40NFR/41NFR

41NFR was introduced as part of our new range of smaller transducers. The model is focusing on improvements in frequency response, both in LF and Mid-Freq. Powerful neodymium ring based magnetic structure delivers the highest levels of moving force onto the voice coil with minimum distortion artifacts.
The cone and rubber surround were further FEM modeled and deliver incredible performance.
41NFR was designed for column speakers, micro line-array systems and two-way audio systems. Due to its good performance in high frequencies, this driver can be used without HF unit, which opens new opportunities for the system engineers to design compact, yet good sounding products.
Our newly developed basket with typical REDCATT shapes, utilizes tall front EVA gasket and 1mm rear gasket. The driver can be thus mounted from both sides of the baffle.

The 41NFRX16-464A is a 4-inch full-range driver featuring a neodymium ring magnetic
circuit optimized for minimum flux modulation, a steel basket with dual-gasket mounting
system (tall front EVA gasket and 1 mm rear gasket enabling front or rear baffle
installation), FEM-optimized carbon fiber reinforced paper cone, NBR rubber surround,
Nomex spider, and a 25.4mm copper voice coil wound on a Kapton former. The copper
winding provides higher conductivity and improved thermal handling relative to CCAW,
supporting the 40W AES / 80W continuous power rating - the highest in the full-range
family. The neodymium ring motor develops Bl = 10 T.m, more than twice the force factor
of the ferrite drivers in the lineup and nearly double the other neodymium variants;
this is the primary contributor to Qts = 0.37, Xmax = 3.15 mm (one-way), and the 17.88 cm3
volume displacement - all peak values in the family. The driver is designed for column
speakers, micro line-array systems, and 2-way audio systems, with front/rear mounting
flexibility suited to varied column cabinet geometries.

Enclosure alignments:
- Vented (primary) - 40 mm port:
4 L / Fb = 80 Hz / ~118 mm physical port / 7.15 m/s peak port velocity
5 L / Fb = 75 Hz / ~105 mm physical port / 6.70 m/s peak port velocity
7 L / Fb = 65 Hz / ~98 mm physical port / 5.81 m/s peak port velocity
(Port physical lengths span 98-118 mm across all three tunings - near-constant
20 mm range; all velocities well below 17 m/s hi-fi limit)
- Sealed (secondary - sub-assisted or 2-way):
0.79 L / Qtc = 0.707 / fc = 187 Hz / f-3dB = 187 Hz
0.33 L / Qtc = 1.00 / fc = 265 Hz / f-3dB = 208 Hz
0.22 L / Qtc = 1.20 / fc = 318 Hz / f-3dB = 234 Hz

In column array applications, the 104.5 mm OD limits coherent vertical directivity to
approximately 1.65 kHz; a co-located tweeter is mandatory. Four drivers in parallel
produce a 4 ohm load on a standard amplifier channel. A subsonic high-pass filter at
Fb - 10 Hz (55-70 Hz, depending on alignment) is mandatory to prevent mechanical
over-excursion below the vented port tuning frequency, where cone displacement rises
rapidly and Xmax = 3.15 mm can be approached under sustained low-frequency drive.

The 41NFRX16-464A is suited for high-output column speaker and micro line-array systems
requiring maximum SPL (105 dB) and genuine bass extension (65-80 Hz Fb) from a 4-inch
vented enclosure with 16 ohm parallel array wiring; 2-way active or passive loudspeaker
designs where the neodymium ring motor, high Xmax, and 40W AES power handling are the
primary selection criteria; front-loading and rear-loading column cabinet configurations
where the dual-gasket mounting system simplifies assembly; and professional installed
sound applications where the highest output-per-driver in the 4-inch full-range class
is the principal design objective.