VIOLIN MATTERS - THE SOUND POST

VIOLIN MATTERS                            

THE SOUND POST

“If the edges of the sound hole are uneven and there is no clear ringing tone of the adjacent strings- it should raise an alarm bell”

Introduction

'Sound post' is a cylindrical rod of usually wood which is placed inside the body of the violin . 

It is positioned inside the violin at a level adjacent to the bridge near the E string .

The Soul 

Sound post is placed between the front plate and the back plate of violin supporting the arch of the violin. 

It alters the tone of the violin and is often referred to as ‘the soul’ (ame) of the violin.

Ideal position of the sound post inside the belly of the violin is 1-3 mm behind the bridge position and 1-3 mms inner to the right foot of the bridge.

Fig 1. Position of the sound

(From Andrew Filmer with thanks)

Moving the sound post towards (1) the bridge gives a louder and harsher sound.

Moving the sound post away from the bridge (2) gives a mellow and lesser volume sound.

Moving the sound post to the left (3) or to the right (4) will increase focus on the adjacent strings.

Not only the position but also the make of sound post is important – the grains meaning the lines along the tree growth should  be at 90 degree angle to the grain of the instrument. 

The touching ends of the sound post should also be carved to the shape of the breast of the violin so that the contact is full and complete.

Sound post is generally erect, but can be slightly at an angle. 

Adjusting the sound post is just not physical, but the tone of the violin should be heard, felt and appreciated to a better one. 

Each violin is different in its temperament and only general principles of the sound can be laid.

Its position can be altered inside the violin via the sound holes with a setting tool by the luthier.

 Fig 2. Sound post setter tool

Problem

• My violin makes a clear ringing tone on the open strings of G and D. 
• But the clear ringing tone was absent on strings A and E.  
• To find out the exact nature, I took a picture of the sound holes of the violin from the front which looked apparently normal.

Fig. 3. Apparently Normal Looking Sound holes

I also palpated the body of the violin and found the edges of the right sound hole were at uneven depth. The inner edge of the right sound hole was raised compared to the left sound hole as though the sound post was keeping the front and the back plates of the violin apart.

                             

Pic. 4.  Left Sound Hole - Edges Even.

Pic. 5. Right Sound Hole- Edges Uneven and Apart

Solution

So I took this up with the luthier to readjust the sound post.

He confirmed my findings and readjusted the post to an inner position. 

The front and the back plates of the violin body were no longer under tension.

The edges of the right sound hole became more even.

The price of the pudding was that the sound returned to the A and E string – louder, clearer and what is more , the ringing tone of the open strings A and E had returned!

"There is more to it than meets the eye!"

By the way my age-old bridge had a minute crack on its back surface and we replaced this as well and the sound was far superior. 

So it is important to know that the sound depends on factors far more than just the sound post!!

So keep looking for causes to improve your tone - not only in your playing, but also in the violin!

Remember 

       “If the edges of the sound hole are uneven and there is no clear ringing tone of the adjacent    strings- it should raise an alarm bell”