Hertz HX250

Ten inch woofer in single voice coil configuration (although the range has dual VC models) with very high power handling capability. It has a lot of bits and pieces supplied with it, including the moulded rubber gasketing which is designed such that the woofer may be easily mounted with the magnet assembly outermost. The Hertz HX250 has a very high standard of build and uses Allen key headed grub screws to secure decently fat speaker cables in angled terminal blocks that are well marked and feel solid. The manual is excellent, giving details of box construction and best practise (stuff such as ensuring that there is at least 30mm between the back of the subwoofer driver and the rear panel to allow the rear magnet port to breathe unimpeded and the best thickness MDF to use and even how to effectively damp the inside faces of the enclosure.) Unusual in that the reversibility includes the top plastic trim piece as well as the softer rubber injection-moulded gasket that arrives as part of the extra bits kit. You remove this plastic trim to reveal the ample mounting hole provision in the cast chassis. The subwoofer is clearly designed to look good in reverse mount.
– Frequency response: 34Hz to 800Hz
– Power Handling: 450w RMS (900w max)
– Polypropylene injected cone with Mica for added stiffness
– Oversized super-duty foam top roll surround
– Parabolic indented dust dome
– Die cast Aluminium chassis
– Large moulded rubber gasket
– Single 4 Ohm voice coil
– Angled Allen headed grub screw terminals
– Voice Coil Diameter: 2.5 inch (65mm)
– Mounting depth 150mm- Double high flux density Ferrite magnet
– Efficiency: 89dB 1w/1M
– Xmax 14mm electrical, 23mm mechanical
– Fms: Not quoted
– Qes: 0.49
– Qms: 4.70
– Qts: 0.44
– Vas: 24.04 Litres
– Mass 9.5kg
– C/W Sticker, fixings, Allen Key, manual, start up guide, moulded rubber gasketing and plastic gasket
Review by Adam Rayner
The Hertz HX250 was mounted into a decently solid MDF sealed enclosure (as a tuned enclosure may be designed to go with any single driver, I always tend to review in sealed boxes. These offer output to the deepest the speaker driver’s suspension will drop to but no extra advantage tuned to the woofer’s Thiele Small parameters. It’s fairer that way.) and plugged it in with thick cable internally and externally (I upgraded the enclosure’s internal cables to StreetWires 12Ga) and on the other end was a new Class GH Vibe BlackBox 5 monoblock bass amplifier.
To start with, it was clear that this is one serious piece of bass engineering and that also it is best used for a good while before it could be declared to be run in. For, just like shoes, the squashy bits (not the cone, just the suspension to it) are made so as to bed in and soften to a certain level over time. In a speaker’s case that means becoming a good bit faster and more able to move. It’s also why a speaker declares an electric Xmax or maximum travel of cone, as well as a mechanical one. That’s how far the speaker cone will wobble under its own volition, beyond the shove of the coil in the magnet gap. As the suspension gets broken in it’ll go further and so will even change in sound, becoming warmer and sweeter. This woofer starts off from a very good place and yet because it is a very high power design, it has to sacrifice some initial from-new efficiency and snap. Rated at a nutty 450w proper RMS, it is a half kilowatt continuous product. However, the Vibe BlackBox five is a bit of a Pepperami and has way more power than that, so like some kind of twisted S&M audio nutter, I took it just a bit far into it’s just about handling it zone and then wicked back a tad.
I played with the subsonic filter and the bass boost frequency as well as with the crossover point. It liked it low and clean and yet had nary a problem with tracking a flexing bass line with throbs and swells, right in the middle of it giving it serious drive already.
If pushed too far it would purr a little and yet is made so tough that you would have to be a moron not to be able to tell. This makes it just short of Weapons Grade as it has a serious slice of power despite being a small diameter of piston and was able to shake the room (and the foundations) and drop impressively low. Made for power rather than flex, the stated not-too-low bottom cut-off frequency is a bit high in this size of HX driver which meant that despite all the muscle and grip, it just didn’t get all the way as low down as I knew the material did and certainly not as low as some tens I have heard that are made to drop rather than go loud too.
The SPL the thing could reproduce with clean purity was impressive. If you needed but one woofer and wanted it to look good and to really rock but also suffered from snide SQ urges, with the odd bit of Techno around the edges, then this woofer could do it all. It isn’t really a Bass CD or Slow Jam type product but if you want fast tight bass for what is a very keen price (you would have been looking at £300 easily for this much woofer even as long ago as two years) and with the ability to really throw some power down on occasions, then this is a real contender.
I love the branding and the attention to sexy build quality and I am impressed by the detailed manuals supplied with the product. The best bit is how keen the makers are to present their butts to the world. A set of these, some innies and some outies, looks the nuts and will be full on. Just one on it’s own can be part of a system called ‘top end’. You’d just have to partner it with good kit.
A true SQL woofer and that means ‘Sound Quality (yet) Loud’
‘Nuff woofed.
Sound Quality 8.0
Build Quality 9.0
Power Handling 9.0
Efficiency 7.0
Value For Money 9.0
Overall rating 8.4