Before I did any listening, I exercised the woofer for a few hours, and let it normalize again overnight. This isn’t a compulsory step, because in your car the woofer will obviously break-in as it’s used for the first few days or weeks, but here in the test lab, we do everything we can to maintain consistent and accurate results, so we exercise all speakers before doing any evaluations. Because I had the opportunity at CES to listen to the man who engineered the woofer, I knew that the Hertz SX 300D would be best suited to a smaller size vented enclosure. It was a good thing too, because while the owner’s manual will show you how to configure the jumpers and wire up a dozen or so woofers, it mysteriously gives no recommendations whatsoever for an enclosure size or type.
The smallest vented box I had on hand was 1.25 cubic feet, so I figured we’d give it a go in that. After selecting a series wiring configuration for a final impedance of 4 ohms, and mounting the woofer in the enclosure I set the amplifier crossover to 100Hz, with a -24dB per octave slope.
Frequent readers of my speaker reviews know that my musical tastes are pretty diverse, and I’d picked out some different tracks to test the mettle of the Hertz woofer. Because this is a woofer designed to play low and loud, I began with a track from Yello’s Essential CD, “Oh Yeah”. The hype about this woofer playing low and loud is no joke, and that track proved it. Moving on to a few other favorite bass SPL tracks from Bass Mekanik and others, I was convinced that the SX 300D would definitely play loud, and handle a lot of power.
But let’s not forget that its alternative claim to fame was also supposed to be good sound quality, so I switched musical gears and broke out my audiophile tracks. I listened to a bunch of material from DMP, Chesky, and Sheffield Labs. Once again, the woofer pretty much lived up to the story I’d heard at the show, and in fact it did sound pretty darned good for a subwoofer designed for SPL. The SX 300D had tight, fairly well-controlled bass with a lot of punch and impact. It had a touch of ringing that maybe wouldn’t be there in a more compliant design, but then again it’s that stiff suspension that allows it to handle the 800+ watts I fed it with no complaints whatsoever. And thanks, at least in part, to the intelligent use of a paper cone, subtleties like resonances from plucked strings, and augmented chords were easily reproduced too. Make no mistake, this woofers primary focus is to play low and loud, but when the mood strikes, it’s a pretty decent compromise for the sound quality crowd too.
With my listening completed, I brought the woofer into the test lab and made some measurements. As I expected, the published parameters for the woofer are very close to what I measured, and the in-box curves also came out pretty much as expected. As you can see from the SPL graph, this is a subwoofer that can really get the job done.
The Hertz SX300D woofer sort of reminds me of a 1960’s muscle car. Somewhat like my old ‘70 Hemi Roadrunner, all most people had to do was see the Hemi badge, and they knew what they were up against. Like that car, the SPL Show series of subwoofers are not for the faint of heart or those who are timid about their sound. Just like my Hemi, all you need to do is crank it up one time, and anyone within earshot will know you’re serious! And while no subwoofer can satisfy every single purpose or customer, this one is purposefully made for anyone who appreciates loud, deep, authoritative bass in their car. But unlike some other woofers that were designed and restricted with a focus on SPL contests, you can actually play real music with this impressive subwoofer, and enjoy its sound quality performance too.