The D. A. C. violin bridge

Messung der Admittanz am Geigen-Steg vom Typ DAC auf der Seite der Diskantsaiten

2008/9 proceeded with a new idea. The master luthier experimented with a new violin bridge which changed the conventional perception of a violin bridge. The normal bridge is considered “narrow” and “undefined”.
He designed the new D.A.C. Bridge with a larger contact surface, and he searched for increased flex and quicker transmission of the string impulses. Conventional bridges lose a lot of energy by seesawing.

Now, the D.A.C. Chouard sounds vastly more open, clearer and richer. Renowned musicians from the Munich and Salzburg areas have become acquainted with the bridge: they are in awe.

The experience of Hervè R. Chouard in guitar building has great impact and benefit on his master violins. According to violinists, the innovation of the bridge has been a huge development step in modern violin making. This has been confirmed by measurements at the faculty of Psycho-acoustics at the Bundeswehr University in Munich / Neubiberg (more technical report und Conclusions)

The D. A. C. violin bridge - gallery

Geigensteg D.A.C bridge von Herve Chouard

Geigensteg D.A.C bridge - Version 1

Geigensteg D.A.C bridge von Herve Chouard

Geigensteg D.A.C bridge - Version 1

Geigensteg D.A.C bridge von Herve Chouard

Geigensteg D.A.C bridge - Version 2

Geigensteg D.A.C bridge von Herve Chouard

Geigensteg D.A.C bridge - Version 2

Conclusions (Part of the technical report)

Undoubtedly, generally the admittance at the contact points of the strings and especially its real part, the conductance, is the adequate parameter. It is well-suited to ascertain by a measurement technique differences in the musical function of bridges mounted on an instrument. To account for the mode of operation of hearing, which is the very receiver of violin tones, for the visualization and interpretation a logarithmic scale is better suited than a linear one. Since this presentation mode was not available for the real part, alternatively the magnitude of admittance was measured and discussed. A tentative study has shown that the prominent cues of a conductance frequency curve can be also found in the admittance curve.

Frequency responses of admittance were measured at two bridges, a traditional one and a bridge of the novel DAC type. They were compared and discussed, revealing similarities and differences. Similarities showed up for frequencies up to about 2000 Hz (note h3). For higher frequencies, the admittance measurements mentioned above (Figures 7 and 8) have shown pronounced differences. Beyond about 2000 Hz the admittance of the DAC type bridge is at least three times as large as the admittance of a traditional bridge.

Hence, the DAC bridge has the ability to accept more vibration energy than the traditional bridge. This is the fundamental precondition for the transfer of more energy from the string to the instrument body. The high bridge admittance measured is not a sufficient but a necessary requirement for a violin to radiate tones above about the note h3 with a higher level than this is possible using the traditional bridge. According to the measurement results, the gain in acoustic pressure can amount up to a factor of three. On a level scale, an increase by up to ten decibel is estimated. For treble violin tones, this corresponds to doubling the loudness. For lower violin tones, the consequence is a considerable accentuation of higher-frequency spectral components. This will modify the timbre towards a higher brilliance.