The Legend That Is Mille

Keep the noise down!

The Legend That Is Mille

The Hertz Mille line of reference car speaker products has been around since 1999. On the introduction of version two some seven years ago, I was lucky enough to have a pair of the entry-level MLK 165.2s fitted to my Vauxhall Vectra estate (see issue 1 of Driving Sounds Magazine). They served me well until last year when the car needed to be replaced. The Milles were still performing very well and the lucky new owner of the car still enjoys listening to them.

At the time they were fitted, I remember being quite blown away when hearing them in a test rig being used for listening tests by the designers. When they finally made their way into my car I was just as impressed - testament to the accuracy of the listening room the designers have in Italy where they were developed. It was with just a little trepidation that I received the news that the new designs have grown the appendage “Legend” to their name. How, reasoned I, could they be considered legendary when they were brand new? Perhaps, they were simply a facelift of the originals and were designed to replicate the sound? In which case, the point in producing them could only be related to lowering production costs and that would be both uncharacteristic of Hertz and very disappointing.

I have fondled, stroked and squeezed these beautiful beasts and if they are simply a face-lift then cosmetic surgery has come on quite some way since Joan Rivers sadly passed away. I am privy to a great deal of technical data from Hertz relating to the design of their products and I can assure you all that inside, they are not only an evolution but almost a revolution when compared to their predecessors. In fact, so different are they, it is difficult to know how to compare without getting unnecessarily technical about cone geometry, shorting rings, spiders, baskets and all the other important elements that can affect the performance of a speaker. Instead, I will simply examine a few key design features.

Since 2005, Hertz have been employing techniques and equipment in speaker design developed by eminent thought-leading physicist, Prof. Dr. Wolfgang Klippel. Mille Legend has undergone a great deal of work in every physical and electrical parameter using Dr. Klippel-approved Finite Element Analysis which allows designers to “try” different materials and technologies on an intrinsic design to accurately predict what effect these changes would have on the final design. Through painstaking research just about every element has been re-engineered. Woofers and subwoofers use patented V-cone technology. V-Cone relates to the profile shape of the cone. This is used as it adds rigidity to the cones without adding weight. The aim is to have a cone that moves as much air as possible while holding its shape. The ultimate goal is to make a “perfect piston”. In Mille Legend, the geometry of the cone has been improved and a “boundary-free” cone surround introduced to allow greater travel or excursion and yield an increase in cone area and thus sound pressure level, while keeping the same outer diameter. The cone itself is slightly shorter to keep it more compact but this has also improved linearity due to its ability to hold shape at high levels. The paper cone has been treated with a “secret recipe” of chemicals offering further stiffness whilst maintaining the legendary natural openness enjoyed by current Mille owners. The new cone shape has also, according to Hertz, improved dispersion or width of radiated sound. Wide dispersion is vital when listening in the car where a driver sits very close to the right speaker (in England anyway!) and relatively far away from the left while both speakers are unlikely to point toward the listener’s ears! To complement the changes to cone geometry and surround material, the cone suspension system, also known as the spider, has also been heavily reworked. One of the most important characteristics to benefit from this redesign is dynamic compression. This phenomenon negatively affects the ability of a speaker to accurately interpret highs and lows in music and is very important when listening to fine details which add greatly to listening pleasure.

Subwoofers benefit from a brand-new 100mm voice coil with the windings fixed to both the inside and outside of the former. This offers much more effective and regular cooling resulting in a more linear performance and lower distortion as well as drastically reduced dynamic compression. Magnetic flux and therefore power and efficiency are increased by mounting the magnets on the inside of the voice coil rather than the outside. Due to increased power, the whole chassis has been engineered for additional rigidity, as has the new six-spoke anti-resonance aluminium basket. Further cooling measures are included in the design of the new Mille Legend by way of eight vent holes in the base plate ensuring that heat is efficiently dissipated from the voice coil.

New for this range is the introduction of the increasingly popular 180cm woofer, a size much loved by German car manufacturers amongst others! – This opens up these cars to the fitting of Mille where previously a diameter reduction ring would have been employed, cheating the car owner out of some additional bass extension!

Mille tweeters have been considered the benchmark for system builders for many years and designers had to take great care that any development work carried out truly enhanced performance without removing any of the previously enjoyed characteristics. As with woofers and subwoofers, the goal was to reduce distortion while increasing efficiency and linearity. I am told this has been achieved by a combination of motor assembly improvements and adjustments to the geometry of the Tetolon dome. However, another desirable improvement was to be gained by optimising the rear chamber of the tweeter resulting in a lowering of the frequency response to 900Hz. This allows the tweeter to reproduce lower frequencies, offering an overlap with the upper frequencies of the woofer. This is important to ensure a smooth transition between mid and high frequencies. In theory this should provide a more stable phase characteristic.

Project Manager, Luca Girotti told us; ”We used three main listening tests when developing Mille Legend: in the car as a real-world situation, in the listening room to make critical evaluation of each single driver, and in a display stand to simulate being in a shop, demonstrating the system to a customer.

One day we were performing the latter in our testing facility and playing music really loud on the 6-inch ML 1650.3 with a track rich in bass content. The room is sound insulated so as not to disturb offices upstairs, but at a certain point of the test we had someone knock at the door. We stopped the test, the door opens, and a lady asked "Guys, would you please at least shut-off the sub as we're having a meeting upstairs!" As the door closed we looked at each other with the big smiles on our faces - The sub wasn't playing at all, it was just the ML 1650.3 woofer!”

At the time of writing I have only managed to hear these speakers briefly in a car that was not quite finished. It was the 2-way MLK 165.3 system with a supporting High Energy HX 250 subwoofer all driven by Audison Prima amplifiers (passive fronts run from a bridged AP 4.9 and subwoofer driven by an AP 1). I threw some of my test tracks at them anyway including: “The Wheel” by Sohn, Kelly Joe Phelps’ “The House Carpenter”, and “Lucille Has Messed My Mind Up” by Frank Zappa. Bass was a little overwhelming and it was, I admit, difficult to tell where the woofer ended and the subwoofer took over. At the high-end however, I was struck by the openness, and pinpoint precision in which the system handled cymbals and other percussion elements. Mid-bass was full of energy albeit slightly overwhelmed by bass due to lack of set up, but it all sounded just a tweak away from perfection to me. I look forward to bringing you more comprehensive results once I get the chance to hear them in a more perfect environment. However, even this briefest, less than perfect glimpse has me very excited about this latest range of legendary speakers.

Luca’s Top Five Driving Sounds for Mille Legend listening.

Get Lucky - Daft Punk

Mack The Knife – Michael Buble

Hotel California – Eagles

Don't Know Why - Norah Jones  

Una Mattina - Einaudi