35FR

35FR was developed as full-range ferrite magnet driver. It has an excellent HF extension and provides good level of LF performance.
The driver was designed for usage in sealed speaker systems. It could be in column speakers, 2-way or 1-way speakers. It is also possible design a speaker system with a passive radiator to further extend the low frequency range.
Voice coil is wound with CCAW hi temperature wire directly on the Kapton former, ensuring good power handling and high temperature stability.
This driver brings good balance between performance and cost.
Depending on intended usage, we can deliver the driver either as 4, 8 or 16 ohm version.

The 35FRX8-406B is a 3.5-inch full-range driver featuring a ferrite magnet motor,
steel basket, FEM-optimized carbon fiber reinforced paper cone with NBR rubber surround,
Nomex spider, and a 25.4mm CCAW voice coil wound on a Kapton former. CCAW (copper clad
aluminum wire) reduces voice coil mass relative to a pure copper winding, yielding an
exceptionally low Mms of 3.1 g and high sensitivity at the cost of a slightly reduced
power rating (20W AES / 40W continuous). The FEM-optimized cone and surround geometry
and BL-symmetric motor circuit target low even-order harmonic distortion across the
excursion range. The driver is the 8 ohm variant of the 35FR family (available in 4, 8,
and 16 ohm versions), sharing the 93 mm overall diameter and 49 mm depth with the 4 ohm
companion 35FRX4-155 while offering a substantially different motor and suspension
characteristic suited to sealed and open-back column speaker applications.

Enclosure alignments:
- Sealed (primary - per manufacturer intent):
1.39 L / Qtc = 0.85 / fc = 173 Hz / f-3dB = 148 Hz
0.75 L / Qtc = 1.00 / fc = 203 Hz / f-3dB = 160 Hz
0.43 L / Qtc = 1.20 / fc = 244 Hz / f-3dB = 179 Hz
0.24 L / Qtc = 1.50 / fc = 305 Hz / f-3dB = 213 Hz
(Butterworth at 4.38 L / Qtc = 0.707 is provided as a reference but is impractically
large; Qtc = 0.85-1.20 is the practical column and bookshelf range)
- Free-air / open-back (secondary - column arrays with dedicated woofer):
f-3dB approx. 146 Hz; no enclosure required; high-pass filter at 100-150 Hz recommended

In column array applications, the 93mm driver OD limits coherent vertical directivity
to approximately 1.85 kHz - the lowest in the full-range family (shared with the 4 ohm
35FRX4-155). Multiple 35FRX8-406B units can be wired in 2x parallel (4 ohm) or 4x
series-parallel (8 ohm) configurations for standard column array loads. The 16 ohm variant
enables 4x parallel wiring to a 4 ohm amplifier channel. A high-pass filter at 80-100 Hz
is recommended in all installations to protect against over-excursion below Fs (128 Hz).

The 35FRX8-406B is suited for high-sensitivity sealed column speaker systems requiring
87.5+ dB 1W/1m output from a compact 3.5-inch driver with 8 ohm system impedance; 2-way
bookshelf and surface-mount loudspeakers where the sealed Qtc = 0.85-1.20 range
(0.43-1.39 L) provides an efficient, compact enclosure for midrange and upper bass;
open-back column panel designs crossed above 150-200 Hz to a woofer, where free-air
mounting simplifies construction; and installed sound and PA column systems requiring
FEM-optimized low-distortion full-range coverage up to approximately 3,000-4,000 Hz
with a dedicated tweeter above that point.