At the recent ISE 2022 show in Barcelona, Beyma introduced the new NMF Series of woofers and tweeters designed to provide a high degree of linearity and negligible distortion in small- and medium-range applications.
The NMF Series is the result of a two-year R&D effort by the company’s engineering team employing multi-physic simulation as well as advanced prototyping techniques and measurement tools resulting in three woofers — 6NMFW (6-inch), 8NMFW (8-inch) and 10NMFS (10-inch) — joined by two tweeters — T25S (silk dome) and T25M (reinforced metal dome).
The woofers are outfitted with carbon fiber cones with high rigidity for pistonic behavior, proprietary Beyma QUATTRO voice coils designed to provide a high force factor to better control the moving mass, cast aluminium frames, electro coated metal parts to protect against humidity and age, Bimax spiders and high-resistance NBR surrounds for high linear and stable behavior.
The use of the latest simulation software for optimizing the motor structure helped in fostering highly linear behavior in the long excursion of the woofers. A magnetic circuit helps the QUATTRO voice coil attaining a more controlled excursion within the linear range, extending the dynamic range. The suspension system has also been carefully designed and optimize with geometry and materials tailored for high damping and excursion control, and avoiding common non-linearities and unwanted resonances on similar basic soft-suspension types.
Also onboard is Maltcross, a patented technology developed in-house that is at the core of high-level low-frequency drivers developed by Beyma. This “smart” feature is designed to provide a demodulating ring effect that balances inductance versus excursion as well as creating a 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.
The die-cast aluminum LEX design frames are optimized with advanced Finite Element Method software that offers a differential visual imprint in the drivers as well as optimized mechanical properties. A specially designed circuit is designed to interchange the air between the air gap area and the outside.
Meanwhile. the new NFM tweeters have been designed 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 tweeters ceramic magnets have been optimized with the latest FEA software. T-shaped pole pieces covered with a copper cap to enhance symmetric force factor figures. The copper reduces harmonic distortion figures to the minimum and keeps inductance down. Vented pole pieces flared on the top helps to get the steel saturated while avoiding resonances with damping material. Back radiation gets absorbed with three different carefully-selected damping materials behind the dome.
The T25M has an aluminum-magnesium alloy reinforced dome for enhanced linearity. The membrane moves as a piston above the audible range, pushing the break-up close to 38 kHz, reducing listening fatigue and helping to ensure clearer sound.
Further, its wide surround allows larger excursion and it is made out of a specific formulation polymer film. The shape has been optimized with finite element analysis software to ensure compliance symmetry exceeding the regular working range of a regular tweeter while providing exemplary on and off-axis figures.
The T25S offers a lightweight pre-coated silk membrane, resulting in a high-sensitivity tweeter with a high level of linearity. The copper-clad aluminum wire voice coil’s moving mass design produces output approaching a stated 92 dB along the working frequency range.
