The Concepts Behind Barbera Multi Transducer Bridges

MUSIC IS ENERGY, and the pickup is the first critical link in the projection of that energy. Like a lens, the pickup must collect and focus vibrational energy, then transform ("transduce") it into electrical impulses and project it onward. Tone, texture and dynamics require a refined sensitivity to be reproduced well. If the pickup is inefficient, musical energy is lost, poorly focused and distorted and musical performance is compromised.

The nuances of sound unique to violin family instruments require particularly sensitive treatment for amplification. The typical approach to violin family pickup design has been to attach a surface contact piezo transducer element in some fashion onto or under a traditional bridge. These approaches result in a surface sensitization effect (resonant surfaces of the instrument becoming microphonically active). This tends to yield a raw, unfocused or distant sounding signal which contains much microphonic "noise". Microphonic noise muddies up the amplified signal and creates a lack of clarity which does not project well in a mix with other instruments. This occurs because there is very little selectivity in the way the vibrational information is collected with surface sensitizing type pickups, everything gets amplified, including unwanted noise. Also, the traditional viol bridge is a structure designed to transmit string vibrations to a relatively large, acoustically resonant surface, not to a transducer element. For violin, a traditional violin bridge has very little mass, and a high resonant frequency which accentuates trebly, high frequency overtones. Keep in mind that when we hear an acoustic instrument through the air, the air is actually filtering out quite a lot of frequencies and noise present acoustically in the resonating surfaces of the instrument. Anyone who has ever placed their ear directly up against the surface of an acoustic instrument knows how "raw" and "boomy" it sounds. These properties become accentuated when amplified via a surface sensitizing type pickup. So while a traditional bridge does a great job of transmitting string vibrations to a resonant instrument top, it is not an optimized structure for transmitting vibrations to a transducer effectively.
Strings vibrate on a musical instrument in direct response to the resonant properties of the particular instrument on which they are strung. The strings and instrument are coupled together in an interactive loop. As a result, all the unique tonal information of the instruments voice is mirrored in the way that the strings are vibrating in response to the instruments resonant properties. This is true on both acoustic and non acoustic electric stringed instruments. With that in mind, BTS multi transducer bridges were designed to collect string energies directly by way of an integral multi transducer graft in the bridge. By collecting string energy directly, an exceptionally clear image of the instruments voice is produced for amplification, without the presence of microphonic surface noise, and with a high resistance to feedback on acoustic instruments. This is because the surfaces of the instrument are not microphonically sensitized. In addition, general handling noise such as knocks and thumps to the instrument body are not amplified.

Barbera pickup designs are unique. They employ a precision fabricated multi-element pickup cartridge made of maple which is grafted into a maple bridge. For Cello and Bass, traditional bridge blanks are thick enough to accommodate a multi transducer graft. Traditional violin bridges however are to thin to accommodate a graft, so special, thicker violin bridges were developed (the Hybrid and Standard/solid style bridges). The design compatibly integrates highly refined piezo transducer design concepts into a violin family bridge. The pickup cartridge contains an array of transducer elements, one (or two) transducers for each string depending on the model. Each transducer element within the cartridge structure functions as an independent pickup which is selectively sensitive only to its corresponding strings vibrations. The interactions of vibrating strings and wood are employed to maximum advantage in the multi transducer cartridge, which collects horizontal string vibrations directly (horizontal and vertical vibrations for Bass). For arco, the horizontal string vibrations are where all the rich complexity of sound occurs on a bowed string.

Twenty years after their introduction, Barbera Multi Transducer Bridges continue to evolve through ongoing refinements in both the design concepts and in the craft of how they are made. Barbera bridges are a highly responsive, feedback resistant pickup system for violin, viola, Cello and Upright Bass which is sensitive to the instruments full range of texture, tonality and dynamics. Barbera pickups yield a rich sounding full range audio signal, which accurately reflects the tonal personality of an instrument with striking presence, clarity, and depth.
The Bottom line is that the experience of playing music is greatly enhanced when the player has a high level of control over their sound. That high degree of control is what Barbera Multi Transducers Bridges are designed to provide.


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