... A proper tailpiece-to-fingerboard match is critical for best performance of your violin, viola, cello or double bass.
... Both volume and tone benefit when the tailpiece acoustically matches the fingerboard. The reason these two must work together involves the vibrating string. One end of the string is attached to the tailpiece and the other is anchored to the fingerboard by the stopping finger (or to the nut next to the peg box, if an open string is being played). When the string vibration reaches the end of the string, it reacts with the supporting structure (and the frequency of the violin at these locations) and is then reflected down the string again. If the frequency is different at the two ends of the string, it unsettles the vibration pattern which hurts the overall power and tone.
...If we are selecting a new tailpiece for our instrument, we want to pick out the one which most closely matches the fingerboard tap tone along its top surface.
...Tap down on the string bar of the tail piece where the string first touches. An ordinary wooden pencil (unsharpened of course) is good for this. {Try and select a pencil that has a rather dull tone when tapped against a hard object, so you do not hear the pencil more than your instrument!}
...Try and discover the predominant tap-tone (frequency) of the top surface of the fingerboard and match the tailpiece to this, or select the tailpiece that most closely matches the tap tone of the fingerboard top surface.
...All excellent instruments have this special acoustical characteristic:
The tail piece exactly matches the needs of the instrument.
... I believe that if you tap along the fingerboard top surface under a specific string from nut all the way to the end of the fingerboard on an excellent instrument, you will discover how even the 'tap' tone is. The result of this is that the notes will all be 'even'.
... Now if you tap down on the string bar on the tailpiece (the wood cross bar that first touches the string coming from the bridge) for that same string, you will discover that that 'tap' tone exactly matches that of the fingerboard's 'tap' tone. This is the factor that makes for maximum 'power' and 'focus'.
... It is this acoustical principle that will guide us to the ideal adjustment for each instrument.
...There is a great variety in tap tones (frequency) of new, apparently identical tailpieces. And since the taipiece can only be adjusted to +/- 10% of its natural frequency (tap tone) we must start with one that is a close match to our fingerboard inorder to be able to adjust it to acoustically match the fingerboard.
... I do not claim that the delicate reshaping necessary is either easy to do or to learn, but it is important to realize that it can be done.
The tailpiece frequency will increase slightly once the strings and fine tuner are added. {perhaps 10 HZ}.
To achieve the best effect, the acoustical match must be almost perfect between fingerboard and tailpiece, but 'close' will also be an important improvement.