The 4¾” transducers WF120BD05/WF120BD09 (4 ohm) and WF120BD06/WF120BD10 (8 ohm) were designed as high performance bass and midrange units for very compact monitors and high-end hi-fi speakers. The only difference between WF120BD05 and WF120BD09 is the shape of the mounting flange of the frames. WF120BD06 and WF120BD10 differ in the same way.
Features
Balanced Drive motor structure for optimal drive force symmetry resulting in largely reduced even order harmonic distortion
Copper cap on center pole to reduce voice coil inductance and to minimize variations in voice coil inductance as a function of voice coil position
Cone made of a new paper/glass fiber mix with improved consistency and stability
Rigid die cast alu chassis with extensive venting for lower air flow speed reducing audible distortion
Vented voice coil former for reduced distortion and compression
Vented center pole with dual flares for reduced noise level at large cone excursions
Heavy-duty black fiber glass voice coil former to reduce mechanical losses resulting in better dynamic performance and low-level details
Large motor with 1¼” voice coil diameter for better control and power handling
Built-in alu field-stabilizing ring for reduced distortion at high levels
Low-loss suspension (high Qm) for better reproduction of details and dynamics
Black motor parts for better heat transfer to the surrounding air
Conex spider for better durability under extreme conditions
Gold plated terminals to ensure long-term trouble free connection
Specifications
power handling (continuous/programme) = 60 W
frequency range = 60-3000 Hz
resonance frequency fs = 48 Hz
impedance R = 4 Ohm
sound pressure level SPL = 87 dB (2,83V; 1m)
DC resistance Re = 3,2 Ohm
force factor BL = 4,1 N/A
voice coil inductance L = 0,087 mH
effective piston radiating area Sd = 54 cm2
effective mechanical mass incl. air load mms = 7,3 g
equivalent volume of compliance Vas = 6,2 l
total Q factor Qts = 0,4 (Qms=7,4, Qes=0,42)
voice coil diameter = 32 mm
maximum peak linear excursion vibration xlin = +/- 4 mm
