The VM753 is a 16 ohm version 3” (75mm) diameter dome unit loaded by a short, front mounted horn. It uses a lightweight single layer, round wire copper coil slightly longer than the focussed magnet gap to allow for high excursions at the lower end of its operating range. The dome and surround are critically doped for smoothness and consistency of response, a second, rear surround maintains coil stability. An FEA designed magnet system uses a 155mm ceramic magnet for high efficiency and is solidly fixed to a painted, aluminium chassis. The termination braids are hidden inside the unit and are not visible, connection is by 6.4mm (0.25") spade terminals allowing soldering or push on receptacles. The entire dome/coil assembly is built onto a replaceable ring that accurately self locates so allowing easy field replacement. The unit is intended for rear mounting, M5 threaded inserts are incorporated in the flange for fixing screws.