Violin Forum/Message Board

[jethro]

Monkeying with different bridge and soundpost combinations after
putting on new dominant strings (violinos before)
I have been having a chronic problem on the A string mainly but a little
on D and E too. When I bow lightly the string wants to "Ring at a much
higher tone about A5 instead of the open string Freq of A4.
I think this is either a bridge or soundpost problem. I have gotten it to
be less by moving the post and bridge arround but there seems to be still
some I can't get rid of. It kind of prevents playing a very pianno note.
It also slightly "prevents" the fundimental from starting- kind of makes a
lack of immediacy to the attack of the notes. Hard to start the note.
I have very thin ankles on the bridge from the Violino strings. Could these
be allowing too high pich vibration through the bridge and raising the "Q"
for the super high frequencys ?

I have run out of adjusting ideas - please give me guideance !
Tim

[Jack Rushing]

First, I would give the new Dominants time to break-in, before moving the
sound post around, or trying a different bridge. It usually takes me about
a week of playing, to get them to sound right, especially on the A&D strings.

A thin ankle bridge might be best for the low tension Violinos, but I dunno
about the Dominants.

I use a bit thicker bridge and feet for my Dominant set ups, and find that it
helps a lot to have the string width at the bridge 34mms, instead of 35mms
or over. Of course, this is just my opinion, and different violins call for
different things, but it has worked for me.

[Jack H.]

Tough situation to be in.
It is equally hard to diagnose problems from far away with out having th einstrument in hand.

It could be a lot of different things. Thin bridge, weak bow, no rosin, porr fitting sp or bridge, I also have no idea whare your sound post lies or if the bridge is standig over the sp and the bb correctly.

Just want to wish you luck.
Maybe let it sit adn get back to it. Maybe cut a new sound post of the proper height adn fitment, new bridge, well fit feet, cut a bit thick....
Really hard to help out, but I have never run across a problem like that on the A string. although it might be a bad wolf, try a weight ( very light, Like some small split shot for fishing) on the string after the bridge towards the tailpiece.
Very light weight though.

good luck!

J

[Mat Roop]

Jethro... Try the rezx violin version...
http://violins.ca/accessories/wolftone_eliminators.html
I have found it helpful in diagnosing problems and trying to understand what is going on.
Cheers, Mat

[Jack H.]

Hence the reason I wanted you to put a weight on the string to see if that helped, if it did then you need a wolf eliminator.
Could it be that part of the belly is a bit thin???

[jethro]

Thanks for all of the ideas..... I will try a split shot on afterlength.
I reset the soundpost and noticed it wasnt perfectly verticle. I made it
exactly upright and pulled it to the outside a littl tighter than it was as it
seemed pretty loose where it was. I then started slowly working the bridge backward closer to the bridge about 1 mm at a time. That helped
it a bit but when I try to play a very piano note on A string I still get the
attack part of the note beiing an octive high.
I think it is my bridge cut. The string , given its own wishes, should want
naturaly to vibrate at its fund. freq. Some how my bridge must be
blocking 440 hz or enhancing the octive. It seems like I need to lower
the bridge frequency some. Would yall think this would be done by
removing a very small ammount of wood from the "arms" area on the
treble side ??? ( I am calling the arm the wood wetween the heart and the
kidney) I am immagining the bridge to be a spring/mass system and the
wood above the arms is the mass and the arms are the spring. Weaken the spring - frequency goes down......
The G string sounds fine. I get a lot on A and a little on E and D. This
makes me think the problem is on the treble side of the bridge.

I'm trying to be logical here ..... but I don't know if bridges follow
the flavor of logic I am trying !!!!!!!!

I will try the split shot. Then I will try thinning the treble arm a tiny
bit and listen for changes..... in the right direction.

Will ley yall know in case the logic works.

Tim

[Michael Darnton]

I'm not convinced this is a bridge problem, but if you want to lower the frequency of the bridge, the way to do that is by narrowing the waist.

[Jack Rushing]

Michael, Re- Narrowing the waist to lower the frequency. What would you

recommend the distance limit be, before getting it too narrow, and ruining

the bridge.

Thanks

[Michael Darnton]

Bridges often come somewhere in the 16-16.5mm range at the waist. 15.5mm is about the minimum for normal times, and I certainly wouldn't go below 14.5 under any circumstances (and have never approached that, myself). I usually trim only enough to clean up the curves, maybe a couple of tenths from whatever I've been given. You run the risk of the sound getting too rubbery/floppy, especially on the G string.

[jethro]

I tried a damping weight on the afterlength. No change.
Shaved a few thousanths off the arm (treble side) with scraper. No
change that I could hear. So then I started cutting the outboard
edges of the ankles thinner. It seemed to help. I took some more off
after that. That mostly fixed the problem. I can still hear it a little if I use a lightweight bow- but just a little. I think the rest would be just experimenting with the perfect post location.

PS.
Is there a tap test method that can be used to find the perfect sound
post location ?????????????

Tim

[jethro]

I get the feeling that Michael is maybe correct that the harmonic problem
isn't oregionating from the bridge but somewhere else like post location
or bar geometry or maybe graduation????????? -- even though my
bridge adjustment seemed to help. It doesn't seem too reasonable that my ankles should have to be really thin.

I love hidden variables !

Tim

[Jack H.]