When I started installing car audio professionally in the late '70s, if you truly wanted high-quality sound for your audio system there were very few domestic speaker choices. Back then you had to go with European drivers to achieve these hi-fidelity goals. Since then many players have come and gone, both domestically and internationally, but some of the best sounding speaker systems still arrive from across the pond. This month I had the privilege of auditioning the Hertz Mille MLK 165 6.5" component system from Italy that retails for $999.
Impressions
Packaged in an attractive container with a high-resolution picture of the contents on it, an impressive looking pair of 6.5" woofers captured my attention. Featuring a cast aluminum frame with a four-bolt pattern, a curvilinear aluminum cone, a Butyl rubber surround and 36mm (1.42") voice coil, these aren't your average woofers. The motor structure uses a "high-density flux" ferrite magnet and employs a ventilated pole piece, while the cone configuration is unique in that it doesn't employ the traditional dust cap on cone assembly, but looks rather like the inside of an inverted ice cream cone.
The sides of the curvilinear "V-CONE" curve down to a point at its center for better off-axis response. The spokes of the frame are also minimal to reduce reflections that could go back through the cone and color the sound in the listening area. The voice coil ventilation slots have a screen over them to keep foreign objects out and the tensile leads are attached to the spider in four places to stop them from hitting the back side of the cone at extreme excursion. The included grilles are of the high-void-ratio type so as not to restrict the output of the woofers. All in all, these are some beautifully executed drivers.
The 28mm tweeters in this set are also unusual. They feature interchangeable rear chambers to adjust the "Q" of the tweeter. According to the manual, "The Small chamber increases the Q factor with a sharper frequency roll-off slope; the Big chamber provides a smoother slope with better low-frequency extension." The domes of these tweeters are made of "a mixture of cotton and silk in a controlled percentage with a double-waterproof processing." The motor structure of the ML28 tweeters features a double neodymium and iron magnet with a low carbon content that was specially developed for this transducer. The tweeters come with mounting provisions for surface, flush or naked mounting in a factory location. The only thing I'd change is the color of the silver grilles - black would look better in most vehicles.
The crossovers are impressive too. They employ a circuit that Hertz has dubbed HFC (High Frequency Contour). When activated, this circuit contours the high-frequency response for the left and right channel tweeter for either listening position. This is stated to cure the acoustical anomalies in typical installations caused by different path lengths and tweeter angle. Very robust in their construction, the crossovers feature four levels of tweeter attenuation in 1.5dB increments from 0dB to -4.5dB, settable with what Hertz calls "Easy Jumpers" - a solid bar with a nice little plastic handle on them to make handling easier. Also using the same adjusters are adjustments for the HFC and to select whether you want to use the crossovers in a standard or a bi-amp configuration. Hertz uses poly caps, a tweeter protector and large-gauge inductors along with sand resistors for precise filtering and protection. The wire connections are made via an insulated barrier strip on one end of the housing that will accept up to 10-gauge wire. All this is neatly displayed under a smoked plastic cover.