Low mass bridge / dense body

[bloke_zero]

So I was thinking about that neck dead spot thing, where the neck will create dead spots where its resonances will interfere with certain frequencies. Putting the neck out of the picture for a minute, I'm thinking that in some ways the best combination might be to have a dense body with a very stiff low mass bridge anchored firmly to body, that way the string would be free to vibrate without fighting resonances in the body? Obviously you'd want a really stiff neck too.

[itu]

Ned Steinberger tried to reduce dead spots in the late 70's or early 80's. He started to remove material from the tuner end, so the headstock. The more he took away, the higher the dead spots rose. "Now here I have this black instrument..."

From materials point of view the existing ones are just fine. Some shapes have an effect on the response. CF is a nice material because it is light and so stiff.

Some notes:

- the instrument has to have some mass to fight against the movement of the string

- the instrument has to be stiff so that it does not lose the vibrations to the body and neck deformations

- there are resonances in the instrument that can be harmful against the amount of vibration (in other words, there is some dampening because of the shapes)

What else...

Edited November 3, 2020 by itu

[bloke_zero]

Yes - I was thinking of Steinberger and the resin bodies - seemed like an interesting trade off - higher density material to offset the smaller body. 

9 hours ago, itu said:

Some shapes have an effect on the response.

Can you point me in the direction of any literature on that point?

 

9 hours ago, itu said:

CF is a nice material because it is light and so stiff.

I see gotoh do a CF bridge - seems like a nice pairing with a status neck.

[DiMarco]

I have had dead spots on basses with really dense body woods so there's no guarantee. Higher/ lower mass bridges can both help when a dead spot exists but I do not think either can be considered better then the other in that scenario.

Resonant frequencies and standing waves depend on everything in the instrument that vibrates. Adding or substracting any mass will impact this but you can't rely on any of it to eliminate the possibility of dead spots occuring as resonance is the sum of many things.

 

 

Edited November 4, 2020 by DiMarco

[bloke_zero]

6 minutes ago, DiMarco said:

Resonant frequencies and standing waves depend on everything in the instrument that vibrates. Adding or substracting any mass will impact this but you can't rely on any of it to eliminate the possibility of dead spots occuring as resonance is the sum of many things.

Yes I understand - I think one of the fascinations of instruments is exactly this "sum of many things" thing, and coming to a balance between a technical understanding and acceptance that some of it is art not science.

I'm just trying to get a clearer understanding of the factors and their weighting. I have a roasted maple neck with graphite stiffeners that I feel really helps the instrument sing. I'm about to experiment with a more trad maple p-bass neck on a different build.  My feeling is that the neck is going to be the key part, but I'm trying to get a feeling for how the whole is going to interact.

One of my drivers is getting a feel for how different body materials will perform especially if you keep them more part of the equation by not using a highmass bridge.

[Beedster]

It would be rather amusing if this line of thinking led to a trend for low mass bridges given discussions elsewhere on the forum

[Beedster]

Wooden instruments are like human beings, there are general rules but while most instruments conform to some, very very few if any conform to all, and some even conform to zero! Trial and error with each individual instrument is the only way

[bloke_zero]

2 minutes ago, Beedster said:

It would be rather amusing if this line of thinking led to a trend for low mass bridges given discussions elsewhere on the forum

I agree 🙂 - but it'll never happen!

1 minute ago, Beedster said:

Wooden instruments are like human beings, there are general rules but while most instruments conform to some, very very few if any conform to all, and some even conform to zero! Trial and error with each individual instrument is the only way

It's the spirit of enquiry! I think this is why high mass bridges are attractive as they remove some of the vaguaries of the wooden element. At the moment I'm trying to work out what I like the idea of better, and make a guess at the outcomes.

I'm currently looking at a maple neck with a hard dense northern ash body and stiff low mass bridge, which I'm thinking will (probably maybe!) provide a bright but pretty rigid basis for experimenting with pickups.

[BigRedX]

14 minutes ago, bloke_zero said:

It's the spirit of enquiry! I think this is why high mass bridges are attractive as they remove some of the vaguaries of the wooden element. At the moment I'm trying to work out what I like the idea of better, and make a guess at the outcomes.

Unfortunately if you consider the physics behind it, you realise that high mass bridges don't work because they are high mass (the additional weight they add to the body is pretty much negligible when compared with the total body weight of the bass), but because they are better engineered than the standard BBOT bridge in reducing lateral movement of the saddles. 

[Beedster]

6 minutes ago, BigRedX said:

Unfortunately if you consider the physics behind it, you realise that high mass bridges don't work because they are high mass (the additional weight they add to the body is pretty much negligible when compared with the total body weight of the bass), but because they are better engineered than the standard BBOT bridge in reducing lateral movement of the saddles. 

That's if they do work

But yes, agreed, most HMBs are simply more stable, although as someone who mostly plays heavy flats, I find that the sheer mass and tension of the stings tends to keep even the lightest of bridges in it's place

[itu]

1 hour ago, bloke_zero said:

Can you point me in the direction of any literature on that point?

You can start from any acoustics book available from the libraries. The maths behind some basic shapes is nearly easy. But, when you start to analyze some more complicated shapes made of wood, which is not uniform, you may have a very strange set of calculations. Chladni patterns (see YT) may interest you.

The science of sound is one very basic book made by Tom Rossing.

[PaulThePlug]

https://g-gotoh.com/product/cbt-01/?lang=en

Carbon Fiber Machine Heads - Esential Bling for ya Status Neck n bridge... £Kerching

Edited November 4, 2020 by PaulThePlug

[bloke_zero]

4 hours ago, itu said:

The science of sound is one very basic book made by Tom Rossing.

Thanks - I'll check it out.

 

3 hours ago, PaulThePlug said:

Carbon Fiber Machine Heads - Esential Bling for ya Status Neck n bridge... £Kerching

Yeah - I was thinking with all this talk of high mass is why are gotoh and KTS selling low mass stuff for so much money - where is the HYPE!?

https://www.k-t-s.com/en/products/bass.php

But seriously I was interested in another approach that wasn't brass/highmass as I got a bass body that had hipshot aluminium bridge on it and it got me thinking about the whole subject, and why it might be that some people felt that the old style Fender bent L bridge sounded better.

[DiMarco]

5 hours ago, bloke_zero said:

I'm just trying to get a clearer understanding of the factors and their weighting. I have a roasted maple neck with graphite stiffeners that I feel really helps the instrument sing. I'm about to experiment with a more trad maple p-bass neck on a different build.  My feeling is that the neck is going to be the key part, but I'm trying to get a feeling for how the whole is going to interact.

 

For sure this has a lot of impact. The strings will ring out longer and the colouration of tone changes too if the neck is more sturdy. At least if I can judge from the differences in tonal character I hear between my Fodera Jazz (maple neck, ash body) and the Zon Sonus (carbon neck, ash body) which are both 34" and have the same strings and pickup config. The all wooden Fodera sounds warmer and gels better inside mixes while the Zon sounds ultra articulate and snappy. This occurs both acoustically and amplified. I strongly believe the neck plays a huge part in these different sound qualities.

 

[itu]

Again, back to basics:

If the string was bolted to a rock (not vibrating base), you should be able to transfer the string's vibrations to a pickup in its nakedness. The rock won't move at all. There is also the possibility to check how the magnets affect the strings.

Now if the string is put to a massive plate (piano, anyone), the plate's mass is tuned very low. It should not affect the vibration very much, but ONLY IF the plate is stiff (not like dough).

Let's reduce the instrument weight from 500 lbs to under 10 lbs. Now the neck shape (every shape has its own frequency, if the stiffness enables it) and weight (including frets, tuners etc.) may turn to a vibrating element just like the body. The difference to the piano (heavy) example is that the frequency has risen substantially and may be in the audible area = resonance = dead notes.

Edited November 4, 2020 by itu

[Steve Browning]

20 hours ago, Beedster said:

That's if they do work

But yes, agreed, most HMBs are simply more stable, although as someone who mostly plays heavy flats, I find that the sheer mass and tension of the stings tends to keep even the lightest of bridges in it's place

This is very true. On the one hand, I have always replaced the bbot bridge on my basses with the Gotoh 203 bridge but, on the other, that's more to do with the theoretical additional stability of the grub screw tracks rather than any actual dis-satisfaction with the original bridge.

[bloke_zero]

14 hours ago, itu said:

Let's reduce the instrument weight from 500 lbs to under 10 lbs. Now the neck shape (every shape has its own frequency, if the stiffness enables it) and weight (including frets, tuners etc.) may turn to a vibrating element just like the body. The difference to the piano (heavy) example is that the frequency has risen substantially and may be in the audible area = resonance = dead notes.

I don't think anyone is arguing against that: more referencing the bewildering number of factors that come into play. And that there is  more to the sitaution than just the stability of the materials and resonance but also how the character of the material impacts the character of the sound.

[itu]

2 minutes ago, bloke_zero said:

...there is more to the situation than just the stability of the materials and resonance but also how the character of the material impacts the character of the sound.

This "character" is exactly about the stiffness and uniformity of the wood. The shape plays a role because as I wrote earlier, the shape has a "character", too. This is one lovely video: https://www.youtube.com/watch?v=OLNFrxgMJ6E

The "character" of the sound is directly related to the vibrations affected by the material. Shape of the neck is another. The connection (placement, tightness etc.) between that body and the neck is again one more thing that affects the tuning of the whole system. There are details that usually do not affect the complete picture, but they can ruin the overall sound, too. Just think about a loose bridge saddle.

I do want to remind you all, that as the body is pretty thick and heavy (and hopefully stiff, too), it tends to play smaller role than that thin rod named as neck.

[mybass]

Fender bass bridges are near the end of the body and I remember talking about topic this years ago with another bass builder and tapping an unloaded Fender type body where the bridge is usually placed, it sounded 'lighter/hollow' as opposed to tapping the body more or less where the precision pickup would go, where it sounded quite different, more 'solid'. So possibly a Gibson guitar or (Les Paul type) bass has the bridge in the best 'area' of body wood while Fender type bridge placements dont take advantage of the best area to mount a bridge.......maybe leading to the idea of the high mass bridge to help overcome this.

Edited November 5, 2020 by mybass

[itu]

On 04/11/2020 at 12:05, bloke_zero said:

One of my drivers is getting a feel for how different body materials will perform especially if you keep them more part of the equation by not using a highmass bridge.

Have you been considering making the bridge from the same body wood? Testing the material would be pretty easy, and the part wouldn't have to be too precise. The main point was simply to test the difference, wasn't it.

Actually most of the bridges do perform very well and in a similar way. There are features (top loading, colours, size...) and exotic designs, but the main idea is to anchor the strings firmly to the other end of the body. But if the weight differs from another, it means that the body-bridge system has a different tuning. Try with a metal tube or plate and attach magnets one by one to the other end. Feels and sounds different, doesn't it?

[bloke_zero]

27 minutes ago, itu said:

Have you been considering making the bridge from the same body wood? Testing the material would be pretty easy, and the part wouldn't have to be too precise. The main point was simply to test the difference, wasn't it.

You're making me think that instead of endless "research" on the internet I should build a workshop and do the experiments rather than gathering opinions!

[ikay]

Here's a vid comparing bridges made from wood and metal. As he says, far too many variables between the basses for this to be a scientific comparison but interesting nevertheless. The wooden bridge has a fuller and much more balanced sound to my ears. Hmm, I'm tempted to do a bit of experimenting myself!

 

Edited November 6, 2020 by ikay

[bloke_zero]

Great video! I think he's referencing the acoustic properties of the bass and how it feels when played and then hearing how little that effects the actual sound through the pickups.

I can hear some differences - it feels like slightly extended bass and dropped mids in the first two. But the finger style lick at the end sounds pretty much identical to me.