Surround Sound Speaker Systems

Hsu Research ULS-15 Subwoofer and HB-1/HC-1 MK2 Speakers


The Sound

I started this review with two questions. First, how would the Hsu magic translate from a ported to sealed box subwoofer? And second, what would a horn-loaded bookshelf speaker designed by a renowned sub guru sound like? There is always a risk with subjective listening tests, because if you are pre-conditioned to hear certain things, it can become a self-fulfilling prophecy. However, I have started a review expecting to “hear” a certain sound, and been surprised many times.

So with that disclaimer, the ULS-15 performed as I expected it would, meaning that, like all Hsu subs, it had clean, substantial output across the subwoofer’s frequency range. I also noticed, as with other sealed designs, a subtle difference in the sound. For example, the film Batman Returns (Dolby TrueHD) has plenty of low-end action coming from explosions, gunfire and the buffed-out Batmobile. With the ULS-15, transients were more pronounced, with a quicker attack and release than normally found in ported subs. To the listener, it can seem as if there is less output (even though I calibrate levels with all tested subs to match with the main speakers). I think what is happening is that, with a ported sub, the port-induced group delay means that the LF from the sub reaches the listener later than the high-passed upper harmonics coming from the main speakers, and likewise extends after the sound from the upper harmonics has dropped off. This creates a “fatter” sound, which the ear sometimes interprets as louder.

With music, the Hsu’s excellent transient response meant taut, focused bass. As mentioned above, Steely Dan’s Hey Nineteen from Gaucho (SACD), has a pulsing, dotted rhythm, anchored by Walter Becker’s bassline locked in time with Rick Marotta’s kick drum. The ULS-15 reproduced the punch-like sound of the kick drum, like you’d hear in a live performance.

While the ULS-15 subwoofer sounded as expected, the HB-1 MK2 bookshelf speakers wildly exceeded my expectations. The Hsu’s had amazing detail and precise imaging, at a performance level of speakers costing several times the HB-1’s $150 price per speaker. The HB-1’s distinguished the picked guitar and electric piano tinkling on Hey Nineteen, even though they occupied the same frequency space in the mix. There was no hint of the nasal, honking tone that sometimes plagues horn speakers. The soundstage was fine, although not nearly as dramatic as the overachieving detail and imaging produced by the HB-1’s. I did notice some lobing effects from the HC-1 when sitting off-center, likely due to the W-T-W configuration, but otherwise vocals were reproduced with no apparent timbral mismatch between it and the HB-1’s.