HERTZ MILLE 2000.3
Hertz’s outstanding engineers once again prove that small is beautiful… and can also be ultra-powerful.
Unsure how to put this delicately, so this is rather bluntly straight to the point; the Hertz Mille range went off the rails there for a year or two. Now as I commence buttoning up the flame suit allow me to place some historical context around such incongruous comments.
It started around ten years ago when Hertz was beginning to make serious inroads into the car audio market worldwide. Some audaciously stated Hertz was just a flash in the pan and that its popularity would promptly disappear along with its flamboyant orange packaging. Not to stand for such insolence Hertz struck back, developing the Mille range which not only spent the ensuing years decimating its competition, but became prove positive that Hertz was no Johnny-come-lately to the highend audio scene. This friends, is where things started to go a little pear shaped, as far as this author is concerned. The company rested on its laurels, releasing a new range of Mille components that, while acceptable, truth be told they were a shadow of their former glorious self. The result being that many people, this writer included, began howling like wounded lycanthrope about it. We fast forward to today where Hertz, never one to be frivolous and indeed one that listens to its constituents has rectified the situation creating a new Mille range. And it’s regal enough to bear the legendary Mille moniker once again.
SMALL YET POWERFUL
To accompany the Mille component speakers we reviewed in issue #3-2015, Hertz developed a pair of subwoofers to fill out the bottom octaves of the Mille range – an 8-inch ML 2000.3 and 10-inch ML 2500.3. We’ve chosen the ML 2000.3 for review because the Mille drivers are intrinsically sound quality oriented, and systems of this nature tend to not always require titanic-sized subwoofers. For example; did you notice there’s no 12- or 15-inch variant? However, that said, the ML 2000.3 is no weakling, on the contrary it has more colloquial muscle than many other subwoofers on the market, including meek imitations thrice its size.
Starting at the kinetic end; the ML 2000.3 features a 200mm diaphragm constructed from a base core of pressed-pulp resulting in a very natural sound. The upper and lower sides are then sealed and treated with a mineral powder coating which gives exceptional rigidity and terrific damping characteristics. Just pausing on the aforementioned subject; cone profile or shape, is something that many readers gloss over without giving it a second thought. Cone geometry has advanced in leaps and bounds over the years – it’s not just about brute strength. Of course, the ability to retain shape under duress is most important, but the actual physical profile of the cone is also paramount
to the diffusion azimuth and the projection of the sound forward of the driver. Hertz has spent countless hours getting the cone shape of all the Mille drivers just right, utilising its trademark-registered exponential V design to give superb strength and aural reproduction. This is not only within the subsonic regions but also the higher midbass regions too, to the tune where the ML 2000.3 can sound equally competent playing the subwoofer role all the way through to that of a serious midbass driver – something most subwoofers can only dream of.
Assuming that you’ll be running it in its intended role as a true subwoofer, you’ll no doubt desire some serious kick, and this equates to serious suspension. To that end the top edge is surrounded by a boundary-free IIR rubber surround which works in conjunction with the flat non-progressive rolled polycotton spider beneath. These allow the motor to move freely but with scrupulous control, within the densest magnetic fluxes created by the extraordinarily large neodymium magnet which has been optimized with FEA simulations aplenty and lives within the core of the structure. But the extravagance doesn’t end there. Working with this magnet is the central pole which contains a large aluminium shorting ring and together the motor moves with minimum distortion both radially and axially right out to its 23mm Xmax excursion. Now the best magnet in the world isn’t going to do much without being married up to an impressive motor within, ergo the former is a whopping 100mm item that’s constructed from TIL, a material made from a fibreglass base which offers the strength and weight attributes of Polyamide compositions but possesses the thermal dis- sipation qualities of alloys such as aluminium. The voice coil is a single 4-ohms multi-layer affair, comprising of twin copper-clad aluminium winds layered one on either side of the former in such a fashion to allow for uniform cooling of the entire coil, to the tune of it being able to handle over 700 watts continuously before the cooling system comes into question.
Seeing as I’m an inquisitive soul I thought to look further into the cooling system and to do this we need to start with the acoustically transparent aluminium frame, so selected due to its magnetically inert and anti-resonant properties. The black anodised basket features six web fingers and built into each of these are the venting intake holes. These large intakes feed cool air directly into the voice coil gap just below the spider and, once within, this zephyr flows up and over the voice coil gap before snaking its way into the centre for expulsion via the 25mm pole vent. It’s not just any pole vent either – one glance gives confirmation that it’s a derriere with a physiognomy rivalling a Kardashian. Constructed from a single gargantuan solid aluminium block, the back cap is meticulously machined and boasts an additional eight air vents with various facets to assist in air flow. Besides encasing the entire motor and magnet the end cap also extends down to provide for extra suspension overrun, giving the subwoofer a maximum power handling ability of over 1400 watts before bottoming out becomes of concern.
The Hertz logo is proudly displayed upon the back end while the terminals are smarty attached to the side. What’s also interesting about the overall backend design is that because the voice coil is large, diametrically speaking, it doesn’t have to be overly deep. This means that with a mounting depth of only 117mm you can have your cake and eat it too.
When talking smaller subwoofers and their associated enclosures many will pose the supposition that these drivers only handle higher frequencies, an assumption which is misplaced to state the least. More often than not the problem lies with the enclosure being the incorrect volume to return a desirable Q. With this in mind, we set out to model the perfect enclosure, being aware that Hertz recommend 10 to 17 litres sealed for optimum performance. It’s true that companies often undersize enclosure recommendations in order to harbour less warranty returns because the overly compressed air makes it harder to bottom the subwoofer out. However this impacts the enclosure Q, often sending it well over 1.0 and this is the actual reason why many subwoofers don’t appear to play very low. Hertz in its wisdom however has recognised that because the ML 2000.3 is a serious sound quality subwoofer, it’ll likely lend itself to an owner which exercises equal consideration in order to achieve a perfect Q. Our modelling returned an enclosure volume of 16.06 litres sealed and Q of 0.707, which is right on par with Hertz’s recommendation and this volume also offers a constant group delay of 4ms.
As someone who has sold and installed plenty of Mille subwoofers in the past, both the good and the not so, it was most captivating to see how this new one would stack up. It certainly looks up to the task, easily rivalling the original Mille subwoofers and looking for all the world like it will produce in spades. Interestingly, Hertz does not supply a grille as part of the package but it can be purchased as an option.
So how’d she go sonically? Well putting it mildly, it’s one extremely solid little performer. Indeed the primary thing that comes across even during its running-in process is that it’s a strong subwoofer, with a physical presence that commands the sound. This could easily be attributed to the colossal motor within, however, remember back to what I said about the cone profile too. The sub-bass that emanates from the ML 2000.3 is more than just a little hearty, especially given its deceptively diminutive dimensions and, thanks to the diaphragm profile, its sound protrudes well forward of the cone, thus allowing for it to be mated perfectly with your front stage no matter what the frequency. It’s also very accurate, with its transient speed and deceleration rate being superb. Of course a lot of this pertains to the amplifier employed but, that said, you don’t start with rubbish and end with brilliance.
When the second generation Mille subwoofers came out they were good, but alas nothing compared to the original. However, with this latest incarnation we’ve witnessed Hertz making a complete one-eighty, developing a new subwoofer range that makes both the previous and even the original look pale in comparison. Truly terrific stuff.