GB Series subwoofers are designed for high power handling and optimized to provide superior low frequency extension from a wide range of sealed and vented enclosures.

A copper inductance-reducing pole piece cap also reduces distortion and extends the range of flat response well into the midbass.

The GB12D4 includes a vented, cast aluminum basket, dual 4 ohm voice coils and a convenient switch to select a 2 ohm or 8 ohm configuration

• Treated Paper Cone
• 3” (75 mm) Voice Coil on Fiberglass Former
• Dual 4 Ω Voice Coils
• Impedance Selection Switch
• Copper Inductance- and Distortion-Reducing Pole Piece Cap
• Extended Pole Piece
• Flared Pole Piece Vent
• Dual Ferrite Magnets
• Machined Back Plate
• Proprietary Vented Cast Aluminum Basket
• Tinsel Leads Stitched to the Spider
• Flat, Progressive Nomex® Spider
• Nitrile Butadiene Rubber Surround
• Screw Terminals

Specifications:

• Nominal Impedance: 2 or 8 ohms
• RMS Power Handling: 500 W
• Peak Power Handling: 1500 W
• Frequency Response (-3 dB): 22 Hz – 180 kHz
• Sensitivity (2.83 V/1 M): 92 dB (2 Ω configuration)
• Recommended Amplifier Power Range: 100 W – 1000 W

Dimensions:

Enclosure Performance (See Owner’s Manual For Details):

Sealed Enclosure Volume: 28.3 liters (1 ft³):

Vented Enclosure Volume and Tuning: 42.5 liters (1.5 ft³), 33 Hz:

Thiele & Small Parameters:

• Revc: 2 Ω or 8Ω
• Levc@1kHz: 0.58 mH (1 Ω configuration)
• Sd: 510.7 cm2
• Mmd: 177 g
• Mms: 184 g
• Cms: 171 µM/N
• Vas: 63.7 liters
• Fs: 28.4 Hz
• BL: 11.47 TM (1Ω configuration)
• Qms: 8.82
• Qes: 0.52
• Qts: 0.49
• Xmax (1-way linear): 19 mm (11/16”)
• Basket Displacement: 4.17 liters (0.147 ft3)

GB Subwoofers Owner’s Manual