VTF-3 Good Sound Review [Archive] - HSU Research Forum (HRF)

Lwang

January 28th, 2004, 8:27 PM

They should be putting the TAS review that they had for the 1220. Instead of trying to keep track of all the reviews here and there on e-rags that nobody reads or ones that only care about boom/shake and SPL, place the one in which gets respects from many audiophiles and actually talk about aspects of the sub's sound characteristics

Here is a couple of those, TAS's and Audiophile Voice's reviews:

TN1220HO
Paul Seydor, The Absolute Sound, Issue 118

The Hsu Research TN1220HO is one of a line designed by Dr. Poh Ser Hsu, a native of Singapore who holds a degree in Civil Engineering from M.I.T. Deciding to pursue a long, passionate interest in music and sound, Hsu now manufactures subwoofers in Anaheim, California. The 1220 represents something of a rethinking of subwoofer theory and application. A 48-inch tube, 13 inches in diameter, houses a 12-inch woofer on one end and a 28-inch double-flared port on the other. The tube is made of 1/8-inch thick fiberboard – in other words, extremely stiff paper – stuffed with fiberglass and covered with black cloth. This “cabinet” weighs less than 32 pounds and can be carried under one arm. It is designed to be placed standing up on supplied spikes or, so help me, laid down on its side behind a couch (of which more later). As Hsu favors long speaker cables and short interconnects, the 500W amplifier/crossover is outboard and comes set at 91 Hz (appropriate for Quads, which the designer himself owns in the original version), but nine other settings are available on request. Linkwitz-Riley 24-dB/octave slopes are employed on both sides of the crossover.

So how does this thing sound? Starting with the crossover, like next to nothing at all, so transparent and characterless that, practically speaking, it’s almost impossible to tell whether it’s there or not. This superior transparency resulted in a subtle but unmistakable effect at the beginning of Dark Side of the Moon: the ticking clock emerged from under the beating heart fractionally sooner and with a slightly longer fade up. Allied to this transparency was a really amazing leap in dynamic range from the Quads. I cannot explain this except to suggest that perhaps the 24 dB/octave slope on the high pass filter requires even less work from the Quads below the crossover frequency than other designs with slopes less steep. On all the complex material, from Sinfornia Antartica to Pomp & Pipes, the Hsu/Quad combination cast the deepest and widest soundstage. The battery of tympani and snares that heralds the grotesque march of the dead in the Mahler’s Second (track 9) was hair-raising in its eruption from seeming inaudibility; when joined by the bass, the soundstage was panoramic.

I’ve saved the best for last. The Hsu 1220 is the only woofer in my experience that is able to repro-duce the sound of pipe organs for what they really are: great shuddering columns of air. The 1220, alone in the survey, is capable of flat response below 20 Hz, it is in fact flat to 19 Hz, and only slightly down at 16 Hz. The Saint-Saens “Organ” symphony actually had me fearing for the integrity of the picture window, it rattled so, while a small photograph was shaken off a nearby table. When most subwoofers get the room to vibrating like that, the sound tend to become what, for want of a better term, I’d call “sine-wavy”: a kind of undifferentiated low-frequency buzz that can be impressive but not terribly musical. But the 1220 lets you feel the sound as distinct frequencies, as deep, deep tones, half-heard, half-felt. And no matter the loudness, this “paper” tube never once announced itself: no squeaks, grunts, groans, or rattles, for all practical purposes inert.

The only thing I didn’t particularly care for was the string bass introduction to the Diana Krall album. The Hsu was as articulate as any of the designs, but there was a narrow range of notes that tend to boom, a range that corresponds to that 80 Hz peak in my room. As previously noted, this is the first harmonic of a standing wave clustered around 40 Hz and was a problem area for all the subwoofers in my room. It clearly does not originate from the Hsu itself but did seem to come through somewhat more strongly on the 1220 than on the others.

Which brings us to Hsu’s rather strong convictions about placement. He believes the best site for a subwoofer is right next to you, and he designed the 1220 for ideal placement on its side on the floor behind a sofa, which I tried with little satisfaction. But placing it upright next to the sofa resulted in startlingly improved articulation of the string bass in the Krall introduction. A measurement revealed that the 100 Hz trough was almost completely gone; the peak at 80 Hz was still pretty high, but because the relative levels of two modes were now effectively much closer to each other, there was much less of a sense of certain notes sticking out. The only penalty here was a severe drop in the bottom octave. Unfortunately, this placement is a complete non-starter here, as it puts the 1220 right out in the room (where, according to my wife’s best friend, “It looks like something that belongs in a disco”).

With a little more experimentation I found that moving the 1220 laterally about two feet from the corner where it was originally placed tamed that peak quite a bit and brought 100 Hz up somewhat without introducing serious ill effects (indeed, it even help bring up 40 Hz a little at the sweet spot).

I’ve never been a member of what someone (Irving Fried, I believe) once called the “sound-really-opens–up-if-you-move-it-a-quarter-of-an-inch-further-from-the-wall” set, but when you are dealing with bass nodes, small movement of a few inches really can produce large effects. Add to this all the other adjustments and the options become so numerous they start to drive you a little crazy. So let me leave the Hsu by pointing out that over most of its range it will not play quite as loud with as low distortion as the Velodyne, but it will play loud enough for almost any application short of plaster peeling. It’s a remarkable example of fresh thinking and applied technology in the service of music that no one in the market for a subwoofer should fail to audition.

TN1220HO
Clement Perry, Audiophile Voice, Vol. 4 No. 4

[Description of product ..] The 1220HO also came with it’s own 150-watt outboard amplifier/crossover that, in my opinion, is mandatory because it frees up having to use an existing amp to do any additional work…. [Note: the 1220HO currently has a 250W and a 500W amp option. No more 150W amp option]

I received a complimentary DTS sampler DVD while at the Stereophile Show last spring and decided to use this as a test for this evaluation. Going to the first chapter was a scene from Jurassic Park where the T-Rex escapes during a terrible thunderstorm. Well, the bass in this chapter is incredible, and what I heard with the TN1220HO was astonishing! My very first impression was how incredibly smooth or rather quiet everything sounded. For the first time, I was able to discern every little nuance of that scene without all the distortion I was used to.

The amount of air that I sensed being moved in my listening room was nothing short of amazing; this sound pressure level must be felt instead of being understood. There is something very special about the TN1220HO where it seems to spread its tremendous amount of bass energy across the room, enveloping the listener entirely with the cleanest and most coloration-less sound I’ve heard yet from a sub.

Next was Apolo 13, and need I say more? The sound of the take-off from Cape Canaveral was unlike anything I’ve heard in my room regarding low end detail, pitch and cleanliness. I am certain this is the result of the Hsu’s cylindrical enclosure. When it comes to absolute low end, this thing will shake up earthworms. Now, I don’t think the Hsu out-does the Carver Sunfire True Subwoofer (that simply shakes the house), but when it comes to making all those hairs on your leg stand up, not to mention the ones on the back of your neck, I doubt you can get more mid to low bass SPLs filling up a room like mine than with Hsu’s TN1220HO.

I felt as if I received some pretty tough shots after listening to the VR Virtual Reality in conjunction with the Hsu TN1220HO. I thoroughly enjoyed my time with this subwoofer, and it is sure to find its way into many people’s Ultimate Home Theater Setup. I consider it that good. It is different in design approach and the tube will not be for everyone; still I don’t know what it is.

I think that for the present, this beast is the most elusive creature there is in high-end, the one that the minute you obtain it, something else comes along to try to take its place. However, for now, the Hsu TN1220HO has made time stand still, and I continue to enjoy it immensely. (At least until some other wizard turns time back again.) [Editor’s note: Or rather, Clement, until the Hsu Marketing Manager comes around to take this subwoofer from you. Now, That will turn your time back on. – Gene Pits]

I therefore and hereby nominate this sub for what I have learned to appreciate more each “time stand still” day, getting Martin and Becky into the listening room to hear what T-Rex must have really sounded like.