123FPM

ENCLOSURE RECOMMENDATIONS: 123FPMX4-188B
Driver: 123FPMX4-188B (123FPM) — 12" Mid-Woofer
Key T/S: Fs=45.0Hz, Qts=0.27, Vas=98.5L, Sens=97.75dB
Power: AES 300W / Cont 600W / Peak 1200W
Xmax=2.75mm, Sd=531.0cm², Bl=12.8T·m
RECOMMENDED ENCLOSURE TYPE: Bass Reflex (Vented)
PORT RECOMMENDATION: Round port (100mm diameter) — standard for mid-size professional enclosures; good balance of area and packaging
  a) High SPL
     Net Volume: 70 liters
     Tuning (Fb): 52 Hz
     Est. -3dB: 48 Hz
     HP Filter: 44 Hz (24dB/oct recommended)
     Round Port: 100mm dia × 49mm long
     Slot Port: 226mm W × 60mm H × 114mm L
     Port Velocity: 6.0 m/s
     Notes: Strong mid-bass impact, reduced cone excursion, maximum output
  b) Balanced Response
     Net Volume: 80 liters
     Tuning (Fb): 47 Hz
     Est. -3dB: 43 Hz
     HP Filter: 37 Hz (24dB/oct recommended)
     Round Port: 100mm dia × 59mm long
     Slot Port: 226mm W × 60mm H × 131mm L
     Port Velocity: 5.5 m/s
     Notes: General-purpose PA/subwoofer, even response, good transient behavior
  c) Extended Low Frequency
     Net Volume: 90 liters
     Tuning (Fb): 43 Hz
     Est. -3dB: 37 Hz
     HP Filter: 31 Hz (24dB/oct recommended)
     Round Port: 100mm dia × 74mm long
     Slot Port: 226mm W × 60mm H × 157mm L
     Port Velocity: 5.0 m/s
     Notes: Deep bass extension, requires proper system protection below tuning
--- Summary ---
The 123FPMX4-188B is a 12-inch mid-woofer driver designed for professional 2-way and multi-way systems requiring high sensitivity (98 dB 1W/1m) and controlled low-frequency behavior. The motor and suspension are optimized to maintain consistent performance at high drive levels, with controlled excursion and reduced thermal compression during long-term operation.
In bass reflex enclosures, the driver performs best in net internal volumes of 70 to 90 liters, tuned between 43 and 52 Hz. This alignment provides a balanced combination of low-frequency extension, cone control around resonance, and efficient port loading. Lower tuning improves deep bass extension but increases excursion below tuning, requiring appropriate high-pass filtering. Higher tuning increases sensitivity and output in the upper bass region while improving mechanical control.
The driver is intended for use with high-power amplification (approx. 300 W AES / 600 W continuous) and DSP control. A high-pass filter in the range of 31–44 Hz is recommended depending on enclosure tuning, along with proper limiting to manage thermal and mechanical stress. Typical operating bandwidth is 37–2000 Hz, covering bass through upper-mid frequencies for direct integration with a compression driver or tweeter in a two-way or multi-way system.