Source Technologies HVS 10 Subwoofer Review

Source Technologies HVS 10 Subwoofer​

Introduction
The subject of this review is the Source Technologies HVS 10 subwoofer. The HVS 10 utilizes a bandpass design, which is fairly unique in the home theater world. It measures 19.5"x14"X17" (HWD) and weighs 66 pounds, so it's a pretty substantial unit. The driver is contained entirely within the cabinet, so the 4" front firing port -- which Source calls an Aerovent -- is the sole way the HVS 10 delivers bass.

The amp is Class A/B and rated at 400 watts RMS, with no peak given. The quoted frequency response on the website is 30Hz-120Hz, while in the PDF file Source Technologies links to it's listed as 29Hz-100Hz. The latter also states the HVS 10 is capable of an astonishing 124 dB @ 2 meters. In spite of the discrepancy I found the stated lower response to be conservative; the HVS 10 was actually capable of more.

There is a 2 year warranty on the amp, and a very generous 7 years on the driver. Source Technologies has been in business since October of 1993. They produce a surprisingly broad variety of speakers and subwoofers, which means they should be able to satisfy virtually any need someone might have.

Source Technologies strikes me more like a "boutique" manufacturer than a classic Internet Direct company. Their website is a prime example; a dearth of photos (and the ones they do have aren't all that impressive), a fairly unglamorous appearance devoid of any flash, not a lot of product information, no way to order on line, etc. Were you to judge Source Technologies strictly by their website your impression would probably not be too favorable. I know mine wasn't initially, but as I found out these people much prefer to deal directly with you on an individual basis. Mass market "me too" products? Tons of advertising? Submit countless units for review? Not here; Source Technologies philosophy seems to be that they're perfectly fine to leave those practices to the companies who build things overseas. These folks actually want to hear your voice in order to ensure the product meets your exact needs.


Ordering
The review unit came in a black oak veneer and was priced at $1695. Source provides different finish options on most of their products, so if black oak is not to your liking I'm sure they can accommodate other finishes. That's one of the benefits of dealing with a company like this; don't like the standard finish? No problem, because they can probably change it to something that fits your situation better.


Unboxing
The HVS 10 came single boxed, but it was pretty thick; my guess would be around 500 pound burst strength. The unit was protected by styrofoam blocks that covered the entire top and bottom, both of which were broken though indicating it had a hard journey on the way to me (which reinforces one of the prime reasons why I hate styrofoam so much; softer foam would not have broken apart like this). The subwoofer itself was encased in a transparent plastic sheet, which was wrapped around it several times.

Included accessories were just a power cord and 4 small gold isolation cone-style feet. The documentation would probably be considered spartan in both volume and content if you happen to be unfamiliar with how to hookup a subwoofer because it consisted of only a two page Placement Guide and a single page Hookup Guide. One rather unique thing I did find in the box was a QC checklist, which was filled out by hand. Someone actually took the time to test this individual unit and then signed off on it. For those who may feel that's quaint, or even somewhat Norman Rockwell-esqe, I would beg to differ; in this day and age how many companies make certain ever product they sell is working before shipping it? Very few unfortunately. I found it refreshing to know the functionality of this particular HVS 10 was certified before it ever left Source Technologies.


Initial Impressions
The first thing that jumps out at most people is the bolted on top panel, which proved to be a bit polarizing (I had someone refer to it as "Frankensub"). Then there's the huge port on the front, which isn't typical either. Add to that the fact all of the HVS 10 is covered in black oak veneer -- except for the back and bottom panels -- and you end up with a subwoofer which looks like no other. That can be a good or bad thing though, depending upon your perspective. I'm not sure I ever became 100% comfortable with the appearance of the top panel, but the port never bothered me. Neither did the different finish on the back and bottom panel, which I consider of no real consequence; nobody ever sees that part of a subwoofer anyway, so who really cares how they're finished.

The massive 4" front port is flared on both ends, which cuts down on the potential for unpleasant noise, but it could definitely benefit from one addition; a screen on the inside portion. This thing is so large that I was able to stick my entire hand into the cabinet, which means all manner of other things -- from toys to small pets -- might find their way inside. Because there's no grill covering the front the lack of a screen may be an issue for some.

The cabinet is constructed from .75" MDF and feels very sturdy. The ubiquitous "knuckle rap test" results it a dull thud, which is exactly what you want to hear. The top panel is held in place by an amazing 24 custom screws, which are driven into threaded inserts. The top chamber is lined with a thin insulation -- possibly fiberglass based -- that's adhered to the side walls. The bottom chamber houses just the 4" port, and doesn't contain any insulation. The port tube extends from the front of the cabinet to within 2 inches of the rear.

Construction quality was first rate. The veneer was applied flawlessly, with no visible defects. I wasn't able to find a single screw that needed much in the way of tightening either. The overall appearance of the cabinet is proportional for the most part, with the exception that it's perhaps a bit on the tall side, but the dimensions don't really make it stand out.

The driver employed has a 10" aluminum cone with an oversized voice coil, thick rubber surround and a 90 ounce magnet. The basket appears to be powdercoated aluminum with a multitude of small round vent holes circling it's base. There is also a 1" wide vent in the center of the magnet, complete with a screen. The spider is made from an aramid fiber and has the leads woven directly in. Continuing the theme from the cabinets top -- where secure mounting is essential -- the driver is held in place by 2" machine screws driven into threaded inserts.

The amp Source Technologies uses is a Class A/B design -- meaning you should expect it to generate some heat -- but there are substantial fins to aid in dissipation. The internal electronics are housed in an isolated chamber, which I always like to see. This amp has the standard gain knob, a phase toggle (0 or 180 degrees), a power switch for off/auto, both high level and low level inputs and outputs, as well as selectable voltage (115 or 230 volts). But that's not all, there's also an adjustable low pass filter that can be set for anything from 50Hz-100Hz. You can completely disable it too, via a toggle switch. Another unique feature of the amp is there's also a selectable 12v trigger, so there are plenty of configuration options. Looking over the specifications for the amp I noticed there is a 4dB boost @ 25Hz and a 15Hz High Pass Filter.

As mentioned previously, the HVS 10 -- which stands for High Velocity Signature series -- uses a bandpass design. It's uncommon in the home theater world, with very few companies using this style of subwoofer. I had always associated them to bloated, sloppy, imprecise bass because most of my exposure to bandpass was those goofy little import cars and their dreadful "make my windows vibrate" sound systems. A lot of those people use bandpass subwoofers so I had begun to think of them in that light. Source Technologies has changed that for me.

According to Source Technologies the HVS system "plays louder with greater impact, typically 3-4dB overall increase in dynamic headroom". The main benefits are listed as:

1. Tuned air load, on both front and back of the woofer cone: Conventional subwoofers have only one tuned air system. The air load inside the box tunes only the backside of the woofer cone while the front of woofer fires randomly into the listening room. Our new HV/S system encloses the entire woofer, using 2 highly tuned air systems that are synchronized to one another, for significant improvements in distortion, resolution and power handling.
   
   
2. Lower Distortion: Less excursion means less distortion. The moderating influence of a tuned air load, on both sides of the woofer cone, limits excess movement, optimizes “travel area” and minimizes excursion. All forms of listening distortion are reduced by almost 50%.
   
   
3. Amplifier efficiency and dynamic range: For any given bass frequency, the excursion now required to produce it is reduced, resulting in less Back EMF (return energy sent back to the amplifier). This decreases reactive loading and the amount of amplifier “effort”, providing more useable power and cooler operation.
   
   
4. High acceleration, low mass, and port air as a medium to produce bass: Conventional subwoofers use an exposed driver, with high moving mass (200- 400 grams), to develop bass. Inertia, as a function of mass, restricts a woofer’s ability to change directions or “stop and start”. This has an adverse affect on transient response and the ability to follow the leading edge of the input signal. With an HV/S subwoofer system a mere 5-gram, vent air load creates a high velocity low frequency pressure wave. This air “piston” has extremely low inertia and therefore, high acceleration. Stop and start are instantaneous. Bass notes attack rather than lag.
   
   
5. Increased power handling with no compression: Power handling is determined by wattage, excursion, mechanical stresses and heat centered at the voice coil. High power or sound pressure creates added heat. Resistance to current flow across the voice coil increases as the voice coil gets hotter. Less current flow means diminished loudness, dynamics and impact. HV/S subwoofers employ cutting edge heat transfer technology. Our woofer motors use oversized voice coils with extra heavy wire and an aluminum former. The assembly is then fused to an aluminum cone. This acts as an enormous heat sink, providing cool operation at the highest sound pressure levels, for unrestricted power when needed.

Put succinctly, I was often stunned by how deep the HVS 10 could go. But it's not just the depth that I found so astonishing, it was the extraordinary clarity and precision with which it goes about it's business. The dynamics are very good, making both movies and music an absolute pleasure. Part of the reason may be attributed to the fact that, by design, a bandpass enclosure doesn't generally use an EQ or electronics to shape the response. Instead it uses the natural characteristics of the driver and enclosure together, in a purely mechanical fashion, so there's no artificial enhancements. That appears to make the output more 'pure', which in turn means better accuracy.


Setup
There's nothing special with regards to setup. For typical home theater usage you plug in an RCA cable from your receivers LFE/subwoofer out port, set the initial gain (volume basically) to 12 o'clock, flip the Low Pass toggle to Off and the Phase to 0 degrees, then set the power switch to "auto" -- unfortunately there is no Always On setting -- and away you go.

The markings on the amp are a little small, but the font is clear and legible. All the controls and switches feel solid and respond with precision. One thing I normally do is use a Y adapter so I can utilize both RCA inputs to increase the sensitivity a few dB. However, in this case I wasn't able to do that; while the amp does indeed have the feature whereby you can "multiple" the input sensitivity I found that made it a little difficult to adjust and get the tuning correct. Using a single input proved to have no liability though, so that's what I did for the duration of the review.


Listening
My living room is 13x17x8 (1768 CF), so it's not terribly large. The main seating position is approximately 11 feet from the subwoofer. All testing was done after the unit had been broken in for at least 25 hours, which is a bit longer then normal for me. I did this because Source intimated it would take a while for the HVS 10's driver to loosen up, so I nearly doubled my normal break-in time.

If anyone had told me that a single 10" driver was capable of doing what the Source Technologies HVS 10 could before I had a chance to review it myself I would have said they were nuts. It's simply not possible to get this level of clarity, volume and extension from such a modest setup. Unfortunately I would have ended up eating those words because the HVS 10 would have proven me wrong. It defies logic, that's for sure. No one will call this the prettiest subwoofer they ever saw, nor is it the least expensive, but for me it was unquestionably the most surprising. This thing rocks, plain and simple - there's really no other way for me to describe it.

The HVS 10 seemed to be composed and under control virtually all the time, with only a rare misstep, regardless of what you did or how loud you had it turned up. Watching TV? Please, that was no challenge. Movies? A few test scenes played at high volume caused a stumble or two, but 95% of the time it was pure bliss. Music? Absolutely delightful. I was digging deep into my CD collection to find gems I hadn't listened to in a long time. Truth be told, I may find it difficult to go back to any of my own subwoofers after this.

Nothing is perfect however... there were a couple of times that it seemed I felt bass more then hear it, as though there was a gap in the frequency response. While I've tested some fairly powerful subwoofers -- that also generated appreciable feel -- I don't recall encountering this type of behavior in the past. It never seemed as if the output was weak, just different somehow. The HVS 10 could also be pushed to the point were you got port chuffing. It took some pretty deep bass and/or elevated volume levels for it to occur, but when it did the sound was rather pronounced.


Movies/TV
I run each test scene twice; once while seated in my normal listening position, and then a second time while sitting a few feet from the subwoofer. This allows me to hear it as I normally would, yet also affords me the opportunity to determine if the subwoofer is straining even the slightest bit. Both tests are run at the same volume level, which is slightly above what I would normally use.

Lord of the Rings: Fellowship Of The Ring (Blu-ray)
During the opening scene -- One Ring To Rule Them All -- Saron's hand is cut off by Isildur, and the Ring hits the ground with a very deep bass wave. The low frequency sweep is even more pronounced when Isildur picks the ring back up. The HVS 10 was able to produce a ripple of bass in my chair for both effects, and that was at -15dB.

During the Bridge Of Khazad Doom there is a foreboding rumble that dominates the background effect at times. The HVS 10 produced this in a very convincing manner. The depth and impact of the crumbling walls and staircase was nothing short of amazing. My favorite part of this scene is the Balrog's roar. There's an instance when you see it for the first time that I just love to crank way up. He jumps out of a cavern and lands right behind the Fellowship with a thud, and then lets out a fire-breathing roar. I really enjoy seeing how loud it will play. With the HVS 10 the Balrog's roar and pounding footsteps had great depth, even at -5dB.

Avatar (Blu-ray)
During the Assault On Home Tree there are low frequencies, ultra low frequencies, explosions, artillery fire, gunships, you name it. Certainly enough things going on to provide a really good subwoofer test. Most of this movie was played at -15dB.

As the gunships approach Home Tree you can almost feel the underlying intensity. The roar of their engines, the sound of the rockets being launched, the impact of each explosion, the crackling of the massive roots as the tree begins to list, and all the way to the point where it's toppled and crashes into the ground the low frequency was surging through my chair. In particular, the rockets and incendiary missles hit with a nice impact and solid percussion. You could almost feel the destructive force as Home Tree starts to fall. When it finally hits the ground my floor shook a little bit.

When the gunships are leaving their base camp during the Battle For Pandora the engine roar was almost palpable, as was the wing flaps of Taruk Mato as he flew towards the encroaching army. When the gunships land on Pandora you could feel the roar of their engines. The stampede effect from the warrior clans as they descend upon the invading armies was very potent. The explosions and gunfire during the actual battle were rendered in a forceful, clean manner.

War of the Worlds (Blu-ray)
The archetype. Perhaps the most recognized subwoofer test movie of all time. The depth and volume of bass that occurs during a few scenes is simply amazing. If you want to see what your sub is capable of this movie can certainly be used as a barometer. With subterranean vibrations, exploding pavement and collapsing buildings you have ultra low, low and mid-bass frequencies pouring out of your subwoofer. One of the most punishing combinations there is, and an excellent way to really push something to the brink. So what did I do? Run it at -10dB, just to see what the HVS had.

The HVS 10 produced one of the the clearest renditions of The Machine Emerges scene I have ever heard. The depth and quality of the various earth-shattering effects was beyond anything a little 10" driver should have been capable of. Equally impressive was the Heat Ray, which had a wonderful punch and clarity as it went about annihilating everyone. The destruction of the bridge behind Ray's house during The Escape was awesome, with excellent definition. That part of the movie is actually the loudest passage there is, yet the HVS 10 shrugged it off. During all this mayhem I heard no untoward sounds from the port.

The plane crash in At The Window put a smile on my face. I replayed this scene at 0dB, and while I had a hard time handling the volume the HVS 10 didn't seem to. Hudson Ferry has some extremely low content, especially when the alien tripod bellows. As usual the HVS 10 was clean and precise; you felt the bass as much as heard it. Next to The Machine Emerges, The Battle Begins is the scene that probably has the most low-level content. The tank fire and missiles had a percussive effect. Even the bombs going off in the background were intense, with a very solid thud.

It was at this very moment that I realized just how much I liked the HVS 10. As I reached over to take a drink from my water cup I noticed ripples emanating from the center, ala Jurassic Park. I stared at that in disbelief for a few seconds, thinking "are you kidding me?".

Tron: Legacy (Blu-ray)
The soundtrack from this movie can drone if you don't have the right subwoofer. Thankfully the HVS 10 proved to be the right subwoofer.

The propulsion engines of the Transporters in The Grid were potent, almost too much so; they started to get a little annoying quite frankly (research has indicated that might be the soundtrack though). The elevator that takes Kevin Flynn down to the lower level sent ripples of bass through my chair as it descended deeper and deeper.

The Daft Punk soundtrack at the beginning of The Games caused my closet door to vibrate. That would be my hallway closet. During the Disc Wars sequence there are various parts where the bass is so deep that you can (hopefully) feel it coursing through your chair, and I did. The fireworks they launch hit with a nice solid explosion, and the Light Cycle battle was intense. I don't think I've ever heard this movie's audio track rendered with such detail. Deeper, yes, but not with this level of definition. That's saying something too, because this is a pretty lousy audio track.

Underworld: Awakening (Blu-ray)
This movie unsettled the HVS 10, one of the few times it lost composure. Even at -20dB certain portions of a few scenes caused audible port noise at my listening position, which was about a dozen feet away. A more effective limiter might have helped mitigate this.

All of the gunfire -- and most of the explosions -- came across with the accuracy I had grown accustom to, producing sharp impacts and realistic sounds. However, the footsteps from the huge Lycan that Selene battles in the underground lair caused the HVS to struggle; it simply was not able to produce sufficient depth, yet it tried anyway. Unfortunately the resulting sound clearly indicated that the HVS 10 was being pushed beyond it's abilities.

Cloverfield (Blu-ray)
Unlike the previous movies, where I only used a few scenes to test, I watched all of Cloverfield. To be honest, this is not my favorite movie -- the camera work is terribly distracting -- but the special effects and soundtrack are impressive.

The opening of the movie, where it's just the invading beasts footsteps, caused a touch of port noise that I could hear at my primary listening spot. It wasn't as bad as what I experienced during Underworld: Awakening, but there was definitely some noise that shouldn't have been there.

The music playing at the party towards the beginning of the movie had the same type of effect it would have if it were live, which was quite enjoyable. The first few explosions, where it culminates in the Statue Of Liberty's head being tossed onto the street, where really potent. The destruction of the Brooklyn bridge was intense and forceful, with great texture.


After all the movie tests had concluded I checked the amp and found it was quite hot, as in "don't touch me". Class A/B amps are notorious for that, but I can't say I would be comfortable if it ran this hot all the time. Thankfully that wasn't the case; during normal usage the amp would get warm, but nothing like it did after pounding away for several hours with test scenes.


Music
Under normal circumstances I don't listen to a lot of music when reviewing a subwoofer -- it's mostly TV and movies -- but in this case I made an exception because I was really enjoying what I heard. I would consider the HVS 10 to be a musical subwoofer.

Joe Satriani - Flying In A Blue Dream (CD)
The bass in this song is rather thick, almost like a synthesizer. The riff itself is very simple, so it doesn't seem like an ideal song to test with, but in order to play it properly a sub needs to be articulate, otherwise it just comes across as sloppy and indistinct. The HVS 10 had no such problem; the bass guitar came through with authority and definition.

Joe Bonamassa - Black Rock (CD)
If you like straight ahead, no frills blues music you have to pick up a Joe Bonamassa CD. Better yet, go see him live - you won't regret it. I certainly didn't. He also plays in the band Black Country Communion, which consists of Joe, Glenn Hughes (from Deep Purple) and Jason Bonham (the son of... well, you know that last name). To say Joe knows how to play a guitar would be an understatement.

Black Rock is an awesome CD, definitely one of my favorites from his catalog. The slightly Celtic sounding Quarryman's Lament has a deep fuzzed bass that thundered out of the HVS 10. The drums are recorded pretty far back so there isn't a lot for a subwoofer to do with those on this tune; it's mostly bass and Joe's voice that dominate here. I could actually feel the bass during parts of this song, that's how deep it goes. Bird On A Wire starts out with this haunting wind instrument, with an almost middle eastern sound to it. What follows is a bit of mandolin (no kidding) but in short order it turns into a typical heavy blues song, with an extraordinarily deep bass guitar. The kick drum is back in force too. There were waves of sound careening towards me at -10dB, yet the depth and clarity never suffered. I must have played this song at least 3 times.

Heart - Various (CD)
Heart tends to have fairly simply arrangements punctuated by good rhythm and a lot of powerful vocals, courtesy of Ann Wilson. Heartless is a good example of that, from the Magazine album, so I cued it up first. True be told, this is really about the only song I liked from Magazine. Both Steve Fossens bass guitar and Michael DeRosiers drums came through with exceptional clarity. The HVS 10 didn't even break a sweat on this song. From the album Dog And Butterfly I chose Straight On, which opens with a tandem of the bass and drums. What better way to test a subwoofer then low end with nothing else going on? At -10dB the bass guitar was clear and powerful, but I would have liked a bit more punch from the kick drum. It was crystal clear though, and the whole song was a pleasure to listened to. The last track was Crazy On You from Dreamboat Annie. Steve Fossen was still manning the bass, but Kat Hendrikse played the drums on this one. It was still what I was looking for though, because the rhythm section plays a prominent role. The HVS 10 willingly obliged with dynamics and precision, regardless of the volume.

Motley Crue - Kick Start My Heart (CD)
Seems like almost every system I review there's some Motley thrown in there, and almost invariably that includes Kick Start My Heart. Why? Because it's a song that you simply can't keep turned down low; you really have no choice, it has to be cranked, and that's precisely what I did. Nikki Sixx bass is always recorded too low for me -- so I couldn't judge the HVS 10 on that part -- but Tommy Lee's bombastic kick drum hit with alacrity, pounding away at (what's left of) my ear drums. The HVS 10 loved this song, and so did I. Turn it up!

Pink Floyd - Dark Side Of The Moon (CD)
How do you pick just a few tracks off this CD to test with? You don't -- that would be sacrilege -- so I cued up track one, set it at -10dB, and sat back for what I hoped would be an exhilarating experience. I wasn't disappointed. The opening heart beats on Speak To Me/Breath sounded like I was inside an EKG machine. Roger Waters open 'E' bass note at the beginning of Time flooded my room to the point of almost creating a pressure wave. The combination of kick drum doing the heart beat, bass guitar and synth was practically intoxicating. The opening bass riff from Money was a pure delight, with amazing clarity and depth. I could actually hear Waters pick hitting the strings almost as though he was sitting 10 feet from me. There was even some vibration from the bass guitar being transmitted to my recliner, which goes to show you just how much depth this subwoofer has; a 10" driver is simply not supposed to do something like that. Us And Them just poured deep, enveloping bass into every corner of my room. Without question this was the track that sounded the best to me.

Electronic (CD, MP3, WAV)
The Bass Mekanik CD is recorded on the hot side, so most of it was run at -20dB. Even with that Welcome Stranger was creating a mini pressure wave in my head. That wasn't even the impressive part, it was the articulation; the HVS 10 was producing all the punishing bass with amazing clarity. The frequency sweeps were handled with authority; it couldn't quite produce the really deep notes, but it did far better then it had any right to. This was the first subwoofer I've tested that didn't turn the eponymous Bass Mekanik song into a blur of painful and indecipherable noise, although that's what this song is for the most part. The HVS 10 struggled with the very lowest notes here as well, but just like Welcome Stranger I was left in awe of how well it was doing. On Funky Annihilating Bass my notes simply read "how on earth is this thing able to do that?".

When testing a subwoofer you simply must cue up Bass-o-Tronics Bass I Love You. It's almost mandatory. This turned out to be another song where the last few Hz were not played, but the HVS 10 did a solid job nonetheless. Sub Bass Excursion lost a little clarity though, but that was supplanted with pretty significant waves of bass sent through my chair. Unfortunately it was also accompanied by considerable port noise, which was evident at my primary listening position. However, the bass wave coursing through my chair was just unbelievable; the HVS 10 may have been struggling to keep up but it just kept trying anyway.

There's a guy here on HTS who goes by the name Dub King that makes bass heavy electronic music available free of charge, so I downloaded a few of his songs to try out. Turns out a couple of them are absolutely savage. On Dub Kingdom Come there are a few parts where I could feel it pulsating in my chest. Halloweener has some brutally low bass, so intense that it caused the port to make noise again. This one may become one of my new test tracks - it's merciless! Dead Serious was essentially a massage with waves and waves of bass, some of which were transmitted into my chair. If you want to see what your subwoofer is capable of try some of Dub Kings music. You won't be disappointed.


Conclusion
Take a single 10" driver, match it with an amp that has average power and then place both in a fairly standard sized cabinet and what do you get? Nothing special, right? Wrong! At least in the case of the Source Technologies HVS 10 that would be wrong; what you ultimately end up with is something very special. There is nothing about it's appearance or configuration that suggest it should have this level of clarity, output and extension, yet somehow it delivers on all three. I was left in awe by what I heard most of the time. At this point I'm rarely surprised by anything I review, but the Source Technologies HVS 10 certainly caught me off guard.


Please use the Source Technologies HVS 10 Discussion Thread for questions and comments




These measurements were taken using XTZ Room Analyzer II Pro. The unit was indoors, physically positioned in the center of my listening room with the microphone tip placed at the opening of the port. No other speakers were running.