PMC Loudspeakers XB2S-A

The PMC XB2S-A has a Transmission-line design with 12 inch radial woofer. Double veneered MDF cabinet; Crossover/Amplifier required.Power handling 800 W; FR 25 Hz-400 Hz; sens 91 dB SPL/W/m; imp 4 ohms.
15 x 34 x 21 inches; 108 Lbs

Transmission-line designWhen we looked at the demands for greater low-frequency extension from smaller and smaller cabinets we felt that what was needed was not available from either reflex or closed box designs. The driver is mounted at the mouth of a long tapered line, damped with absorbant material. The line absorbs the rear output of the driver through the aerodynamic drag of the fibres in the damping material. At very low frequencies the fibres move as one with air, the attenuation reduces and the port at the far end of the line begins radiating as another piston. The drivers excursion is then progressively controlled as the frequency is lowered. Unlike the reflex design, this control is maintained for over an octave, with the response rolling gently away as in the closed box system.