The pressure you apply on the bow affects the tonal quality of your violin. Since the first finger on your bowing hand applies the majority of pressure, to improve violin tone practice improving your control of the pressure you use on each bow stroke by alternately increasing and reducing the pressure you apply with this finger.
Bow Location (Straight Bow)
Where the bow makes contact with the strings makes a difference too. This is why ‘straight bowing’ is emphasized so strongly during the first years of study. There is a sweet spot located on the strings relative to your specific instrument and when your bowing is utilizing only that area, the sound produced has more depth and clarity. To improve your technique, try adding three minutes of straight bow practice warm-ups each time you play.
The amount of rosin you use on your bow also affects the tone and sound of your violin. Too much rosin on the bow hair produces a scratchy, unpleasant sound, while too little will cause the tone to fade out during your bow stroke. Finding exactly the right level of rosin to apply is like everything else involved with learning to play the violin… it takes practice. If you have too much rosin though, rather than trying to clean the bow hair, which can reduce the capability of the bow to create a crisp, clear sound, simply play until it wears off. (But, don’t forget to wipe off your instrument and strings afterward to prevent rosin build-up.)
This is another factor that has a subtle, yet distinct impact on the tonal quality of your play. While your teacher or instructor can help you best, a few things to keep in mind to improve violin tone through bow grip include:
Replace your Strings
Sometimes the problems you’re having with tone are less related to the way you are playing—more related to what you are playing on. Replacing or upgrading your strings can have a significant impact on the sounds you are able to produce on your violin. Nylon or synthetic core strings typically generate warmer, more pleasing tones and are a great choice for beginner or intermediate level violinists. These style strings are also a bit easier to play.
You can improve violin tone and the overall tone and sound quality of your violin by sticking to the mechanics. Many students find that their tonal quality drops off as they advance, but this is often due to a slackening of proper playing form. As your intonation improves, you’ll notice subtle differences that you couldn’t hear before.
By rigidly adhering to the basic rules of bowing and possibly replacing your strings, you’ll be able to soon develop richer, more beautiful melodies with fuller sound; taking your listeners on a journey out of themselves and into a realm of emotional joy through the music you create.
Source and Citation: http://www.connollymusic.com/stringovation/6-ways-to-improve-violin-tone
The Violin and the Viola are both members of the string instrument family, they look quite similar and are both held under the chin and played with bows.
While the two instruments look alike and in fact are close cousins, there are quite a few differences that make them stand out from each other with equally strong and unique voices.