Tuesday, June 14, 2011

The Soundpost

Written by: Andy Fein, Luthier at Fein Violins

The soundpost is the dowel of wood that you see inside the treble (E or A) side of your violin, viola or cello. For a small piece of Spruce that's about 6mm thick (about 7mm on a viola, about 10mm on a cello) it makes a tremendous difference on how your instrument plays and sounds. In French, the soundpost is called "l'âme", the "soul" of the instrument. I completely agree.

Picture of soundpost inside a cello

Generally, the soundpost is placed a millimeter or two (somewhat more for viola and cello) inside the bridge foot, and the same distance behind the bridge, with a small amount of tension (snugness). BUT, that's just a general guideline and a good starting place. From there, you and your violin maker have to use your ears and your intuition. What sounds best? What plays best? What is best for the instrument? Trust your basic instincts as a player. What feels best?

Here are some general rules of thumb. Unfortunately, they don't apply to every instrument or everyone's ear. Use your ear and your intuition to assess what is best for you and your instrument.

1. As you move the soundpost towards the inside of the instrument you change the tonal balance more towards the bass side (D & G on violin, G & C on viola & cello) of the instrument.

2. As you move the soundpost further behind the bridge the response of the instrument becomes easier (less bow pressure) but also less focused.

3. A tighter soundpost will make the instrument more focused, respond faster and have better projection but will need more bow speed or pressure. However, too tight of a soundpost will lead to huge structural problems and cracks!

4. There is a triangular relationship between the instrument, the bow, and the player. Use the same bow each time your instrument is adjusted.

5. Every player needs a slightly different adjustment for the instrument to sound best. The instrument is not adjusted to itself. It should be adjusted to you and your bow. No one else plays with your bow arm. No one else hears with your ears. Make sure your instrument is adjusted for you. Don't have it adjusted for your best friend or stand mate. They're not playing it. You are.

6. If your soundpost falls when you change strings or just on its own, you need a new soundpost that is a bit snugger. For most instruments, the soundpost should be snug enough to stand on its own without any string pressure.

7. When you and your violin maker are making soundpost adjustments, make sure it is tuned exactly as you are going to be playing it. For most U.S. orchestras and halls, the reference is A 440HZ. Changing the tuning up or down will change the pressure on the top of the instrument and might necessitate a different adjustment. But, don't micro-adjust your instrument for one concert with a slightly high or low tuned piano. You will drive yourself, your instrument and your violin maker crazy!

8. The quality, age, and grain width of the Spruce will affect the sound of your instrument. The cost difference between very good soundpost material and lousy soundpost material is minimal. There is no reason not to use very good to excellent quality Spruce for your soundpost. It will make a world of difference.

The soundpost creates a node (a non-vibrating area) on the top and back of your instrument. As you change the position and snugness of the soundpost you are changing the vibrational properties of your instrument. It really is the soul of your instrument.

Here's a fun video of me setting a cello soundpost to a Bach cello suite.

Are you a string musician or interested in becoming one? Take a look at our Fine Violins, Violas, and Cellos!

1 comment:

  1. Hi, I am a amateur fiddle player.

    What I lack in giftedness and background...I make up for in devotion and enthusiasm!

    I have half a dozen instruments. From a 15in viola to a 22 in Viola d Gamba. & a pretty nice cello.
    None of lofty make.

    I live in the Appalachian mountains , am self tough and live simply on a unlivable budget.
    I play by ear and read and can play all my fiddle OK.

    I have taken my 'fiddles' to several local luthiers, and have experienced some disturbing results.
    So I now read all I can to ...somehow learn to help myself ..fix issues with my beloved fiddles.

    This was a wonderful and informative site!...I am still a bit unsure of setting my SEVERAL loose sound posts.. but...at least I feel SO much more knowledgeable!

    THANK YOU for your help!