Jump to content
Maestronet Forums

Bridge tuning question


Goran74
 Share

Recommended Posts

There is too much noise about bridge tuning. I have little experience so it is not clear what has sense and what does not. I have read almost all the research papers. Also I found that http://www.violinresearch.com .

Which are the rules of violin tuning in the end? Is it a so complex process that needs a scientific laboratory for research or it is a matter of following simple rules?

Thank you all

Link to comment
Share on other sites

17 minutes ago, Goran74 said:

There is too much noise about bridge tuning. I have little experience so it is not clear what has sense and what does not. I have read almost all the research papers. Also I found that http://www.violinresearch.com .

Which are the rules of violin tuning in the end? Is it a so complex process that needs a scientific laboratory for research or it is a matter of following simple rules?

Thank you all

I don't think that http://www.violinresearch.com  Is a very good resource. For instance, I don't know of any highly successful maker or adjuster who "tunes the pegs" .

I do know of such people who "tune" bridges, but not using methods like he illustrates.

Link to comment
Share on other sites

1 hour ago, Goran74 said:

There is too much noise about bridge tuning. I have little experience so it is not clear what has sense and what does not. I have read almost all the research papers. Also I found that http://www.violinresearch.com .

Which are the rules of violin tuning in the end? Is it a so complex process that needs a scientific laboratory for research or it is a matter of following simple rules?

Thank you all

Making  bridges is an art for itself. In my opinion there won't be a difference between "tuned" and "non-tuned" bridges, but there will be a huge difference between good and bad bridges. I strongly recommend the article of Jerry Pasewicz's shop about bridge carving - it is a great resource.

Link to comment
Share on other sites

There's something a bit ironic about asking on the internet for folks to sort out all the chaos that one finds on the internet.

You need to determine for yourself who knows what they're talking about and/or gets consistent good results.  Crackpots tend to have more motivation to expound upon their fabulous theories; the experienced pros just get things done, but if you know who they are, sometimes you can pick up a thing or two.

Link to comment
Share on other sites

18 minutes ago, Don Noon said:

There's something a bit ironic about asking on the internet for folks to sort out all the chaos that one finds on the internet.

You need to determine for yourself who knows what they're talking about and/or gets consistent good results.  Crackpots tend to have more motivation to expound upon their fabulous theories; the experienced pros just get things done, but if you know who they are, sometimes you can pick up a thing or two.

I agree with you. You are right. Thank you all for your answers and your time. Of course as I said I am not experienced and that is why I ask. There is chaos at the internet. Because of that - forums like maestronet come to resolve that issue.

Link to comment
Share on other sites

1 hour ago, Don Noon said:

There's something a bit ironic about asking on the internet for folks to sort out all the chaos that one finds on the internet.

You need to determine for yourself who knows what they're talking about and/or gets consistent good results.  Crackpots tend to have more motivation to expound upon their fabulous theories; the experienced pros just get things done, but if you know who they are, sometimes you can pick up a thing or two.

That’s great. Got a big smile from me.

Link to comment
Share on other sites

4 hours ago, Goran74 said:

There is too much noise about bridge tuning. I have little experience so it is not clear what has sense and what does not. I have read almost all the research papers. Also I found that http://www.violinresearch.com .

Which are the rules of violin tuning in the end? Is it a so complex process that needs a scientific laboratory for research or it is a matter of following simple rules?

Thank you all

Cutting bridges well takes a lot of skill, which takes some time to develop. There are good tutorials to get you started and give you enough understanding to cut a bridge. Doing it over and over and having your work critiqued by other workmen and by players is really the best way to take your skills to a higher level and develop a sense of personal style.

As far as tuning goes, there was an interesting experiment conducted at the VSA’s workshop at Oberlin a while back. Some skilled makers and acousticians worked together to test ideas and measure their own bridges. The aim was to discover what made the most difference to the sound. If you’ve seen one of Joseph Curtin’s lightweight bridges, they are related to that testing—everything that could be removed without ruining the sound was carved away, leaving what was considered the minimum material necessary for strength and tone production.

If you want to try tuning, you can get a quick start by setting up a good microphone close to the bridge and tapping it with a firm object (like a pencil), and recording the tap with software like Audacity.  Make sure the taps are as consistent as possible and that your microphone position is the same for all tests. To interpret the data, you can find several papers in the VSA journal or some discussions here on Maestronet; however, you’ll find that interpreting what you record can easily become a rabbit hole.

To some extent it depends on your personal beliefs: given all the available information, you can either make working on bridges as straightforward or as complicated as you desire.

Link to comment
Share on other sites

14 hours ago, The Violin Beautiful said:

you want to try tuning, you can get a quick start by setting up a good microphone close to the bridge and tapping it with a firm object (like a pencil), and recording the tap with software like Audacity. 

Thank you for your information. With so many information around, it is difficult to find the end of the procedure - and the most of the time I overdo things. This is the reason why I want to declare the limits. This method with the microphone (I read Curtin's article and the Maestronet's references) does it have better results with a piezo sensor (like Curtin's)? I never tried that but I plan to do it. Of course I need a jig to hold the feets I guess.

Link to comment
Share on other sites

1 hour ago, Goran74 said:

This method with the microphone (I read Curtin's article and the Maestronet's references) does it have better results with a piezo sensor (like Curtin's)? I never tried that but I plan to do it. Of course I need a jig to hold the feets I guess.

I've mostly used a piezo strip, but after Don Noon said that a cheap little lapel microphone works fine, I tried it and it does, plugging right into the microphone port on  a computer. A piezo strip will require the purchase of a jack, and some soldering and wiring, and maybe running the signal through a preamp. I actually think the little microphone works better.

For the "rocking mode", you'll be looking for a peak around 2400 to 3200 hz.

Link to comment
Share on other sites

It's quite easy to measure the "base" frequency of a bridge blank

http://www.thestradsound.com/ongoing/tuningthebridge

What you get is some info on how stiff the bridge is compared to weight. The frequency is sensitive  to outline dimensions, so it's a good idea to do the height/width first, before you start with thickness and other cuts

 

Link to comment
Share on other sites

20 minutes ago, Peter K-G said:

It's quite easy to measure the "base" frequency of a bridge blank

Thank you Peter. As I can see, in this  process is used a tablet, an application (which apk?), and the method is: throwing the bridge from a standard height on a hard surface and recording the frequencies?

Link to comment
Share on other sites

26 minutes ago, Goran74 said:

Thank you Peter. As I can see, in this  process is used a tablet, an application (which apk?), and the method is: throwing the bridge from a standard height on a hard surface and recording the frequencies?

I  just dangle the bridge with a thread in front of the mic and tap it with a nail.

The software is for IPad/IPhone  Studio Six Digital - audiotools

https://www.studiosixdigital.com/audiotools-modules-2/

Link to comment
Share on other sites

I normally use SpectraPlus because it's what I'm most accustomed to (and because it offers so many different functions and views), but the Audacity freeware will work fine for this.

Most of us are clamping the feet in a vise to take the "rocking frequency" measurement, believing that this mode is the most important. Peter's measurement is probably picking up a different mode (a forward and back motion rather than side-to-side), so his measurements would not cross-reference with those from the "general practice" regimen.

Link to comment
Share on other sites

39 minutes ago, David Burgess said:

I normally use SpectraPlus because it's what I'm most accustomed to (and because it offers so many different functions and views), but the Audacity freeware will work fine for this.

Most of us are clamping the feet in a vise to take the "rocking frequency" measurement, believing that this mode is the most important. Peter's measurement is probably picking up a different mode (a forward and back motion rather than side-to-side), so his measurements would not cross-reference with those from the "general practice" regimen.

Yes,

The mode I'm measuring is the same you hear when you drop a bridge and it's bouncing on a hard surface. I also choose bridge blanks to start with from that. Some are low ringing and they are not very stiff, If I would choose such a blank I would need to make them thicker than usual to get it ~3000 Hz. Interesting is that this frequency is about the same as the ala Curtin measuring (I have read his papers many times)

Link to comment
Share on other sites

53 minutes ago, Peter K-G said:

Yes,

The mode I'm measuring is the same you hear when you drop a bridge and it's bouncing on a hard surface. I also choose bridge blanks to start with from that. Some are low ringing and they are not very stiff, If I would choose such a blank I would need to make them thicker than usual to get it ~3000 Hz. Interesting is that this frequency is about the same as the ala Curtin measuring (I have read his papers many times)

The two modes aren't far apart in frequency. The same bridge blank gave me a measurement of 2567 (your method, free bending mode) and 1930 (rocking mode).

Curtin"s data is from the rocking mode with the feet fixed, although he and others at the Oberlin Acoustics workshop have probably taken measurements of several other modes too at one time or another in an effort to figure out which does what to the sound, and what might be most useful.

Link to comment
Share on other sites

I have Curtin's article printed, but it's still online:

https://josephcurtinstudios.com/wp-content/uploads/2017/06/bridge_tuning.pdf

Did try to measure this rocking mode about the time the article was published (2005) but I didn't have good enough software and mic. I should give it another try sometimes and compare with the "ring" mode.

Thanks

 

 

 

Link to comment
Share on other sites

3 hours ago, Goran74 said:

Do I have to tap the bridge in any special way or with any special tool? Thanks

You need a small vise to hold the bridge feet, and something very light to tap the side of the bridge with.  The moving mass of the bridge is not much (~1g), so you should use a "hammer" of that mass or less to avoid double-contacts.  Something heavier might work... but not as well.

And a microphone that you can get very close to the edge of the bridge.  Something small.

 

As for the fore/aft bending, or free-free mode frequencies, I see that as being too far removed from anything that actually happens on the instrument to be anything other than (perhaps) a quick way to initially sort out stiff from less stiff bridges.  But the dimensions of the bridge, particularly thickness, have a huge influence, and can easily mask any differences in the contributions of the wood properties.  I don't bother with it.

Link to comment
Share on other sites

3 hours ago, Goran74 said:

Thank you Peter. As I can see, in this  process is used a tablet, an application (which apk?), and the method is: throwing the bridge from a standard height on a hard surface and recording the frequencies?

Another way of measuring bridge frequencies is by bowing over the clamped bridge. Its best to start at a corner with a rather high bowing pressure.

Link to comment
Share on other sites

Tuning schmooning, I find this to be a psychosomatic insistence on hearing an improvement, not saying that an improvement can't be heard from  altering the bridge, but  I'd be much more inclined to blame any improvements on the change in the mass of the bridge, not any frequency changes from its stand alone frequency 

Once the bridge has been compressed , it has in essence been coupled or joined with both the strings and the top and at that point is no longer the same independent part anyway,

Tuning imo , in general ,is a waste of time that yields no better results than "guessing" and that if you "tuned" something and it sounds better it's most likely because you altered the mass, the frequency is simply a by product of the mass.

I see no correlation between constructive or deconstructive frequency interactions of the entire violin by altering frequency of individual components, again not saying that it does nothing, just saying that it is not a predictable repeatable "improvement" that warrants the wasted time of going through it all.

If you do this thing "luthier" it seems almost guaranteed that you will at some point "mess" with tuning as there is much talk about it, but I think most of us that "mess" with it, in the long run find it "neato" but pretty useless , something that may glean some information, but all in all something that really just slows production down and takes away from the process of intuition, which I find much more valuable than anything that is  'measurable"  

if you want to build great sounding instruments the best thing you can do is build as many of them as you can

Link to comment
Share on other sites

I think you would make quicker progress by taking the approach of trying to find out how specific changes in bridge construction affect tonal properties of the violin.  For instance, an easy place to start: the thicker you leave the top edge, the more higher frequencies are muted (much like putting a mute on). As you thin the sound becomes brighter, and simultaneously noisier. On many violins there's a sweet spot when you have the maximum of "good" brightness, before the sound starts adding just high frequency noise. 

Having a catalog of such changes that you can apply to a specific violin as needed is a much more useful strategy that attempting to tune a bridge to some specific frequency, which may or may not accomplish anything you need on a specific violin. The best way to learn this is to do it yourself, so that you learn to hear what's going on, what's missing from a violiin, how to add that or subtract things you don't like, rather than relying on other peoples' descriptions.

Bridge adjustments are the same as any other change you make to a violin: a path to something different, not a one-stop cure-all.

Link to comment
Share on other sites

Amati, Guaneri, and Stradivari managed to make divine instruments without peizo sensors, and probably without a rigorous understanding of of mode patterns.  I try to do the same - perhaps because I am a happy Luddite.

I find that careful plate thicknessing and careful bass bar contouring consistently yields a rich tone and good responsiveness in all positions.  I don't bother with tuning.  Your time is better spent understanding sound post adjustment.

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.


×
×
  • Create New...