SB Acoustics SB12CACS25-4 4'' ceramic woofer

Features:

• Vented cast aluminum chassis for optimum strength and low compression
• Ceramic cone
• Soft low damping rubber surround for improved transient response
• Shorting ring in motor system for reduced distortion
• Non-conducting fibre glass voice coil former for minimum damping
• CCAW voice coil for reduced moving mass
• Long life silver lead wires
• Vented pole piece for reduced compression

Specifications:

• Nominal Impedance 4 
• DC resistance, Re 3.1 
• Voice coil inductance, Le 0.26 mH
• Effective piston area, Sd 50 cm2
• Voice coil diameter 25.4 mm
• Voice coil height 15 mm
• Air gap height 5 mm
• Linear coil travel (p-p) 10 mm
• Magnetic flux density 1.07 T
• Magnet weight 0.40 kg
• Net weight 0.92 kg
• Free air resonance, Fs 51 Hz
• Sensitivity (2.83 V / 1 m) 88 dB
• Mechanical Q-factor, Qms 4.89
• Electrical Q-factor, Qes 0.33
• Total Q-factor, Qts 0.31
• Moving mass incl. air, Mms 6.1 g
• Force factor, Bl 4.3 Tm
• Equivalent volume, VAS 5.7 liters
• Compliance, Cms 1.60 mm/N
• Mechanical loss, Rms 0.4 kg/s
• Rated power handling* 30 W

* IEC 268-5, T/S parameters measured on drive units that are broken in.