X series membrane – Bass/midrange

This membrane is designed to achieve maximum stiffness with minimum noise. The technological requirements for this unrivaled high-end membrane performance made it necessary to design, develop and assemble all components in-house.

The X-series membrane that consists of three skins laminated into a single unit: two layers of spread carbon fiber, with a layer of aramid honeycomb spacers in between.

The combination of these materials gives this membrane its unique properties. The spread-tow carbon fiber was designed to provide a skin with optimal stiffness. This unique feature of the membrane reduces sound-disturbing vibrations and resonances to unprecedented levels. The aramid honeycomb also has the best stiffness-to-weight ratio in the vertical direction. A flat response membrane in terms of resonances paved the way to build a very transparent loudspeaker with a reduced size of the magnetic motor system to optimize costs.

X series magnet system – Bass/midrange

In the X-series magnet motor system, we use double copper caps on the pole rings to achieve high flux and low inductance. The use of copper caps has been adopted from the Børresen Z-series. Copper produces a response to flux changes – the better the counter-effect of these copper rings, the flatter the inductance curve, and the lower the electro-magnetic resonance. In addition, lower inductance also means fewer spikes in the impedance curve. Both result in a lower load on the amplifier. To ensure high efficiency, the X-series has two pole rings. This causes the loss of some flux, which reduces efficiency, but this is compensated for by a larger magnet.

X series Børresen tweeter

The tweeter chosen for the Børresen X-series has the same design used in all other Børresen loudspeaker series. However, there is a reduction in magnet and iron mass. This is possible due to the extremely high efficiency of the original tweeter design. As a result, the efficiency has dropped only slightly from the exceptional 94 dB to 90 dB, but this is still an amazing efficiency for a tweeter.

The tweeter operates from about 2.5 kHz upwards. The moving mass is extremely low at 0.01 grams. The fully concealed tweeter can operate at an impressive speed. The high robustness of this tweeter allows it to handle very high transients without causing any deafening dips.

X series cross over

The Børresen X-series is equipped with a parallel crossover built with the same high-quality components from the Z Series. This makes for a very mechanically stable crossover that minimizes its self-resonance.

X series cabinet

The surface of the cabinet is finished in black or white piano lacquer and reinforced with carbon fiber inserts. The cabinet is made of a heavily braced wood composite material that has the property of eliminating sound distortion. The material used for the cabinet also reduces mechanical influences, especially hysteresis. The sonic result is clearly audible. The X-series is equipped with bass reflex ports. The tweeter is vented to compensate for the air pressure that builds up. The bass section consists of tuned ports calibrated for musically relevant frequencies.