Double Bass Bass repair book?

[Felessan]

Although it is usually not necessary to use a spreader when fitting bass bridges, it is no myth that a spreader is useful in fitting certain types of bridges on some instruments. It all depends on the design of the bridge and the instrument upon which the bridge is being fitted. I frequently use a bridge spreader when fitting Belgian style cello bridges especially if the instrument top table has a high arch.

Bob, thanks for that picture, that helps a lot, as well as your explanation! That does make a lot of sense to me, and jives with what I've learned so far about luthiery.

Science and violins aren't good bedfellows.

Feel free to disagree, but it is my opinion that science is necessary for the complete understanding of how a _physical_ system operates--such as a violin.

I can't give you any science but having fitted many bridges I can tell you what works and what causes problems.

I appreciate your experience! What problems do you mean exactly? Is the problem something that effects the use of the instrument, or is it something that the customer perceives is a problem, but isn't involved in the actual mechanics of making the instrument function? Customer service is at the top of the list of concerns when running a business such as luthiery. "Problems" are often subjective--meaning they are often in the mind of the beholder. Once your perspective or knowledge base changes, the problem may no longer exist, so the bridge feet needing to fit on the sides may be all voodoo or aesthetics, and not change the function of the instrument.

Oh, but I could direct your attention to the photo at the top of this thread showing what happens when a spreader isn't used.

What I see in the photo is a foot with the outer edge lifted up a bit. This could be easily caused by a wayward scraper or piece of sandpaper, bridge legs that don't come down straight (V-shaped rather than U-shaped legs), or even by an upward-sloping outer foot edge--though the latter would only exhibit the "problem" over a longer period of time than this bridge has supposedly been on this bass.

The picture doesn't show us how well the bridge feet fit on the front and back edges; it only shows one side. The front and back edges of the bridge feet are where all of the action is. The sides of the bridge feet don't help drive the top, they just add mass to the bridge. Granted, it isn't useful to have that mass flapping around on the edge there, but it only effectively reduces the footprint of that bridge leg a millimeter or two. Some people may call this significant, others may not.

If there are adjusters in the legs, the spreader is not necessary.

Are you insinuating that you fit bridge feet after they've been cut from the bridge proper?

Edit: I am having a crabby day....

I'm sorry for sounding like a know-it-all *******. It's what I do.

thus the following statement:

It seems kind of odd that you, who apparently have only watched a bridge being fit, would tell me, who has fit many and has to stake my reputation on proper fit, that it is not necessary.

What is your experience? Do people on here know you and can verify that you do excellent, world-class double bass setups? If so, then I am glad that your methods work wonderfully for you. Would you explain why and how your method is better? I would appreciate hearing it.

I've made my experience plain (in my profile). However, I have omitted that I've been studying luthiery on a very part-time basis with a heavy emphasis on "what exactly it is that makes a bass work well." If I were to say it another way, I am studying what is necessary for the power of the string vibration to be transferred most effectively to the top plate (the top plate being the primary source of sound on a double bass) and how to tune the bass to the player's individual specifications as suits their style of playing.

I've omitted this information because, up until now, I haven't found any reason to share it with anyone and I haven't felt like I've read anything that flatly contradicts what I've been learning.

Thus, we come back to my original statement:
"If someone can give me some plausible (hopefully scientific or experimental) reasoning, I'll gladly reconsider."

You've given me some unsubstantiated evidence that you have performed a lot of experiments and found that without a spreader, you see the "problem" as it is shown in the picture, and that "problem" causes the bass to function less efficiently. Can anyone explain and support this assertion?

Now, on my very own bass (as well as all of the LA phil basses I've seen come through the shop), a spreader was NOT used during bridge fitting, and this "problem" is nowhere in evidence. On top of that, all of these basses I've seen that have not used a spreader during bridge fitting have performed magnificently by professional orchestral standards. The LA pros use these basses, and I've played a few of them myself, and watched them get set up. That's my experimental evidence.

Or maybe you were just trying to dispel a myth for the good of those who like to watch their luthier work.

I'm not sure I understand exactly what you mean by this statement. I'll take it as a goodly gesture until I hear otherwise.

I realize this could get heated, but that's not my intention with any of these sentences I'm writing, so please, let's have a scholarly discourse here. I would genuinely like to hear your responses to this issue, and would gladly agree to disagree if it comes down to it.

-Trevor

 

[Matthew Tucker]

Age:26
Sex:Male
Location :Long Beach, CA
Current Setup:
Bass #1: labeled "1854, Bruxelles" (Brussels, Belguim)
Bass #2: Mid-20th Century 5/8 German shop bass, Labeled Götz, made by Wilfer

Bow #1: David Forbes, Oberlin 2008, French style
Bow #2: Finale carbon fiber French bow
Bow #3: Finale carbon fiber German bow

Strings:
- Pirastro Original Flexocore (royal blue-ish) w/ Pirastro Permanent low-C
- Pirastro Flexocore Solo Set (red)
- Thomastik Bel Canto (not too happy with the feel of these, further testing is in order... they sound great though!)
- Pirasto Evah Pirazzi
- Pirastro Original Flatchrome

Gibson Les Paul Recording Bass Guitar - solid mohogany, it's a beast!Previously owned gear:I've never sold a piece of gear, so these are currently owned and mostly seldom used:

Bow: made by Kolstein - #163. (this one: Invalid Link Removed)
A few handfuls of Microphones
Seventh Circle Audio Mic Preamps
Zoom H4
Studiomaster Compressor
A few low-end electric guitars
M-Audio Delta 1010 (2)G.A.S. List:My wish list:

Nice converters (AD, DA)
A few fantastic microphones
A contrabass that has that deep orchestral sound (my current bass is very nice, but you know the sound I'm talking about... that old Italian bass sound...)Gigs, Bands, & Ensembles:Working full time as an engineer. Not fun. Going back to grad school. : DInfluences and Teachers:Teachers:
Clifton Swanson (Cal Poly SLO)
Ken Hustad (Cal Poly SLO)
Nico Abondolo (USC)
Bruce Moyer (SJSU)
Barry Lieberman (UW) (Current Teacher)
Bruce Bransby (IU)
Stefano Scodanibbio (Italy)

Influences:
Edgar Meyer
Renaud Garcia-FonsOther Hobbies & Interests:BMW e28 535i, Electrical Engineering (hobby), AudiophileAvailable for instruction:WashingtonAreas of Instruction:ouble Bass (Classical), Bass GuitarTeaching Credentials:M.M. Strings Performance (2010) from University of Washington, Seattle

B.A. Music and B.S. Electrical Engineering from California Polytechnic State University San Luis Obispo

-Played bass with the San Luis Obispo Symphony for 4 years.

-Principal bass of Cal Poly Symphony, Wind Ensemble, University Jazz Band

-Founder and leader of Cal Poly Bass Ensemble

I can also teach guitar (my first instrument), beginning piano, music theory, counterpoint, orchestration, and composing.

Holy cow, look at that experience! I never knew that the top plate was the primary source of sound on a double bass. All these years I thought it was the end pin.

Ken, you better not even try to explain that if you are using a bridge with feet that are the slightest bit flexible, or if the top flexes under string pressure, then a spreader can help the luthier get a good fit. Where's your evidence, Ken? And stop that infernal insinuating; its confusing the young chap ...

(Oh and you might as well close your shop, too ... unless you too can find out "what is necessary for the power of the string vibration to be transferred most effectively to the top plate [...] and how to tune the bass to the player's individual specifications as suits their style of playing" )

 

[Felessan]

Holy cow, look at that experience! I never knew that the top plate was the primary source of sound on a double bass. All these years I thought it was the end pin.

Ken, you better not even try to explain that if you are using a bridge with feet that are the slightest bit flexible, or if the top flexes under string pressure, then a spreader can help the luthier get a good fit. Where's your evidence, Ken? And stop that infernal insinuating; its confusing the young chap ...

(Oh and you might as well close your shop, too ... unless you too can find out "what is necessary for the power of the string vibration to be transferred most effectively to the top plate [...] and how to tune the bass to the player's individual specifications as suits their style of playing" )

Uh, thanks for that. Har, har. If you simply must be patronizing in the face of someone who is trying to learn, that's your prerogative. For what it's worth, I've been following your bass-building project, Matt, with great interest, and I usually enjoy your posts.

It's the "insinuating" (insinuating that I know what you're talking about without clarification and explanation, as well as the insinuation that an established practice is best) as you call it, that I have issues with.

Ken didn't explain anything, he told. I didn't learn anything from his post. I learned something from Bob's post. That's all.


Now, back to informing people:

In the middle of Matt's witty post, he said this:

if you are using a bridge with feet that are the slightest bit flexible, or if the top flexes under string pressure, then a spreader can help the luthier get a good fit.

That's actually a good answer. Thanks Matt. How often do you encounter this scenario? You say a spreader "can help." How do you make that judgement call? What criteria do you look for?

-Trevor

 

[Matthew Tucker]

You make a judgement call by holding the bridge, pressing the belly, looking at it from all angles.

As Ken said in his first post "the the outside edges of your feet don't fit the top contour. This is most likely because the legs were not spread apart by wedging a rod in there when fitting. And then when the string pressure was applied the feet spread and the the gap formed."

That's actually a good answer too.

A deeply arched belly may cause the bridge feet to separate more under string pressure than a flatter belly. And a higher arched bridge may be more flexible than a squatter one. But maybe not. That's where the luthier's skill comes in.

 

[Felessan]

You make a judgement call by holding the bridge, pressing the belly, looking at it from all angles.

Makes sense. Thanks for the answer.

As Ken said in his first post "the the outside edges of your feet don't fit the top contour. This is most likely because the legs were not spread apart by wedging a rod in there when fitting. And then when the string pressure was applied the feet spread and the the gap formed."

That's actually a good answer too.

Well, if you read my first response, I say that this response flatly contradicts what I've learned, in these words: "The string pressure doesn't cause the legs of a well-fitted bridge to spread. "

Clearly, now, thanks to you and Bob, there are exceptions I was unaware of mere hours ago! These things are important to know, so people don't go around using bridge foot spreaders without understanding the situations that they should be used in.

A deeply arched belly may cause the bridge feet to separate more under string pressure than a flatter belly. And a higher arched bridge may be more flexible than a squatter one. But maybe not. That's where the luthier's skill comes in.

...and luthier experience. Does the Traeger book address bridge foot spreaders in this more discerning way? Or, does it prescribe bridge foot spreaders for all bridges?

-Trevor

 

[Ken McKay]

Sorry everyone, I should have not posted the comment It seems kind of odd that you, who apparently have... It just takes away from the information. My fault, I should have been polite and disagreed with the absolute statement that was made by fellesan (Branson Garner) FYI, there's no need to spread the legs apart when fitting. The string pressure doesn't cause the legs of a well-fitted bridge to spread.

I think we all agree that there CAN"T be a gap at the bridge feet edge. Not just for acoustical reasons, but because it is unprofessional. No luthier should feel comfortable, knowingly letting a bass bridge like that go out of his/her shop. I don't even consider the acoustical, mechanical, scientific stuff here. It just has to fit, no gaps!

By the way here is a photo from Upton's site showing the device in place, and it looks like the feet were already fit, but he left it in while thinning the top. Invalid Link Removed

I don't know if there is any reason not to use a spreader except if the spread caused a gap on the inside after it was removed, upon string pressure. But I don't see that happening when I use it. I use a spreader on all bass and cello bridges that I fit. Except when I install height adjusters.

Adjusters seem to have just enough play to allow the feet to rotate just enough so their is no gap. I could be wrong on this, and my absolute statement was arguable.

So Branson, are you saying that a well fit bridge won't spread? Or that an expert luthier will take into consideration the amount of spread when fitting the feet? Or something else?

 

[arnoldschnitzer]

I'm sorry for sounding like a know-it-all *******. It's what I do.

That's unfortunate. Opportunities for expanding your knowledge and experience multiply when you combine your curiosity with some humility. There is no need to be confrontational toward those with decades more experience than you. At the stage you are at with luthiery, your job is to learn, not lecture. I'm all for challenging the status quo, but first one needs a strong basis of knowledge and experience. To get there it is a good idea to try and keep ones ego in check. Not an easy thing to do...

 

[sonix]

thanks arnold.


no more comments please.

 

[Felessan]

That's unfortunate. Opportunities for expanding your knowledge and experience multiply when you combine your curiosity with some humility. There is no need to be confrontational toward those with decades more experience than you. At the stage you are at with luthiery, your job is to learn, not lecture. I'm all for challenging the status quo, but first one needs a strong basis of knowledge and experience. To get there it is a good idea to try and keep ones ego in check. Not an easy thing to do...

Thanks for that, I agree completely. It's something I struggle with. I'll try to err on the side of questions rather than answers from now on, unless specifically asked. I'm glad you acknowledge that "challenging the status quo" is important. It appears to me that sticking with tradition can be dangerous, but very useful to learn from.

Anyhoo, glad that all got worked out nicely.

-Trevor