audioXpress visited Beyma at ISE 2022 to see the new NMF (Near and Mid Field) series of drivers, which was the complete focus for company at the Barcelona show. For now, the series includes five drivers - three woofers and two tweeters. The whole Beyma team was extremely excited to show the results of their extensive R&D efforts for the first time in-person, particularly given that the whole series expands the company's market to new exciting application areas.
At the booth we had the opportunity to speak with transducer engineer Diego Ivars, who joined the company's R&D department in 2020, after almost a decade of experience with SEAS in Scandinavia, in both transducer design and manufacturing. As Diego Ivars explains, this series benefits from extreme linearity and negligible distortion that excels in small and medium range listening distances where attention to detail is paramount. "The NMF defines a new grade of glassy, unspoiled sound in which the best part of contenders are left behind," he states.
The Beyma engineering team is determined to challenge speaker designers from the high end audio market to consider these latest drivers. "Some of the best engineers in our organization have been enthralled in a two-year quest using state of the art multiphysic simulation, leading prototyping techniques and unsurpassed measurement tools resulting in these precise devices working in flawless harmony. Years of experience and know-how together with cutting-edge technologies have resulted in a new generation of drivers created to perform in outstanding studio monitor and high-end loudspeaker enclosures," the company states.
NMF Woofers
The new woofers in the NMF series, 6, 8 and 10-inches are immediately distinctive for its elegant design, and use of top quality materials, which contribute to the driver's sonic properties. Common to the three woofers we can find carbon fiber cones with high rigidity for pistonic behavior, unique Beyma QUATTRO voice coil for a high force factor to better control the moving mass, cast aluminum LEX-design frames, electro coated metal parts to protect against humidity and age, Bimax spiders and high resistance NBR surrounds for high linear and stable behavior. All these parts working together result in a consistent and robust performance even at very demanding conditions and long working cycles.
The use of the latest simulation software was key to deliver extremely linear behavior in the long excursion of the woofers, optimizing the motor structure. The magnetic circuit combined with Beyma's exclusive QUATTRO voice coil provides a more controlled excursion within the linear range, therefore extending the dynamic range. The suspension system has also been carefully designed and optimized, with geometry and materials tailored for high damping and excursion control, avoiding common non-linearities and unwanted resonances on similar basic soft suspension types.
As Beyma also details, its R&D team developed a careful geometric design of membrane, dust cap and density for appropriate damping, in order to obtain the most linear response possible, taking special care to the off axis response, for a controlled acoustic dispersion up to the crossover region.
And of course the NMF series also benefits from Beyma's Maltcross patented technology, that is at the core of the best professional low frequency drivers developed by the Valencia-based company. This feature provides a demodulating ring effect balancing the inductance versus excursion and allows a superlative cooling circuit where the air flows inside the airgap towards the voice coil in turbulent mode. Reduction in temperature and demodulation provide less power compression, higher SPL and less distortion at low frequencies.
All these features allow speaker designers to implement cabinets that can work from the very low end, up to the crossover frequency to the high frequency driver. The “friendly” crossover design makes it possible to obtain an extremely linear response, controlled excursion, damped unwanted resonance modes and extended and smooth breakup behavior.
As mentioned, the new Beyma NMF woofers stand-out aesthetically due to the use of exclusive die cast aluminum frames, FEM-optimized to offer a differential visual imprint in the drivers and optimized mechanical properties. As proven already in the original LEX series where these frames were first implemented, the result also delivers efficient heat dissipation, thanks to the special air circuit that interchanges the air between the air gap area and the outside.
NMF Tweeters
The new NMF tweeters have been developed to fulfill the needs of the professional industry, embracing challenging design goals from the outset, to align expectations with the most demanding applications. The knowledge that Beyma has been gathering over the last decades of manufacturing compression drivers has been used in these tweeters. Tight tolerances, close control of the parts, meticulous manufacturing processes, and precise assembly, result in very high consistency and superior performance.
As Beyma details, the design allows these tweeters to be mechanically coupled to the cabinet. A stiff aluminum die cast back chamber is directly braced to the cast aluminum front plate, holding together the entire assembly firmly as a whole. The magnet system has also been optimized with the latest FEA software to squeeze the ceramic magnet to the limit. A T-shaped pole piece covered with a copper cap delivers extremely symmetric force factor figures, and the copper minimizes harmonic distortion while keeping the inductance down. A vented pole piece, flared on the top, working with three different, carefully-selected damping materials to help absorb back radiation and avoid resonances behind the dome. Finally, for directivity control, an optimized waveguide improves off-axis response helping system designers to achieve a good spinorama chart.
For the new NMF series, Beyma offers two different approaches with reinforced metal dome and a silk dome. The T25M tweeter features a carefully designed aluminum-magnesium alloy reinforced dome for frequency response linearity. The piston motion of the membrane's material pushed the break-up close to 38kHz, above the audible range, reducing listening fatigue and ensuring crystal clear sound and brilliant performance in the traditional working range.
Its wide surround made out of a specific formulation polymer film allows larger excursion. The shape has been optimized with finite element analysis software to ensure compliance symmetry exceeding the regular working range of a regular tweeter while resulting in outstanding on and off-axis figures.
Alternatively, the NMF series also offers the T25S tweeter, featuring a lightweight pre-coated silk membrane resulting in a high sensitivity tweeter with excellent frequency response linearity. Together with the copper-clad aluminum wire voice coil, Beyma says this high-frequency driver delivers close to 92dB along the working frequency range.
The series is sampling now, and Beyma created a dedicated website for the new NMF series, which includes more information, measurements and datasheets.
www.beyma.com/nmf
