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Deep science required here...

billoetjen

billoetjen

May 3, 2005
1,291
21
Burlington, Vermont vt
#1
I've noticed that a lot of mighty fine basses (only among 4 or 5 string, I never look at anything more extreme) tend towards either quite massive one-piece bridges or minimalist individual monorail types. Not all - but a lot of them.
The philosophy in support of massive bridges (MB's from now on) seems to go like this:
high mass allows the string to retain more of its energy, yields longer sustain, more punch, whatever.

Minimalist, individual monorail types (monorail, from now on) allow the body wood to absorb some of the energy and contribute to the sound -yada yada yada.

Like I said, some damn fine basses are made with both of these. Yet the theory behind them appears to be inherently contradictory. What gives? Lotsa smart people on TB. Is this all a bunch of malarkey? Could I just as easily drive a few well-placed nails into the end of my bass and save myself some dough? :rolleyes:

There's a reason for this post, you know. I am waiting for some carefully chosen (and hopefully, assembled) parts from Warmoth that will be the chassis for my new bass. I got lots of other components figured out (I think) but can't decide on which end of the bridge spectrum to commit to. Already have a brass ABM from eBay. But I'm almost tempted to get some light monorails and bolt them through the body to a single steel plate located on the back. I'm not kidding. Gets the tone wood (whatever that is) into the act, and grounds them all together. I can't use string-through, though, because the strings I use are too heavy/tense (Labella DTB medium flats). By the way, since the Warmoth neck is going to be heavy, the ABM will help balance it, right?
Bill Oetjen
[email protected]
 
#2
Stringing through the body will not effect the tension. At all.

Your string can continue on for miles past the bridge, and it won't change the tension, tone, pitch, mojo, or awesomeness. It might make your bass hard to play, though.
 
#3
What you plan to do existed in the past. It wa called the 2tek bridge. Pretty hard to find though.
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The Hipshot Triple-Lock would make your project pretty easy.
[Invalid or Expired Link Removed]
 
#4
I know I should stay out of this but I can't resist. My feeling is that sustain is a complex issue and that what most people are really after is to get more sustain of the fundamental. In other words you want to avoid your tone wandering up into the harmonics as it sustains. And to a large extent this is a product of neck materials based on experiments performed by the Wickershams.

In any case, sustain in general is highly overrated. How often does a bass player need a note to sustain for more than 3 or 4 seconds? And you can have a huge increase in sustain just by playing with a lighter touch and turning up your valve tubes ;)

On another note (npi) note that the Hipshot triple-locks do require milling. The bottoms are not flat to be screwed onto the top surface of the instrument. There's a segment sticking down that's about an inch long and .250 deep that needs to be milled for.
- SoM


Edit:
Milling for Hipshots...
Link Removed
 
#5
Start with the fact that no one I'm aware of does any finite element vibratory analysis to predict the effects of bridge designs and materials on string vibration.

Add to this the idea that there is no objective definition of good tone (quite the contrary, it's very subjective), or even of what different people may mean by the words sustain, tone, punch, bite, etc. So even if there's a defined target for each individual person, there's likely to be a lot of miscommunication between people.

What you're left with is people's anecdotal descriptions of their experiences. Some of those may be insightful, drawn from broad experience, and of use; probably very many are highly colored by the person's expectations as much as by the actual results.

In my opinion.


More fact-wise, more mass at the string terminus should result in more of the energy being reflected back into the string, rather than transmitted to the body. But I wouldn't even necessarily equate that with "more sustain," because a) you're only accounting for one of the two ends of the vibrating string, and b) sometimes a body resonance could contribute to a longer sustain, and the bridge might be serving to isolate the string from the body, and c) the design of the bridge could have at least as much to do with the sustain as the mass does, due to stiffness considerations.


In my opinion there's a lot of science being strangled and killed while being forced into a yoke in service of marketing, in many areas of musical instrument commerce.
 
#6
i you cant see me from there Im
sitting here and pointing at my nose/

(translation is the above it pretty accurate)

I'd like to add the fundamental vibration FR and amp
are lexicon to energy absorbtion/conduction the end game is tone and sound.
which I think the problem lieis withing the fact that musicians on AVERAGE arent scientists or physicists and dont knwo how to articulate what Excatly they are looking for in sound!
theres
Woods (hehe)
scale.
the pups, pre, and the metallic features to all consider and to get any of the above to boil down to a musicians onamonopea
wah wah wah wahhhhhhhhhhhhhhh :(
is redicule as le french say.


In summation:
I wouldnt make that kind of emphasis on energy transferrance unless you are sure this one variable in a sea of variables will be most noticeable.

I have sunken high mass brass bridges and hipshot A's
and I think the finish on the instrument has most effect.
but for very low mass bridges like cheap barrel bridges there may be a detrimental effect because there must be a mass/energy point that transferrance is lost at an accelerated due to small mass. and that quotient must be at a easier point to achieve than the addition of high vibration/energy conductance mass to the intrument.
Remember you still have to shoulder this beast eventually!

oh yea that sushi pic for the new supporting members avatar is calling me.
Gotta go!!!
 
#8
Ok, well here's another way to think about it, daimb... It's like building a fast car. There are a lot of variables, and a lot of things that can improve it, and a lot of things that can't be reliably controlled. When you build an instrument you do your best to control all the important factors, and if you're good at all of them on average your instruments will kick ass.

But there's no one thing that you can do to an instrument, that by itself will necessarily hop it up. Like you can't just put a 3" exhaust on a civic to get more horsepower (or a '64 Nova).

Ok, I'll just shut myself off now...
 
#9
Hi,
about the string-through question - here's a link to the "Just Strings" page on LaBella DTB flats

Link Removed

It says flat out that these strings (my current favorite) should not be used string-through. I may have over-stepped by suggesting that that prohibition was because of their unusually high tension. I just informally corellated the two facts, and figured that they were related. Maybe someone else has a better-informed opinion on why.
Bill
 
#12
Angus said:
...are you sure? :hiding:
Click to expand...
I'm sure that, like I said, I'm not aware of anyone doing it. (You had stated an intention to do real-world testing, but I haven't heard anything on that.) Do you have anything interesting going on? It seems to me that you'd have to analyze the whole instrument, or at least make a pretty good/valid response map/assumption/function for the rest of the body/neck/instrument/string first, in order to get anything useful out of a bridge analysis.




My guess about not using the labella flats on a string-through is that either the harsh break angle might screw up the wraps too much, or the winding length is not long enough to reach the nut properly if started halfway through the body. Just guesses.
 
#18
As I'd hoped - a lively if sometimes convoluted discussion. Unfortunately, I don't feel like I know any more now than I did when I posted the question, except that TB'ers can be really entertaining.

Thanks for listening and contributing. When the neck and body pieces arrive on Tuesday, I'll start the process of finishing it. The ABM is destined to hold down strings at one end; Hipshot ultralites at the other end. Ultimately the tone depends on these (holding up ten fingers).
Bill
 
#19
Again, what does the bridge do? It:
- defines the tonal length of the string
- it connects the string to the body

What we can see, immediately, is that the fixation, i.e. the ability to be still, will influence the performance. This ability is a function of design and material stiffness (weight is a resulting parameter).

Combine the above with the fact that any vibrational response is a function of the distribution of stiffness and mass in the vibrating body. "In", since it is about a three-dimensional distribution. And then we need to add excitation and external damping (fingers, pickups, belly...) into the equation...

Generally, we can say that higher mass on further distance from eachother should result in lower natural frequences. But in a complex mechanical system as string instrument, there are so many parameters to modify, that you are way deep whatever you try.

Sustain, i.e. the time from excitation to rest, is mostly due to how much of the string harmonics that are lower than the lowest harmonic of the carrier. An extermely light and stiff instrument would have the best sustain, by having only very high resonance frequencies which will not counteract the lower string freq's.

All this is a qualitative discussion over some (only some) of the parameters that influence the performance of your intrument.
I am not aware of any research that proves its correctness in our favourite application, nor have I seen anything that points in any other direction.
What I know, is that I have seen results of one FEA modal analysis of a guitar, and that they support the above, and adds one more input: the majority of vibration modes are...torsional.

You can analyse to death. And/or you can make great instruments.
I prefer making instruments that consist of the basics, strings and a neck, and a few (or little) other disturbing factors as possible. But for reaons of aesthetics, loudness and conveniance, I regularly add body, electronics, tuners and similar ...
 

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