Subwoofers

SVSound PC13-Ultra Subwoofer

ARTICLE INDEX
Introduction

SVS subwoofer One of my favorite nerd-words is "disintermediation." It's a polite economics term for "cutting out the middleman." A company manufactures products and sells them directly to the customer, cutting out the intermediaries in the supply chain and passing on the cost savings to consumers.

In the home theater world, the Internet allows smaller A/V manufacturers, who would otherwise never be able to afford large marketing and advertising budgets, to develop a following among its customers and grow beyond the geographic limitations imposed by brick-and-mortar companies. That's disintermediation.

SVSound (formerly SVS) is a prime example of this model. Based in Youngstown, Ohio, the eight-year old company has rapidly developed a reputation for making high-quality subwoofers at consumer-friendly prices. Its newest products, the PB13-Ultra, and the subject of this review, the cylindrical PC13-Ultra, incorporate a new 13" woofer and high-powered BASH amplifier. Given SV Sound's track record, I expected superb performance from the PC13-Ultra . . . and, I was not disappointed.

Specifications

  • Design: Ported
  • Driver: One 13.5"
  • Amplifier: 750 Watts RMS (BASH)
  • MFR: 18 Hz - 150 Hz ± 3 dB in 20 Hz Mode
  • 10 Hz, 15 Hz, or 20 Hz Tunable Modes
  • Dimensions: 46" H x 16" Diameter
  • Weight: 90 Pounds
  • MSRP: $1,399 USA Black Fabric Exterior

SVSound

The Design

Back in the day, SVSound's subwoofers looked nothing like the squat boxes that now dominate the market, but instead resembled large cylindrical-shaped towers. The reasons for this tubular design were based on solid engineering principles and practical considerations. Round speaker enclosures are generally stronger than a box of similar size, and lack corners that create uneven cabinet pressures and distortion. As a result, a cylinder shaped subwoofer will weigh less than a similarly sized box design. Plus, a cylindrical subwoofer will make a smaller footprint than a box subwoofer of equal volume, so it uses up less of your floor space. I suspect that the main reason companies went to the box-shaped design was the dreaded SAF (Spousal Acceptance Factor), and indeed, SVSound now makes box subwoofers to please the entire household.

amp panel While the basic design of cylinder subs haven't changed, the components have evolved over time. SVSound designs and builds its own speakers, in this case a 13.5" stitched foam-core/glass composite cone housed in a die-cast aluminum frame. The top of the cylinder sports three 3.5" flared ports, which when plugged, change the tuning and allowing deeper frequency response (more on that below).

The PC13-Ultra is powered by a flush-mounted BASH amplifier capable of 750 watts RMS. The back panel is packed with useful features and options typically found only in subwoofers costing several times the SVSound's $1,399 list price.

Connections include two inputs each (left and right) for both RCA and balanced XLR signals, plus matching outputs for easy daisy-chaining of multiple subs if you're so inclined. Phase control is adjustable from 0 to 180 degrees, and the defeatable internal crossover is adjustable from 40 – 120 Hz.

Advanced features include a room size compensation adjustment (set for small, medium, or large rooms), and a single band parametric EQ that can be set anywhere from 20-80 Hz, along with the level and adjustable Q (the spread of the EQ band).

top view Finally, there is a four-way subsonic filter, with settings at 20 Hz, 15 Hz, 10 Hz, or Sealed configurations. This setting is used in conjunction with the three ports housed under an easily removable grille at the top of the cylinder. When all three ports are open, the PC13-Ultra is tuned to 20 Hz. Plugging one port changes the tuning to 15 Hz, two ports results in a 10 Hz tuning, and plugging all three ports emulates a sealed configuration. As our bench testing showed, these settings were not merely window dressing, but had a noticeable effect on the PC13-Ultra's frequency response.




The Sound

I tuned the PC13-Ultra to 20 Hz mode for listening purposes, with all three ports open. Music, both CD and hi-rez, were played through the Oppo DV-980H via HDMI into an Integra DTR-7.8 THX Ultra2 receiver. Movies were played through a Toshiba HD-A2 HD DVD player into the Integra.

So as to not mince words, the PC13-Ultra knocked me on my tail. We're talking wall shaking, glass-rattling, floor-rumbling bass. The title track of the Eagles Hotel California (DVD-Audio) puts the kick drum way out front in the mix, and is EQ'ed with a fat low-end. The SV sub pushed so much air in reproducing the kick drum that it felt like I was sitting in front of a pile driver.

Nonetheless, the PC13-Ultra was very capable of being musical in its sound reproduction. Describing a subwoofer as being "fast" may drive some people batty, leading to technical discussions of damping factors, distortion at harmonic frequencies, and so on. But as a bass player who's played through many different amps and PA systems, I know that hitting staccato eighth-notes requires a system that will allow the listener to hear (and feel) each distinct note, rather than have them blend into a droning buzz. Paul McCartney's "Silly Love Songs" (from his All The Best CD - mock the song at your own risk) has a great walking bass line, and the SV let me enjoy each note being picked by Sir Paul.

But the real action was in movies. 300 (HD DVD) has a sprinkling of dialogue ("This is Sparta!"), but mostly consists of outrageous fight sequences, complete with charging rhinos and hordes of invaders so numerous that the ground shakes like an earthquake. The PC13-Ultra was up to the task, at times pressurizing the entire room with low frequency energy.

Shooter (HD DVD) has plenty of gunfire, and several fantastic explosions; especially at the end of the film when a mountain cabin filled with propane blows apart in a fireball. The PC13-Ultra made me feel like the cabin was really exploding in front of me; all that was missing was the heat blast.



On the Bench

All measurements (except where noted below) were conducted with the calibrated microphone placed one foot away from the bottom (speaker end) of the enclosure, with the microphone oriented parallel to the ground. For bench testing, the PC13-Ultra was moved from the front corner into the middle of the listening room, so it did not benefit from obvious room loading. The PC13-Ultra was tuned to the 20 Hz mode for sine wave tests. Room compensation and parametric EQ were both set to "off."


At 50 Hz, distortion was 0.4 percent.


At 40 Hz, distortion was still less than one-half of a percent.


At 31.5 Hz, distortion was barely over one percent, with each harmonic at diminishing levels.


At 25 Hz, distortion is up to 6.4 percent, still well within acceptable limits.


And at 20 Hz, distortion was 8.4 percent, still an excellent response. Note also how the third-order harmonic remains lower than the second-order harmonic, meaning that there is still additional headroom.

However, even those low frequency response graphs are somewhat unfair to the PC13-Ultra. Because 20 and 25 Hz signals approach the natural tuning of the cabinet, output at those frequencies was significantly higher through the top ports. For example, the below measurement at 25 Hz was taken with the microphone placed one foot away from the top port. I was able to get a 100 dB level measured from the top port with the input volume set 3-4 decibels lower. And look at that distortion reading!


And at 20 Hz shown below, measured from the top port, about 0.3%. This is really incredible performance!


So when I was measuring 100 decibels at 20-25 Hz from the bottom of the enclosure, the output from the top ports—what you would hear and feel in the room—was actually 103-104 dB!

The impact of various tunings is shown below, again measured one foot from the bottom of the enclosure, in a 10-100 Hz frequency sweep.


In the 20 Hz tuning, frequency response was essentially flat (with some accommodation made for room nodes) below a shallow roll-off starting at about 19 Hz, but still measuring a robust 85 dB all the way down to 10 Hz.


With one port plugged, and the PC13-Ultra set to 15 Hz tuning, frequency response in the mid-bass showed a slight hump, but the low end was basically flat all the way down to 14 Hz. Again, there is still significant power (83 dB) at 10 Hz.


With two ports plugged, and tuned to 10 Hz, the mid-bass remained slightly elevated with a dip between 18 and 30 Hz. But the 90 decibel signal didn't start rolling off until 13 Hz, and was only down 4 dB at 10 Hz, at which point the infrasonic energy started making me a little queasy (reminder to self, next time place the test bench a little further away from the device-under-test!)


In the sealed configuration (all three ports plugged), the trade-off is flatter response at higher frequencies versus a steeper roll of at the lower end of the spectrum. So there's a setting to please everyone.

Conclusions

The PC13-Ultra is a fantastic subwoofer. It has tons of power, useable output well into the infrasonic range, yet remains musical. How SVSound manages to make such an amazing product for $1,399 is beyond me. It must be that disintermediation thingy. I already own five subwoofers, but I still didn't want to let this one go. Highly recommended!