hamberger soundpost

Patented Activ-Dynamic Principles (ADP)


The Invention

For the first time, it is now possible to vary acoustically decisive factors such as tension and position of the sound post independently from one another while constantly preserving a perfect fit thanks to the flexible ends. The carefully selected composition of materials (NO carbon!) of HAMBERGER SOUNDPOST allows for a natural oscillation behaviour within the instrument and creates a sophisticated timbre.

The patented Active-Dynamic Principle (ADP) of HAMBERGER SOUNDPOST makes the installation particularly easy. HAMBERGER SOUNDPOST can be positioned in the instrument in an unscrewed state by exterior magnets and fixed with an adjusting rod once the perfect position is found. The tension of the HSP can be increased or decreased at any time without altering the position. The change of sound thus created is immediately perceptible to the player. Installing the HSP is very easy, but we still recommend it being fitted by an expert.

"The manufacturer will not be liable for damages on your instrument owing to inappropriate handling of Hamberger Soundpost"

The sound post comes in a set including the sound post with setting dial, magnetic adjusting rod, 2 positioning magnets and 2 position indicators. An adjusting screw with detachable setting dial with adjusting key is available as an option.

The sound of testing instruments was shown to change significantly by changing the position of the HSP. This allows you to improve the sound of your instrument with minimal effort.

An interesting factor here is the very low variation in length: adjusting the dial by “one hour” compared to the original state only accounts for 0.7/12 = ca. 0.0583 mm upwards resp. downwards, i.e. about 6/10 mm.

Advantages of the Hamberger sound post compared to the spruce sound post:

  1. The possibility to finely adjust the length and thus change the sound. With the traditional spruce sound post, creating a variation similar to what the length variation of the Hamberger sound post offers would require several sound posts with slightly varying length to be produced for the same position and tried one after the other. The production of e.g. three sound posts with differences in length of ca 6/100 mm can already be considered quite “ambitions”. Here, the slanting front faces of the sound post increase the inaccuracy of the measurement of length. Additionally, the angles of the slants would have to be absolutely identical to avoid the interfering influence of a bad fitting.
  2. The possibility to slightly shift the sound post and to optimise the length in this new position. This way, the two parameters “length” and “position” can be varied independently from each other. When shifting the traditional sound post, the parameters “clamping force” and “position” are changed, thus mixing their influences on the sound.
  3. The little feet mounted in the ball joints that ensure a continuously good fitting to the base/top. Since the base and top layers in the sound post area form highly complex angles and can hardly be depicted exactly, the fitting in one or both of the two contact points is likely to be less than perfect in a large number of traditional sound blocks.

Every expert and every interested string player understands the significance of the sound post and its different parameters for the sound of the instrument. It has been recently shown that a spruce sound post of the perfect length that provides the best possible sound of the instrument is only partly down to the great skill of the violin maker. The rest is pure luck, because (as described above) a test run with sound posts of varying length can be practically excluded. From this it can be concluded that a considerable amount even of top-scale instruments is probably equipped with less than perfect sound posts…

This new development provides an unprecedented insight into the significant influence of even minor changes in length on the sound. With the traditional spruce sound posts, it was impossible to know anything about this new scope of influence. So the HSP is an innovation that is both ground-breaking and easy. It allows an increase of the sound of any given instrument beyond the limits known before.

The advantages

  • Optimal space for the sound quality and tone richness of the instrument
  • Simple and precise articulation
  • Complete equilibrium
  • Sophisticated and undistorted timbre
  • Extraordinary projection
  • Perfect accuracy of fit
  • Very simple installation within a few minutes
  • An indefinite number of setting variations with one single sound post within a short period of time




„In most cases the minimum tension as much as 1/12 turn of the setting dial brings the perfect adjustment result.” Wolfgang Hamberger, Inventor



Thumbnail Image 1



Thumbnail Image 1



Thumbnail Image 1



Thumbnail Image 1

Double Bass