Product Review -
HSU Research HRSW12Va Subwoofer - May, 1997
By Stacey Spears
Hsu Research HRSW12Va Subwoofer; Downward firing 12" driver in ported cylindrical enclosure; size 22.5" H (including 2.5" spiked feet) x 23" diameter; black cloth cover on sides; Zolatone (granite) paint finish on top (light oak and dark walnut available for $75 extra); weight 50 pounds; separate 250 watt amplifier included; connections for left and right inputs from preamplifier (RCA) and speakers; 91 Hz active low and high pass filter - fourth order; other crossover frequency modules available at $15 each (28 - 155 Hz); $1,000, Hsu Research, 14946 Shoemaker Avenue, Unit L, Santa Fe Springs, California 90670; Phone (562) 404-3848.
The subwoofer is, without a doubt, one of the
coolest pieces in a home theater or hi-fi system. Whenever home
theater equipment is being demonstrated, there is usually a film
that is full of explosions, or a selection of music like the 1812
Overture in the case of a high fidelity audio system. There is no
better way to awe anyone than with a seismic event. But you and I
both know that quantity of sound is not everything. Obviously,
quality takes front seat to quantity any day. Most chain stores
do not understand this concept and usually give a very poor
presentation, often, with distorted bass. The store environment
does not sound like your family room anyway, so what you hear in
the store is most likely not what you will hear when you get the
equipment home.
Enter Hsu Research. Hsu sells factory direct with no middle
person to raise the cost or give a poor presentation of their
product . The only problem with factory direct is that unless you
live in the area, you will only be able to audition the Sub in
your house. THAT'S THE POINT!
Two years ago, John Johnson gave praise to the HRSW12V in
Secrets. After several refinements, Dr. Poh Ser Hsu has unleashed
upon us a new updated version. Is it as good as its predecessor
or better? Let's take a look.
In the Beginning
Originally, Hsu had the amplifier built into the bottom of the
12V. It was later removed and put into an external case that
matched the top of the subwoofer. The amplifier was removed to
cut down on the heat created from being in an enclosed
environment and also to minimize any effects that the vibration
from the subwoofer might cause. With the 12Va, the amplifier is
now in a 19" wide full size case. It is much more attractive
than the little cube that it resided in before. It is also a
beefier amplifier now producing 250 watts of power (into 4 ohms);
the previous amp was rated at 150 watts.
Also inside the amplifier case there is a crossover, phase, and
soft clipping protection circuitry. On the front of the amp you
have the power switch and level control. On the back there are
line level and speaker level inputs, outputs, as well as the
phase, crossover on/off, and soft clipping switches. The phase is
selectable between 00 and 1800. The crossover is a plug-in module with the factory
setting of 91 Hz. If your surround processor has a built-in
crossover, you can bypass the Hsu crossover. Other modules are
available; they come in sets of three, one for the low-pass and
one each for the hi-pass channels. Soft clipping is a protection
system; it should be used when you have those friends over who
like to turn up the volume when you are not looking. This feature
rounds off the square waves when the amp starts to clip.
While the 12Va is identical to the 12V on the outside, when you
take a peek underneath, you will notice the first difference,
namely the presence of two ports. The 12V had one 3.75"
diameter port flared at only one end, while the new 12Va has two
4" diameter ports that are approximately 42" long,
flared at both ends. The 12V was able to reproduce 20 Hz, but the
12Va at 20 Hz is MUCH, cleaner. The 12" driver has also been
improved; it now contains two magnets instead of one and has
about double the excursion. (This baby moves!)
The Hsu may very well have "Spouse Acceptance Factor".
The other day my parents were over, and my step father asked me
why I was fiddling with the end table When I informed him it was
a subwoofer he was very surprised. I could see the look in his
eyes; he can now sneak some extra subs into their house and tell
my mom that it is new furniture. Yes, my parents are hip, they
have a little LD collection going, along with DSS, a 50"
16:9 TV, and the full home THX setup.
There are three tops available for the 12Va. The standard is
Zolatone [click here for photo],
while an oak top [click
here for
photo], and a walnut top [click here for photo]
are optional.
Taking a First Look
When I first plugged in the sub, I positioned it as a coffee
table; this is the recommended setup from Hsu (however, the amp
is not compatible with caffeine). The first thing I noticed was
that the sub started to rock back and forth, kind of like R2D2
from Star Wars, when I put on ID4. I put a little weight on the
top, and that held it in place. The reason it is so light is
because it is made out of paper (the body is a cardboard
cylinder), not wood like traditional speakers. A cylinder is very
rigid and eliminates standing waves because none of the sides are
parallel. (The top and bottom are parallel.)
Like all loudspeakers, the placement of the sub is very
important. I have experienced the worst case scenario from
absolutely no bass to extremely boomy bass just by placing it
wrong. While I lived in my last house, I brought home a sub one
day and put it where I had room, i.e., the entrance by the front
door. When I hit "play", there was NO bass from my
listening position; instead all of the energy was by my front
door. What I ended up doing was placing my sub at my listening
position, putting on pink noise, and running around the room
looking for the best response from the speaker. When I found the
spot, this is where I placed the sub. Voila, I had good bass at
the listening position!
Hsu goes to great lengths to help you place the sub in the
correct position. When I obtained the 12Va, Dr. Hsu had me draw a
diagram of my room, and he then proceeded to recommend a couple
of starting places. As I said before, I started by placing the
sub in front of my couch as a coffee table. This is their
recommended position, as it is supposed to help with the time
alignment of the sub with the main speakers. I then moved the sub
to the front left corner of my listening room, and the bass was
improved, although a little boomy. My surround processor allows
the delay of any channel; this gave me a little more flexibility
in the subwoofer placement. I finally settled with the sub along
the left wall, a few feet out from the corner; this is where I
felt the bass was the cleanest.
The Bottom Line (or notes)
I have three letters: D.T.S.!!! If you want to take advantage of
DTS, you will need a sub that can handle it. The Hsu had no
problems with the incredible bass of anything I threw at it. For
those who have experienced "Jurassic Park" on your Pro
Logic system, you will be blown away when T- Rex stomps in DTS. I
was afraid that while playing the disc that either (A), my house
would collapse, or (B), a Cal Tech scientist would come knocking
on my door saying something about the epicenter. With
"Apollo 13", I thought the 12Va was going into orbit
along with the Apollo 13 capsule! Not once did the 12Va have any
problems reproducing the low frequency information. On the THX
WOW disc, there is a rattle test that plays from 20 Hz to 200 Hz,
and is used to find all the rattles in your listening area. Not
only did the Hsu find every rattle in my house, but in the
neighbors' homes as well.
For me, how the sub worked with music was the real key, because
any sub can boom-boom with movies. The first thing I listened to
was the CD included with the sub: "Virgil Fox"
(LaserLight 15 313). WOW!. This CD dips below 20 Hz, and the Hsu
goes with it. I then proceeded to listen to "Pomp &
Pipes" (Reference Recordings RR-58CD). This CD has been
known to damage some speakers, but the Hsu performed flawlessly.
Then there was "The Great Fantasy Adventure Album"
(Telarc CD-80342), which is another sub killer, and the Hsu
prowess continued to be evident. With DTS CDs, such as Marvin
Gaye's "Forever Yours" (DTS CD 1002), the bass was
awesome. "I heard it through the grapevine" was
incredible! The last song brought with it some visions of dancing
raisins in my head (remember the TV commercial?)
While testing the 12Va, I had it configured in many different
ways. For most of the time with the 5.1 soundtracks, I had it set
up as a dedicated LFE channel. I used the crossover built into
the processor, which was set at 120 Hz. When I would listen to
music and standard Dolby Surround material, I reconfigured the
sub as a "mono" sub like in the traditional THX sense.
I would send all 80 Hz and below info from all channels to the
sub. Again, I used the crossover in the surround processor with
it like this, and the crossover frequency was 80 Hz.
I didn't bother with the usual frequency response chart, because
the sub was obviously producing tremendous bass, and I was more
than satisfied. However, I will give you one value that I measure
in my listening room from my usual spot, and that was a whopping 108 dB at 20 Hz!!! I also took the sub to work and put it in the
middle of our parking lot, which is about 20 feet from the
building (early in the morning before anyone arrived - the
outdoor idea came from Dr Hsu himself), and at 1 meter, I
measured 100 dB at 20
Hz. So you can see that there was some
boost because of my room.
Associated Equipment
Along with the Hsu, a Pioneer (CLD-97 with
Faroudja Comb Filter) played the LDs. Toshiba (SD-3006) supplied
the DVD experience. Audio Alchemy spun the CDs. Meridian (565 w/
7.1) provided the surround sound experience. Amplification for
the other 5 channels was courtesy of Sunfire (Cinema Grand), and
the loudspeakers were Mirage and B&W. Equalization was
provided by Audio Control with the Bijou THX 7 channel EQ. The
video display was a Pioneer (PRO-77) and a Toshiba (TW40F80).
Various laserdiscs were used in DTS, Dolby Digital, and Dolby
Surround as well as several music CDs, in DTS and standard
stereo.
Conclusion
Subs have always been great additions to home theaters, because a
movie soundtrack is usually full of LOUD, DEEP effects. Subs have
not always been welcome in a high-end audio system because,
quality of the bass becomes an issue, NOT just quantity . Well,
Bo may know a lot of things, but Hsu knows subs, and Dr. Hsu has
fine-tuned the 12Va. It blends as well with music as it does with
movies. At $1,000 this is one of the best deals on the market.
If you are looking for even more bass, a second 12Va would
further improve things. Stereo subs add quite a bit to the sound
stage, and in today's market, $2,000 for this much low frequency
power is not terribly expensive. If you already own a six channel
amp, you can purchase the subwoofer unpowered for $550. Be sure
that the amp can provide 250W rms into 4 Ohms.
Stacey Spears
© Copyright 1995, 1996, 1997
Secrets of Home Theater & High Fidelity
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