The 12MB777 is a very high sensitivity (101.5 dB 1W/1m) midbass driver with high power handling capabilities. It can be used as either a bass/mid driver in compact 2-way reflex enclosures or as a direct radiating or horn loaded, dedicated midrange driver, in multi-way touring and fixed installation concert and arena systems. Its curvilinear paper cone made from a special high strength wood pulp, has been designed to achieve the best possible linearity within its intended frequency range and to control bell-mode resonances around the cone circumference. The cone is carried by a multiroll suspension formed of a linen-like material, which is more resistant to aging and fatigue than traditional materials. The 75 mm diameter state-of-the-art voice coil is similiar to those fitted to our top-of-the-range 18" and 15" models but it is wound with aluminum wire. It employs our Interleaved Sandwich Voice coil (ISV) technology in which a high strength fiberglas former carries windings on both the outer and inner surfaces to achieve a mass balanced coil. This results in an extremely linear motor assembly with a reduced tendency for eccentric behavior when driven hard. The excellent performance capabilities of this loudspeaker are further enhanced by the Double Demodulating Rings (DDR) designed to dramatically reduce the intermodulation and harmonic distortion and improve transient response. The magnetic structure has been optimized using FEA CAD resource, maximizing the flux density in the voice coil gap. Voice coil cooling has been achieved by incorporating airways between the chassis back plate and the top plate of the magnet, allowing heated air from the voice coil and gap to be channeled away and dissipated by the chassis basket. Due to the increasing use of high power audio systems at outdoor events or in marine environments, the ability to perform properly under inclement weather conditions is a key feature in Eighteen Sound philosophy. Hence, an exclusive treatment has been applied to the cone giving it water repellent properties. In addition, another special treatment has been applied to the top and back plates making the transducer far more resistant to the corrosive effects of salts and oxidization.
Mounting and Shipping Info
Nominal Diameter300 mm ( in)
Nominal Impedance8 Ω
Minimum Impedance5.7 Ω
Nominal Power Handling1450 W
Continuous Power Handling2600 W
Frequency Range60 - 5000 Hz
Voice Coil Diameter75 mm (3.0 in)
Woofer Cone TreatmentWeather protected
Recommended Enclosure50.0 dm3 (1.77 ft3)
Recommended Tuning55 Hz
Resonance Frequency49 Hz
Vas101.0 dm3 (3.57 ft3)
Sd531.0 cm2 (82.31 in2)
Overall Diameter315 mm (12.4 in)
Bolt Circle Diameter296 mm (11.65 in)
Baffle Cutout Diameter282.0 mm (11.1 in)
Depth147 mm (5.79 in)
Flange and Gasket Thickness16 mm (0.63 in)
Net Weight8.0 kg (17.64 lb)
Shipping Weight9.0 kg ( lb)
Shipping Box332 x 332 x 184 mm (13.07x13.07x7.24 in)
2 hours test made with continuous pink noise signal within the range Fs-10Fs. Power calculated on rated minimum impedance. Loudspeaker in free air.
Power on Continuous Program is defined as 3 dB greater than the Nominal rating.
Applied RMS Voltage is set to 2.83 V for 8 ohms Nominal Impedance.