Tang Band W4-656SC 4" Shielded Driver

The Tang Band W4-656SC is a four-inch shielded full-range driver, and both halves of that description matter. Being full-range, it covers 65 Hz to 12 kHz from a single cone, so it can be used with no crossover at all: no filter components in the signal path, no phase discontinuity in the middle of the vocal range, and a genuine point source over most of the audible band.

Being magnetically shielded, it can be mounted close to equipment that objects to stray magnetic fields. This was originally a requirement for centre channel speakers placed on or near cathode ray tube televisions, and it remains useful today for near-field monitors sitting beside disc drives, sensors, instrument panels and studio equipment.

The parameters describe a well-behaved small driver rather than an extreme one. Sensitivity is 88 dB at 2.83 V / 1 m, respectable for the size, with a nominal 8 ohm impedance, 6 ohms DC resistance and a low 0.126 mH voice coil inductance, the last of these helping the driver stay clean at the top of its range. Free-air resonance sits at 65 Hz, total Q at 0.33, equivalent volume at 6.32 litres and continuous power handling at 25 W, with 3.4 mm of linear excursion from a 57 square centimetre cone.

A total Q of 0.33 with a 6.3 litre Vas points naturally towards a small sealed enclosure. Expect the bottom octaves to need help from a subwoofer, and remember that with any full-range driver the listening axis is critical: the top end narrows considerably off axis, so aim the driver at the listener.