JEM M4a monitor

High Performance Mini Monitor

The M4a is the first in a series of loudspeakers featuring 4,7 inch woofers. The M4a is modelled to my Refence monitor M7s with many similar techniques. The most recognizable are the SEAS Excel magnesium woofer ,the facetting of the solid wooden cabinet and the bass port made of inert industrial aluminium. Many who listened to the M7s Reference will recognize a similar acoustic signature despite its size being only a fraction. The M4a has a surprising full-bodied sound and extended frequency range up to 37 Hz. But that is not even the best part. The capacity to deliver a enormous spacial stereo image is literaly second-to-none.

High Quality components

Despite the substantial price and size difference with its larger brother, many highstanding features are still implemented. While the filter of almost all competing loudspeakers in this price range have only cheap electrolyte and metallized capacitors, the M4a utilizes multiple costly but high performing Tinfoil cap's. Tinfoil capacitors such as the KPSN sound very dynamic and transparant due to their seperate conductive foil and heavy weight. Metallized capacitors such as MKP, PPM or MKT have, due to their ultra thin conductive layer, much higher losses. Usually around 10x (!). In practice this results in “smearing” effects, loss of detail, loss of “air”. Electrolithic capacitors, (still used in many hi-end loudspeakers by many well known brands!), are NEVER used in JEM loudspeakers. These are many factors worse due to their enormous losses and distortion. On top of that they degrade ever further over time because of electrolite evaporation.

Rigid cones act like a piston

The specially modified SEAS tweeter with Aluminium-Magnesium alloy dome delivers smooth and high resolution high frequencies. The woofer cone is made from machined Magnesium. Magnesium is a rigid and self-dampening material. The rigidity makes it follow the music signal very close and by that, delivering a vastly improved clarity and reduction of Intermodulation and Harmonic distortions. Like with all other JEM systems this model has a high standing woofer-tweeter integration.

Efficiency is relative high for its size: 85dB/1W. With a impedance minimum of 5,5 Ohm @ 400 hz it is a true 8 ohm system. So recommended amplifiers also include tube amps. Like with all other JEM systems, the M4a is optimized for use at close proximity to a back wall.