Hi, I have a cheap cello and an er hu, and since buying them, I realise that when I play a specific note, F# for my cello, and A for my er hu, the whole instrument will start to vibrate, producing an uncontrollable vibrato like sound. Does anyone know how to fix this?

that happens when the note matches the instruments natural vibration frequency or whatever its called.
from what i know theres no real way to fix it, but u can add mass to change the note that it vibrates at.
or maybe u can try adding some form of dampener in it.

Everdying is right... All musical instruments have that "resonating note", my Trombone has it too but it's not really annoying...

But I believe higher end instruments don't have this problem, I wonder why...

it's called resonance in science!!!

put more dampener under your erhu bridge. Make sure the dampener touches the bridge bottom part. Used toh ave that prob with Erhu...now ok d.

Now my Zhonghu has slight resonance with the high 'g' note on the G string.

every instrument will have a note or 2 resonate more, regardless obvious or not.

but if it's sort of like a out of control vibration, it's commonly known as a "wolf note" on musical instruments.

http://en.wikipedia.org/wiki/Wolf_tone

it also mentioned that the F# is pretty common for cello, which matched your situation. fortunately, there's the eliminator mentioned in the wiki link above, you can get it in string instruments shop like euro music, carismen dolce, chamber music, early music venture, etc etc.

even stradivari that cost millions of dollars will have this, watch the video.


This post has been edited by little ice: May 17 2009, 12:31 AM

Of course it's called resonance, and that's not only a science term, it's a term for general use.


Thanks a lot for that info, didn't know that it's called wolf tone
I've tried many violins, from RM 400 - RM 10K, spent quite some time with them, but somehow I never find this problem on them. Perhaps I didn't pay close enough attention to it, or maybe it's just not so obvious.

This post has been edited by kheechun: May 17 2009, 08:25 AM

it's a hit and miss thing, like a lucky draw. also string instruments, due to setting up and adjustments (and wood develop/seasoning), will develop wolf after some time. if you bought one that's wolf-free, and has remained like that for long time, then congratulation.

on my violin (which cost more than the price range you mentioned), is quite balance through out the register. i find it has something to do with the bow too, one of the bow will produce even and wonderful strong sound, while using the other bow will always bring out the C/C# (which is common for violin) that's annoying, though not overly so, i'd call it a slight wolf, it sounded too boomy and muddy for the C/C#, especially on the lowest on the G string.

PS: just found out the video doesn't allow external link, simply click on the video player to bring you to the original link.

This post has been edited by little ice: May 17 2009, 01:54 PM

To make it easy:
http://www.youtube.com/watch?v=a7pQGuSL7uo

go n ask your teacher..

resonant frequency..like you said,its the natural vibration of the instrument matching the vibration of the string..
even when you place your guitar on a stand and play some music on your speakers, some strings will start to vibrate;the strings are matching the frequency of the music played on the stereo.

even in mythbusters,they tried to create a troop of marching soldiers to march on a bridge and cause it to oscillate (resonnace, in a way) with the bridge and cause failure of the structure..

This post has been edited by ryan_hustler: Jun 15 2009, 02:47 PM