Lowther PM3

An 8 inch twin cone loudspeaker of radically new design the PM3 was especially developed for use in the Lowther TP1 corner enclosure. Possessing one of the largest magnetic structures in use on loudspeakers today, it uses a powerful field to provide phenomenal efficiency over the full audible range.

The two cones-constructed of special material - operate from a single voice coil and divide the audible spectrum. True mechanical crossover permits smooth transition of lows and highd in proper phase and balance without any dips at the crossover frequency.

An outstanding contribution to the performance of the PM3 is the Stabilizer, a (non magnetic) shaped continuation of the center pole partially filling the space inside the tweeter cone. Providing air loading to the cone, it uniformly disperses the frequencies in the high and mid-ranges.

The contour between the Stabilizer and inner cone also forms a short horn for emission direct from the voice coil of very high harmonics and overtones.

The main cone surround is plastic foam. Energy not radiated or absorbed by the cone will reach the periphery and be absorbed in the foam, damping cone resonance in the middle and high frequency ranges. In the bass, because it can stretch, it permits large movements without sudden restrait, minimizing distortion in this range. The rear suspension is also foam, thus preventing reflection at both cone anchorage points.

The voice coil is of aluminum wire, for lightness, and is would half inside and half outside the voice coil former. This form of construction - much stronger than the normal form - makes it impossible for voice coil and former ever to separate under extremes of mechanical stress or temperature.

Forming the heart of the TP1, the PM3 makes an outstanding contribution to the uniformly high efficiency and superior performance of the reproducer.

Specifications

Frequency range: 20 - 22,000 Hz

Gap Flux: 22,000 Gauss

Power Rating: 25 Watts

Impedance: 16 Ohms

Weight: 10 kg