In Beyma we face the problem of heat dissipation with a clear goal in mind: the speaker must deliver the best performance in the system in a consistent and reliable way, maximizing the total SPL and keeping it stable.
It is well known how the overall SPL of a system suffers a drop after some time working due to the power compression effect in the speakers. It is also known that normally the bigger the voice coil diameter the higher the power capacity, but this also means bigger motor structures to obtain high total output from the transducer.
The Maltcross cooling technology that we deliver to the Professional Audio market through our speakers, bring together several solutions to meet our goal; in one side allows the woofer to handle bigger rates of power with a given coil diameter, so we can think in smaller coil designs with smaller motor structure, reducing the weight but increasing the sensitivity and also keeping an adequate power handling figure for a target application, maintaining a total SPL finally that may be equivalent to a bigger size motor structure driver.
The Maltcross technology is a forced convection circuit inside the heart of the driver that helps to lower the working temperature of the coil and also acts like a demodulation ring, linearizing the inductance of the transducer.
Any channel through which a sound is transmitted has its eigenmodes. If we think in an analogy with the transmission of plane wave inside a tube closed by a diaphragm and open in the other end the modes can be easily calculated, although the problem is much more complex in the case of the compression driver ducts . Those modes will result in valleys and peaks that worsen the frequency response.
Our R&D team after much thought and extensive research, simulations and tests to improve the frequency response of our compression drivers has come up with this unique solution.
The working principle to solve this complex problem is quite simple. Through the variation of the duct shape, it is possible to linearize the response of the system and obtain a better transfer function.
Variations in the tube in width and a sort of organic shape designed according to different mathematical functions will create a notable variation of the sound pressure level for the calculated frequencies resulting in a much better transient response.
In a sector in which high performance is of great importance, when designing the coil configuration, the one layer edgewound wire or the double layer round wire coils are traditionally used to obtain the necessary Bl if the high SPL required in the industry is to be achieved.
This technique, in the case of the double layer configuration has the drawback that one of the coil layers is not capable of dissipating as much heat as the other. And normally the flat wire configuration features a short magnetic gap. Therefore, power handling is limited and power compression due to high temperatures makes its appearance with much less voltage.
Through DEPLOCEX, the surface of the coil and the magnetic gap is maximized, deploying the coil in a configuration to increase the heat dissipation through radiation, while maintaining the same Bl and final SPL. The thermal transmission of the entire length of the coil with the iron is higher.
The coil temperature is reduced by 30% which minimizes the effect of power compression and achieves high frequency drivers more than 15% more powerful.
Our R&D department implements in close cooperation with the Technical Office practical experiments to illustrate, show, and transmit the acquired knowledge.
As an example, a good result in the research of new materials has been the new PM4 diaphragm, which incorporates a new high tech polymer never used in audio before.
Delivers a stronger joint between the dome and the former of the voice coil and so a better behavior with high power handling and long periods of working.
In the subjective field, which is also a relevant part in the Beyma development process, in our opinion it brings a more natural sound when comparing it with other polyesters.
The increase of temperature in a pleated diaphragm strains every fold, limiting the electrical power it can handle. The target of Xbow Technology is to open as much as possible the constraint in the diaphragm, allowing it to manage higher temperature rates and so increasing the limit of the power it can handle.