where again there is a standard "right" place for it, although small adjustments can be made and often do have a significant impact.

Some basses even have a summer/winter bridge and/or a summer/winter sound post, for when the climate and the instrument shift dramatically. Many players in parts of North America with large seasonal changes opt for bridge adjusters, where they are quite rare in Europe and other parts of the world where they either are not deemed necessary, or believed to be detrimental to the sound.

 

[Chris Fitzgerald]

I had a carved Czech bass way back where the bass response of the E string could be massively manipulated by scooting the feet a mm. or so over towards the bass side. I never figured out how that worked, but somehow it just about doubled the volume and heft of the E string. I realize that there's science to all of this, but in my mind it will also be part voodoo. This makes Arnold and Jeff and Nnick and Jake witch doctors of a sort, no?

 

[drurb]

Provided your bass is setup/made "right" the above information is where your bridge is intended to go. There are some rare cases where the bridge is not in that spot, but these tend to be exceptions like an older and large instrument that has been cut down to a more moderate size and even then they try to keep it there. What you are doing by moving the bridge around is similar to what would be done with a sound post adjustment where again there is a standard "right" place for it, although small adjustments can be made and often do have a significant impact.

Some basses even have a summer/winter bridge and/or a summer/winter sound post, for when the climate and the instrument shift dramatically. Many players in parts of North America with large seasonal changes opt for bridge adjusters, where they are quite rare in Europe and other parts of the world where they either are not deemed necessary, or believed to be detrimental to the sound.

On target, as usual, Mike but I'd like to clarify that the "standard" placement of the bridge is much more firm than is the "standard" placement of the sound post, which is considered as a starting point.

 

[KUNGfuSHERIFF]

Oh, great. Now I have to spend the rest of the morning thinking about those fellas singing "Ooh-eee, ooh-ah-ah, ting-tang, walla-walla bing-bang."

 

[Jake deVilliers]

Oh, great. Now I have to spend the rest of the morning thinking about those fellas singing "Ooh-eee, ooh-ah-ah, ting-tang, walla-walla bing-bang."

 

[MikeCanada]

Good Dr., I could have been clearer about that. I was trying to suggest non-"standard" bridge placement is a rare exception, but could have put more emphasis on it being a very firm rule that is occasionally broken, not just a pretty good guideline.

As far as soundpost adjustments, I've heard of a few different schools of thought and don't know a whole lot about moving it around to make anything close to authoritative comments. I have heard that some basses it is more about location, where having it slightly lower or slightly more towards the centre of "standard" is what that particular instrument needs. I have also heard some basses it is more about tension, where the tightness is more of a concern than the location. I am also guessing that is mostly a difference of philosophy, as it would be next to impossible to adjust one without influencing the other.

I have been considering a soundpost adjustment and a few other little things on my instrument, but I am worried about it sounding worse instead of better. When the new strings arrive and go on we'll see if that solves the problems, as imagined as they might be.

 

[Stuart.C]

bass response of the E string could be massively manipulated by scooting the feet a mm

Yeah that's what I find too. Feels like there a sweet spot of the bass side foot to line up on top of the bass bar.

I used a string from outer nick to outer nick and lined the front of the feet up to that. It puts the inner nick just slightly off center so bridge is a little closer to the sound post then if I centered it on the inner nicks. This works really well.

Now I can stop messing with this and get back to playing

Thanks

 

[bassfacer22]

I have a small body eminence bass and I constantly take off the bridge.. Every time I've experienced major changes sound and tone just depending on where I put the bridge..

Maybe my situation is worse because it's a smaller body and more small movements would affect the tension, tone, and volume..

 

[DoubleMIDI]

Mark a good position for your bridge on the top and take something with you to check if the bridge is rectangular to the top. And check and correct again and again when you tune your strings up. That will help to keep the variance low.

The greatest influence on your sound comes from the relative position of the treble bridge foot to the soundpost. Since the soundpost is more or less fixed on your Eminence, the position of the bridge influences the sound as much as the position of the soundpost on an acoustic upright bass.

 

[james condino]

In a perfect world, all bass soundhole notches would be cut in the proper location for the bridge and scale length after everything else was setup well. More common factory produced basses have the holes cut with a router before the top is even installed, so the best position for your bass and your needs often requires a bit of trial and error until you get the maximum outcome for you as a player and with that individual bass. Scale length, bridge position, bridge height, and soundpost position are all part of the final voice.

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