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Three13

Bass bar question

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My girlfriend has a fairly well-made violin that sounds absolutely wonderful in the upper register, but is a little anemic on the low end. It has what I believe to be an unoriginal bass bar that is on the large/sloppy side that appears to have been put in when the top was regraduated (work that was allegedly done in the '60s or '70s). My admittedly amateur impression is that the top may have been closed before the bar was in its finished state. Some of old setup work on it was amateurish and was corrected, but having a bass bar worked on or replaced seems much more invasive.

I've read a few threads about bass bars here (the one Roger Hargrave started a few years ago was particularly interesting), and my takeaway is that nobody really knows how to optimize a bass bar; however, this one looks like it is far enough from normal that it could be an issue. I haven't been able to get a decent picture with the endoscope I have at home, or I would post it.

Any suggestions from members here who have dealt with an issue like this? 

Thanks!

 

 

 

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Cant help with the technical aspects, but never mess with a girlfriend's (or spouse's) violin.

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12 minutes ago, deans said:

Cant help with the technical aspects, but never mess with a girlfriend's (or spouse's) violin.

Wise words. She'll be making any and all decisions on this one...

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"Optomizing the bass bar" would be a bit tricky, since you can't really work on it while the violin is open, and you can't really tell what the results are until the violin is closed. What you "believe" may be a problem with the bass bar doesn't really mean much without real evidence. In any case, redoing the bass bar is an expensive experiment without guaranteed results. Any work that you go into with a luthier should reflect that it might not have the results that you're looking for.

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5 minutes ago, FiddleDoug said:

"Optomizing the bass bar" would be a bit tricky, since you can't really work on it while the violin is open, and you can't really tell what the results are until the violin is closed. What you "believe" may be a problem with the bass bar doesn't really mean much without real evidence. In any case, redoing the bass bar is an expensive experiment without guaranteed results. Any work that you go into with a luthier should reflect that it might not have the results that you're looking for.

This is exactly why I'm asking the question - it's major surgery based upon an educated guess. That being said, I had a very similar issue with a brace that was left unfinished in a pre-war Martin, and cutting it back to normal spec solved the problem.

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With the caveats that remote diagnosis is iffy, and I haven't found bass bar adjustments to have as much effect as you might think...

1) Is this a small-ish violin?  What are the dimensions?

2) If the bass bar is extraordinarily oversized and stiff, it should raise the B1+ resonance frequency slightly.  Is it at C# or higher?  

3) If you are uncertain about 2), you could record and post the sound of light taps on the side of the bridge (using a pencil or similar very light object) and it might show something with FFT analysis.

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Off the top of my head, it's a hair over 355-mm - I can measure when I get home. I'll also gladly try and record myself tapping on the bridge.

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It’s LOB is 357 mm - I’m not sure how to attach a sound file. Its tap tone on the bridge is a bit higher than the other violins that I have here.

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6 hours ago, Three13 said:

I've read a few threads about bass bars here (the one Roger Hargrave started a few years ago was particularly interesting), and my takeaway is that nobody really knows how to optimize a bass bar

There might be a lot of disagreement about the best way to make a bassbar, but it simply isn’t true that no one knows how to optimize one. Plenty of luthiers have made and currently do make livings doing just that. 

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The sound file took some converting so that Audacity could deal with it, but this is what came out:

FFT.jpg.672d9ad8f15b8f9b99123c4d950c994b.jpg

A0 at 275 Hz, B1- at 440 Hz are perfectly normal for a 4/4 violin... but the B1+ frequency at just over 600Hz looks extremely high... IF this remote analysis is accurate.  I wouldn't want to take drastic action based on this one somewhat questionable reading, but there is some evidence that you could have an extremely stiff bass bar.  

The bass bar won't have much effect on the A0 and B1- frequencies, but primarily influence the B1+ frequency.  

As a double-check, try recording a glissando on the A string in the low position (from ~B to F).  Maybe a couple of repeats of the glissando, and allow 3 seconds of dead time at the beginning of the recording to get past the advertisement that my freebie audio converter software overdubs at the beginning.  Or if you can record a .wav file, I could use that directly.

 

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Thanks! I’ll have to record that tomorrow, as I’m away from the fiddle till then. 

I’m really interested in learning a bit more about modes and what they indicate - is there anything out there that you’d recommend to a novice?

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14 minutes ago, Three13 said:

I’m really interested in learning a bit more about modes and what they indicate - is there anything out there that you’d recommend to a novice?

I would mostly recommend that a novice avoids getting into this stuff, as it is rarely useful (except in extreme cases, where this might be one), and usually is a distraction from what really matters.  However, if you MUST, try poking around in all the material Martin Schleske has on his site.

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7 hours ago, The Violin Beautiful said:

There might be a lot of disagreement about the best way to make a bassbar, but it simply isn’t true that no one knows how to optimize one. Plenty of luthiers have made and currently do make livings doing just that. 

And your point is?

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While it is possible that making changes to the bar might help if the regraduation was done by the same person who put in the bar then most likely the top is too thin which would usually give the sound qualities you describe.

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59 minutes ago, nathan slobodkin said:

While it is possible that making changes to the bar might help if the regraduation was done by the same person who put in the bar then most likely the top is too thin which would usually give the sound qualities you describe.

I have the opposite opinion.  

Three 13's violin symptoms indicate low output in the lower ranges.  A high bass bar and /or thick plates increases the frequencies and reduces the amplitudes of the lower resonances.  So I think the plates are still too thick and/or the bass bar is too high.

But as I was alluding to earlier, some different sound post positions should be tried first because those changes are reversible.

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While I agree that reversible (soundpost) adjustments seem like a good starting point, I wouldn't hold out much hope for that to be effective here.  The lower frequencies are large-scale body and plate modes, and moving around the soundpost a mm or two isn't going to do much for them. 

Secondly, if the readings are correct that the B1+ resonance is over 600 Hz (between D and D# on the low A string), then something is very far off of normal.  I have only seen that level on massively  thick factory-made German student fiddles... but then, the B1- and A0 frequencies have also been high on them, which is not the case here. 

The only logic that fits the information so far is that either the bass bar is extremely stiff, and/or the back crossgrain stiffness is extremely high... again, assuming that this one remote FFT analysis is not flawed.  Arching oddities could also have some effect here (high arch top, flat-sh back), but that seems unlikely to me.

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6 hours ago, Marty Kasprzyk said:

Where is the sound post positioned relative to the bridge foot?

2.5-mm south of the edge of the bridge. It's been moved around without a huge difference in tone.

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6 hours ago, nathan slobodkin said:

And your point is?

My point is that one should not assume that the bassbar is unimportant or has little effect because some people who haven’t been able to make good bars have given up and declared it impossible.

I don’t think the bar is really such a mysterious thing, but I certainly don’t think it’s unimportant. If that were the case, it would’ve been redesigned or changed out for something else long ago.

As far as the OP’s question is concerned, I’d leave the original bar alone or put a new one in rather than adjusting the existing one. It’s just too much of a hassle to do the work and glue it back together, just to find that something should have been done differently and the top has to come back off to fix it. If I make a new bar I can be in control of more variables. 

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5 hours ago, Marty Kasprzyk said:

I have the opposite opinion.  

Three 13's violin symptoms indicate low output in the lower ranges.  A high bass bar and /or thick plates increases the frequencies and reduces the amplitudes of the lower resonances.  So I think the plates are still too thick and/or the bass bar is too high.

But as I was alluding to earlier, some different sound post positions should be tried first because those changes are reversible.

I was thinking "anemic" meant hollow sounding. If simply a lower output of sound I am sure you are right.

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13 hours ago, Don Noon said:

The sound file took some converting so that Audacity could deal with it, but this is what came out:

FFT.jpg.672d9ad8f15b8f9b99123c4d950c994b.jpg

A0 at 275 Hz, B1- at 440 Hz are perfectly normal for a 4/4 violin... but the B1+ frequency at just over 600Hz looks extremely high... IF this remote analysis is accurate.  I wouldn't want to take drastic action based on this one somewhat questionable reading, but there is some evidence that you could have an extremely stiff bass bar.  

The bass bar won't have much effect on the A0 and B1- frequencies, but primarily influence the B1+ frequency.  

As a double-check, try recording a glissando on the A string in the low position (from ~B to F).  Maybe a couple of repeats of the glissando, and allow 3 seconds of dead time at the beginning of the recording to get past the advertisement that my freebie audio converter software overdubs at the beginning.  Or if you can record a .wav file, I could use that directly.

 

Sound file? Is there a recording on the OP's post somewhere?

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And just maybe it's not the bass bar at all.  There are a number of things that can be done with adjustment that can improve the lower register of an instrument, but the instrument has to be physically sound to begin with.  Purfling openings, loose peg ornaments that cannot even be heard as buzzes or seams that are only open on the inside, especially in the upper and lower block areas of the top, can really mess with the sound of an instrument.  People are responding to the question you asked, but there might be other questions that should be answered first.  Best of luck with it!

 

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1 minute ago, nathan slobodkin said:

I was thinking "anemic" meant hollow sounding. If simply a lower output of sound I am sure you are right.

The OP has been emailing me files recorded on the phone, which I have converted to .wav files for Audacity.  From the glissando recording, to me it sounds very clear and bright, perhaps overpowering the low end.  Here's an MP3 version of it:

Home 2.mp3

The FFT of the above:

1558420342_Astringglissando.jpg.f5911e50e77f65d9683dc817b5af194d.jpg

Since this is only the A string, there is no A0 resonance peak.  Now the B1+ shows to be a more reasonable 554 Hz, and the B1- peak is 458 Hz.  These seem slightly on the high side for 357 LOB violin, but not really abnormal.  There's a $16 million Guarneri out there with MUCH higher resonances.

There are two basic factors that determine resonant frequencies... stiffness and mass.  You can have an instrument that is heavy, but extremely stiff, and it can have the same frequencies as one that is normal stiffness, but light.  Or anything inbetween.  To get a possible clue, try weighing the violin without the chinrest.  

My personal experience is that a violin with dense, strong wood works better when it's thinner and the resonant frequencies are lower than normal, and light wood works better thicker and with higher body frequencies.  The dense wood instrument is still heavier, though.

 

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