MartinLogan ElectroMotion ESL X Loudspeaker Practical Hybrids

Practical Hybrids

If the ideal driver is entirely weightless then the electrostatic principle gets the loudspeaker designer fairly close, albeit with a host of technical challenges. MartinLogan has been developing this technology since its inaugural CLS prototype seen at CES in 1982 – employing a 'cling film' thickness (about 12µm) conductive membrane stretched between two highly charged, perforated steel stators. Then, as now, the membrane was positively polarised and pushed and pulled in sympathy with the applied audio signal. Reproducing deep bass remains tricky, however, for as the sound wavelength exceeds the size of the membrane there's a progressive cancelling of rear and front output.


In short, the bass rolls away very swiftly, as audiophiles discovered when Quad launched its seminal 'full range' electrostatic back in 1957. Arthur Janszen was ahead of the game with his smaller Model 65 electrostatic in 1955, as this was often partnered with Acoustic Research's AR1, complete with 12in woofer, to flesh out the lower octaves. MartinLogan's 1983 Monolith was a fused electrostatic/moving-coil loudspeaker and the brand has continued with this hybrid theme right up to the flagship Neolith [HFN Jul '16] and EM-ESL X of today, the latter with dual 8in woofers. PM

Lawrence, KS, US
Supplied by: The Professional Monitor Company Ltd, UK
01767 686300