SB Acoustics SB12NRXF25-4 Bass-midwoofer

The SB12NRXF25-4 Norex Bass-midwoofer from SB Acoustics is a meticulously engineered 4-ohm driver designed to deliver deep, controlled bass and articulate midrange performance in compact loudspeaker systems. Its construction reflects a commitment to high-fidelity audio reproduction, making it an excellent choice for discerning enthusiasts and custom installers alike.

This versatile woofer excels in a variety of applications, from sealed and ported bookshelf speakers to small subwoofer systems and multi-way designs where precise low-frequency extension is required. Its balanced parameters allow it to perform equally well in both closed and vented enclosures, offering flexibility for different acoustic preferences and room sizes.

Technically, the driver features a low total Q factor (Qts) of 0.48, ensuring accurate and well-damped response with minimal overhang. The mechanical Q (Qms) of 5.3 and electromagnetic Q (Qes) of 0.53 contribute to a clean, controlled transient behaviour. With a maximum linear excursion (Xmax) of 5 mm and a sensitivity of 87 dB (SPL 1m/2.83V), it offers a good balance between output and low distortion. The 4-ohm impedance and low DC resistance (Re) of 3.1 ohms make it amplifier-friendly, while the 0.27 mH voice coil inductance (Le) aids in maintaining high-frequency extension. The driver’s 101.6 mm nominal diameter and 69.8 mm depth allow for installation in compact cabinets, with four mounting holes for secure fitting.

In summary, the SB12NRXF25-4 is a refined bass-midwoofer that combines technical precision with practical versatility, ideal for those seeking authentic, room-filling sound from a compact driver.