Bookshelf Speakers

Emotiva Airmotiv5 Powered Studio Monitor Speakers


Design of the Emotiva Airmotiv5 Powered Studio Monitors

Like the other Emotiva products these speakers show no skimping on engineering effort. The airmotiv's have not one but two built in amplifiers. Both the low and high frequency amps are each rated at 50W. The crossover between them can be adjusted somewhat via a 'tilt control' (high frequencies) or 'shelving control' as (for the low frequencies). The available selections are flat or plus or minus 2 db for the tweeter and flat, -2db and -4db for the woofer. The woofer is ported via a large, flared rectangular port at the top rear of the speaker. Fit and finish is top notch though the one available color is studio-ready flat black. Certainly unobtrusive and cool-looking but there are some more decorative choices available in this rapidly expanding market segment. Volume is controlled via a small knob on to the lower right of the woofer. A lighted ring (in 'Emotiva Blue') surrounds the knob which can be flush with the front baffle or made to protrude by about ¾ of an inch by pressing it. Power is controlled by a rocker switch on the back, the power cords are detachable. Leaving the best for last – the most striking feature on the airmotiv line is the tweeter – a folded ribbon. This innovative technology is not new, generically called an 'Air Motion Transformer' it was first used commercially in 1972 by ESS.

These tweeters are enjoying a bit of a renaissance of late. My theory is that this is simply due to the large number of players in the hifi industry, each of which is striving to differentiate themselves from the others and provide more value to us hifi nuts. An Air Motion Transformer works very efficiently as the squeezing action of the folds pushes air out at a rate 5 times that of the motion of the membrane itself. A magnetic field created by fixed magnets at the top and bottom of the tweeter along the signal current passed through the membrane create the motion. The disadvantages are a dipole radiation pattern and the temptation to have a relatively low crossover frequency (because the AMT can handle it) which exacerbates the dipole issue and puts the crossover right in the sweet spot. The airmotiv's avoid those issues by putting the crossover 'up there' at 2700 Hz.