Lets continue reviews of headphones of KEF and look on new M400 monitor model; manufacturer stays true to itself and from real technical characteristics names only following facts : 40 mm drivers are built into them ( they would have been set larger drivers for Hi-Fi basses reproduction ) and they are moved by neodymium magnets. And keeps silence about their : reproduceable sounds frequencies range, sensitivity, impedance, signal to noise ratio and maximal power input. Also it tells fairy-tales about “unique” “technologies”, that are built into them, which technical sense ( its existence is under big doubt ) is known only to manufacturer itself, and asks 250 USD for this device. This is a classical example of marketing money pumping from customers with use of Placebo effect. So, these headphones are not recommended for purchase and it is better to buy more than 2 times cheaper professional studio monitor headphones, which will surpass this device in all respects, or 5 – 7 times cheaper high-quality consumer monitor headphones of Sony, Philips and other manufacturers with known technical characteristics, which the most likely also surpass ones of this model.