Leak unveils Sandwich 150 and Sandwich 250 speakers

Some 63 years after its debut, the Sandwich 150 and Sandwich 250 take the blueprint established by the original Leak speaker. Debuted in 1961 to tackle the problem of how to make driver cones both very light and extremely stiff, Leak claims its sandwich cone construction is as relevant now as it was in the Sixties.

The Sandwich 150 and 250 speakers update the concept using modern materials, design technologies and manufacturing techniques, incorporating a stiff aluminium skin for the outer surfaces (where the stresses are greatest) bonded to a core of aircraft-grade polymethacrylimide structural foam.

The Sandwich 150 and Sandwich 250 are both standmounts, the former a two-way design with a height of 415mm and the latter a larger three-way model standing 655mm tall.

The Sandwich 150 incorporates a 30mm textile-dome tweeter and a mid/bass driver with a 170mm Aluminium-Foamcore Sandwich cone, while the Sandwich 250 combines the same tweeter with 280mm bass and 108mm midrange drivers, both of which feature Aluminium-Foamcore Sandwich cones. The treble unit includes a damped rear chamber to absorb the output from the back of the 30mm dome, isolating it from the rest of the loudspeaker and reducing its resonant frequency to below the crossover region. Sensitivity is quoted as 86.5dB and 88.5dB respectively with nominal impedance of 6ohm.

The cabinet walls are formed from an outer layer of MDF and an inner layer of high-density particle board – the different densities of these materials used to help scatter panel resonances – enhanced by a filling of special glue that bonds the layers and provides resonance-damping properties. This is combined with precisely positioned spot-bracing, together with a specific front-rear brace that echoes the design of the original. The cabinets are dual-ported at the rear, augmenting the speakers’ bass response. The new cabinets also take design cues from their forebears, finished in a walnut wood veneer complemented by aluminium driver trims and an aluminium insert around the edge of the front baffle. The company says the protective grille further enhances the speakers’ classic appearance while maintaining the highest acoustic standards.

Leak has additionally created a dedicated stand for the Sandwich 250, constructed from high-carbon steel with an acoustically damped, walnut-veneered base and stainless-steel spikes, plus spike seats for hard floors. The stand has been specifically designed to ensure that the Sandwich 250 is elevated to the ideal height for seated listening and manages the unwanted effects of vibrations and sound reflections. It costs £2,300. The Sandwich 150 measures 415 x 250 x 290mm (WxHxD) and is priced at £1,000 per pair. The Sandwich 250 is 655 x 370 x 300mm at £1,100 per pair.

Available to buy now, you can find out more about the Leak Sandwich 150 and Sandwich 250 speakers here.