SVS SB16-Ultra Sealed Subwoofer Review

After the positive impression that SVS’s PB16-Ultra left with us in our review late last year, it wasn’t long afterward when we inquired about the possibility of reviewing its sealed counterpart, the SB16-Ultra. The PB16-Ultra had set the bar very high for our expectations, and we wanted to see what SVS could do in a sealed subwoofer using much of the same technology employed in the PB16-Ultra. However, we also knew that the SB16-Ultra wasn’t simply a PB16-Ultra with a smaller, sealed enclosure. In our review of the PB16-Ultra, we stressed in the measurement analysis section that since there are some significant design differences in the driver from the SB16-Ultra, it would be misguided to judge the SB16’s performance from the PB16’s measurements. We were curious to see how the SB16-Ultra would compare to the sealed mode performance of the PB16-Ultra and also how it would stand on its own apart from comparisons to its larger brother. In this review, we will see what SVS brings to the market of sealed subwoofers for its $2k price point.

Unpacking and Setup

    

Packing for the SB16-Ultra was similar to the PB16-Ultra, so, in other words, it was very good and well thought-out. The SB16-Ultra arrived on a pallet. It was double boxed and sandwiched between three large foam pieces on the top and bottom. Additional foam pieces protected the side edges. Unpacking instructions are clearly labeled on the box itself, and it makes unpacking the SB16-Ultra a breeze, even though it weighs a hefty 122 lbs. While it takes two people to safely carry the SB16, there are built-in handles in the box that makes that a cinch. Once you have the box in room, you can slide it into place on the lower cardboard packing pieces, and that is easily accomplished by one person. After you have slid it into it final destination, you can conveniently slide the low pieces out from under the subwoofer, and it plops down into place. The SB16 is double-bagged, with a soft cotton bag protecting it from scuffs underneath a thick plastic bag protecting it from moisture. After unbagging, it, you may want to handle the SB16-Ultra with cotton gloves to keep its gloss finish unmarred by fingerprints. Overall, the SB16 is very well-protected from rough shipping, and, despite the SB16’s heavy weight, SVS has made it easy to unpack and place. This is top-notch packing work. I recommend holding on to the packaging in the event that it has to be shipped or relocated to another home, since acquiring packaging of similar quality for this 122 lbs beast will not be easy. 

Appearance

With its pristine gloss black finish, rounded edges, angled front display, and lustrous fiberglass resin composite cone, the SB16-Ultra is one pretty subwoofer. Its 20” cube dimensions add symmetry to the mix as well. This has to be the nicest looking subwoofer I have dealt with to date. However, if the grille is used, it messes up a lot of that. The grille is a very heavy-duty steel unit, and, unlike many other subwoofer grilles, it really will protect the driver, but in doing so it greatly diminishes the aesthetic elegance of the SB16. I think that most owners of the SB16-Ultra will use it sans grille when they are able to do so. This is a gorgeous sub that ranks very high in spouse-approval-factor, although it is slightly large by many people’s standards. That black gloss is mirror-like in its fineness: witness the reflection of the ‘Finding Dory’ blu-ray case above. The finish is certainly a major contributor to the overall cost, but once you get that thing in your home, it will be difficult not to think that it is worth it.

Design Overview

    

SB16-Ultra Amplifier (left) and Backpanel (right)

Since the SB16-Ultra does share many of the same attributes as the PB16-Ultra, I will point you to that page in our PB16-Ultra review, and spend our time in this design overview discussing the differences. The amplifier is the same 1,500-watt class-D Sledge amp, with the same interface, remote control, and smartphone app. The chief difference from the PB16-Ultra is the sealed design of the SB16-Ultra. Ported designs like the PB16-Ultra have a lot more deep bass headroom, but the enclosure size must necessarily be much larger. Port generated output is very efficient but requires more cabinet space to work well, and the major contribution of port generated output tends happens over a narrow band in low frequencies. Those willing to give up some low-frequency output can still get very good performance from a sealed enclosure over most of the subwoofer frequency band but from a much smaller enclosure.

SB 16-Ultra Driver

The differences between the PB16-Ultra and SB16-Ultra do not end there. The drivers used in both subs are similar in design in some aspects; for example using an 8” voice coil, 16” woofer, massive 56 lbs magnet, and so on, but there is some key differences, one of which is that the SB16-Ultra uses an overhung driver instead of the underhung configuration of the PB16-Ultra. In underhung drivers, the height of the coil winding is not larger than the magnetic gap that the coil travels in. This means that the coil’s travel within the magnetic gap is always going to be subject to the same amount of magnetic force as long as it stays within that gap. Because of this, the coil’s travel within the gap is very linear and well-controlled. The disadvantage of this approach is that since the gap is larger than the coil’s height, a lot of the force from the permanent magnet is wasted, because the coil only occupies a part of the gap and is therefore only using a part of the magnet’s available force. An overhung design, by comparison, always has some coil in the permanent magnet’s field, so none of the magnetic field is wasted. Overhung drivers do see waste too, since only part of the coil is ever in the gap, but in the case of SVS’s driver with its monster 56 lbs magnet, the force of the permanent magnet is enormous. Taking full advantage of that powerful magnetic force can give the driver more motor force and greater sensitivity, both of which can come in very handy in a small, sealed enclosure that will have more internal pressure. This is why SVS opted for an overhung design for the SB16-Ultra; it makes more sense for a small, sealed cabinet. 

There are other differences between the SB16-Ultra driver and PB16-Ultra as well. Many of the parameters of the SB16-Ultra driver have been optimized for its smaller, sealed enclosure, for example, the suspension used is not like the PB16-Ultra and wouldn’t work as well. The SB16-Ultra driver is specified by SVS to have a 65 mm xmax, meaning that this driver should have a bit over 2.5” of linear excursion on tap. In comparison, most drivers around this diameter would be lucky to have 2.5” of available throw at all, let alone 2.5” of linear throw.

The design philosophy of the SB16-Ultra seems to be SVS’s answer to the question of how much power, mass, and technology can fit in a 20” cube. As with the PB16-Ultra, the cabinet is solid like a rock, to use the cliche. In fact, in its weight-to-size ratio it very much feels like a small boulder. Of the 122 lbs of the SB16-Ultra, the driver weighs 64 lbs, which means the amp and cabinet somehow weigh a hefty 58 lbs, an extraordinarily large amount for such a small sub. The cabinet paneling is 1” thick MDF all around, except for the front baffle which is 2” thick. There is a 1” thick window brace in the center of the cabinet which supports the motor of the driver. Dacron is used as cabinet stuffing. Unless you are a professional weight-lifter, two people are needed to carry it despite its modest size. SVS uses some wide, spiked feet that have a rubber-covered tip so it does not scratch the floor. However, if you drag or push the sub, it can leave dark marks on the floor surface, so if you want to slide the SB16 in place, the use of furniture sliders is advised. The pointed rubber feet will sink into the carpet or rug so the SB16 bottom surface will likely be resting on the fabric surface. If you want the sub to be elevated off of the fabric of a rug or carpeting, the use of SVS’s SoundPath Subwoofer Isolation Feet would be a perfect fit.  

SVS SB16-Ultra Sealed Subwoofer Listening Tests

The location that worked best for the SB16-Ultra turned out to be right behind my sofa, and this placement gave up output below 30 Hz for a relatively smooth response above that point. This location played up the strengths of a sealed design like the SB16-Ultra instead of shoring up its weaknesses, i.e. deep bass. Receiver used was a Pioneer Elite SC-55 with a variety of different speakers, and the crossover was used mostly at 80 Hz and also 100 Hz. Since room acoustics have a huge effect on low frequencies, the way this sub sounds in my room at my listening position is not necessarily going to be the way it sounds anywhere else for anyone else, so readers would do well to keep that in mind, and not just for this subwoofer in this review, but for any subwoofer in any review.

Music Listening 

Contrary to popular belief, many albums featuring bass guitar playing aren’t great for demonstrating subwoofer performance, because much of the actual bass guitar playing lay above subwoofer frequency bands. The subwoofer may get to reproduce the fundamentals of a few notes here and there, but, for the most part, it isn’t given much to do. One exception to this is Stanley Clarke’s ‘1, 2, to the Bass’ which keeps the sub busy for most of this album’s running time. Stanley Clarke is, of course, one of the great bassists, and ‘1, 2, to the Bass’ is an album where he brings in a variety of different styles and performers for a range of different musical styles, from R&B, electro, funk, and hip-hop, and even a track of Indian music. The SB16-Ultra had no trouble keeping up with Stanley’s bass guitar, with its sharp attacks and sudden stops. The SB16-Ultra also kept kick drums tight and natural sounding, at least for those tracks that used real drumsets. Other tracks used drum machines, and the thump of the electronic kick drums was not lacking on the SB16-Ultra. The SB16-Ultra kept the instruments separate, and there was never any confusion between any low-frequency instrumentation, nor was there confusion in pitch, as the SB16-Ultra clearly rendered the notation of Stanley’s performance, no matter how rapidly he was playing.

One album I thought would make for a good test of subwoofer sound is Steve Roach’s 2008 double-disc opus ‘Arc of Passion’. ‘Arc of Passion’ is comprised of three long-form electronic music pieces, with the middle song lasting an hour, and the two others lasting about 20 minutes each. The two 20 minute songs are atmospheric soundscapes created from sweeping synth pads, bells, and drones, and the hour-long centerpiece is made from many layers of arpeggiated synths using pulsating, pounding electronic sounds reminiscent of some of Tangerine Dream’s mid 70’s output. In the hour-long piece, the sound becomes a bubbling cauldron of various bass sounds that induces a sense of propulsion and drive. The SB16-Ultra executed the drones in the light airy passages with enough subtlety that I didn’t know where the main speakers ended and the sub began; it was one sound, and a delicate balancing act to pull off. In the hour-long piece, the sub’s activity was more evident but only from the use of deep bass in the recording, and the bass in the recording was still seamlessly combined with the higher-frequency content. Soft drone sounds were kept separate from the bass line itself, which was kept apart from the effects noises that frequently dipped into subwoofer range frequencies. The SB16-Ultra had no trouble with the complex use of bass in ‘Arc of Passion’ and helped to make it a pleasure to revisit this mesmeric album.

For bass heavy music of a more traditional style, I turned to the mighty pipe organ in organist Felix Hell’s recording “Organ Sensation”. Felix Hell sounds like the name of a punk rocker, but it is a more natural name in Germany when this performer was born. Felix is a musical child prodigy and has been performing organ concerts around the world since before he was eleven years old. ‘Organ Sensation’ was recorded at the First-Plymouth Congregational Church on their massive Schoenstein organ and features many compositions by Franz Lizst, a few by Alexandre Guilmant, and a handful of songs of other composers. ‘Organ Sensation’ is on the bombastic side of organ recordings, using notationally dramatic compositions, which is perfect for demonstrating the virtuoso Hell’s extraordinary talent. It does have moments of calm as well, but those looking for a relatively animated organ recording would do well to seek out ‘Organ Sensation.’ The SVS SB16-Ultra was capable of subtlety but also brought grandeur when asked to by the 32-foot pipes of the Schoenstein organ. These pipes are able to produce 16 Hz notes with force. While my chosen subwoofer placement for the SB16-Ultra gave away some output in those ultra-deep bass frequencies, it was still able to bring most of power of the content of ‘Organ Sensation’ to the fore. On the occasions where the recording brought in the weight of those large pipes, the SB16-Ultra pulled that effect through with authority. It never strained at any volume, no matter how loud I cranked it. ‘Organ Sensation’ was at times beautiful and other times thunderous, and the SB16-Ultra handled both ends of the dynamic range with aplomb.

For a different kind of ruckus, I looked for something very heavy in percussion, and nowhere does one find music denser in percussion than the electronic genre of ‘Drum and Bass’ music. In this vein I listened to the album ‘Biological Warfare’ released in 2004, which is a compilation of Drum and Bass tunes by different artists mixed together by the short-lived group ‘Resonant Evil.’ The bass lines are heavy and unrelenting, and the kick drums are incessant in this genre of electronic music. A well-made subwoofer loves this constant attention, but, when the volume is loud, a poorly-made sub will be begging for mercy in an album like this. A variety of different percussion and bass sounds populate the 19 tracks over this album with none of them sharing the same instrument sounds. A good subwoofer is crucial in doing this music justice if the main speakers are not truly full-range with real capability in low frequencies (a rarity, even among some high-priced speakers). The SB16-Ultra rocked ‘Biological Warfare’. There were moments when I cranked the volume to extreme levels, and the lights that shared the 15 amp circuit with the subwoofer actually dimmed, but the subwoofer itself never eased up. The abundance of bass in ‘Biological Warfare’ came through loud and clear on the SB16-Ultra. The SB16 was able to pound my home theater room with this album with a clean, punchy sound; a bruising experience, which is exactly what the artists intended with this content.

It should be kept in mind in reading these impressions of the subwoofer’s musical experience that I took the time to find the best location for a flattest response. This position placed the subwoofer very close to my listening position, which certainly assisted in maximizing the dynamics that I experienced. If no care is given to the placement of the SB16-Ultra (or any other subwoofer, for that matter) the results can end up being a very uneven response that can make for a poor reproduction of music. Those subwoofer owners or buyers who are concerned with accurate playback would do well to take the time to find the best locations. We have several articles on Subwoofer Placement  which are great starting points for anyone interested in learning more.

Movie Listening

There are many films released nowadays that make extensive use of subwoofer frequencies, and some sound mixes would seem to overdo it to an exaggerated degree. Since this is what is being produced, I might as well use such a film to evaluate the SB16-Ultra with, since that sort of content is going to find its way to the end user at least once in awhile. One film I picked for its excessive use of bass is the 2009 actioner ‘Ninja Assassin’, an over-the-top martial arts film starring Korean pop star Rain. In this movie, swords fly by the camera with a bass-heavy whoosh, and throwing stars slice into walls with a thunderous blow. When someone gets punched or kicked, it sounds like a side of beef was just hit by a sledgehammer. The orchestral musical score by Ilan Eshkeri makes heavy use of the subwoofers as well, with lots of double string bass and bass drums adding a persistent rumble underneath the action. The SB16-Ultra brought all of this low-frequency content out with dexterity. Every bone-breaking blow was felt as much as it was heard. While its ported sibling, the PB16-Ultra, might have given the deepest frequencies a more earth-quaking shudder, the SB16-Ultra could still plumb the depths, just not with the crushing power that the PB16 brings. Nonetheless, I was definitely not left wanting for more bass in ‘Ninja Assassin’, and the SB16-Ultra dished out the pummeling that was asked of it by the sound mix.

Another movie I watched with the SB16-Ultra was the new Jason Bourne movie with the not-so creative title ‘Jason Bourne’. ‘Jason Bourne’ is the fifth film in the Jason Bourne franchise and is replete with action set-pieces including the stupendous climactic car-chase that lands it in my list as one of the all-time greatest car-chase sequences (leave a comment in our comments section if you disagree, but be warned I am prepared to defend my opinion!). Since the action scenes in the Bourne movie are more down-to-earth than most action movies, the low-frequencies are not used nearly as much as with the more outlandish ‘Ninja Assassin’ for the sake of creating a more convincing fictional universe. This isn’t to say ‘Jason Bourne’ is bass shy; it’s simply used more sparingly and therefore with a bit more subtlety for an action movie. Gun shots, roaring engines, car crashes, and panicking crowds round out the sound effects, and an intense, pounding orchestral score accompanies the action scenes. For ‘Jason Bourne’ the SB16-Ultra had work to do but, in order to fit in with the rest of the sound mix, it had to do it with more finesse than is the case with more fantastical film sound mixes. The SB16-Ultra hit hard when it needed to and had a soft touch in those moments when less-is-more. It gave the soundtrack a solid foundation without drawing attention to itself, which is what a subwoofer should be doing in a Bourne movie sound mix. I enjoyed ‘Jason Bourne’, and the SB16-Ultra helped to make that happen. 

SVS SB16-Ultra Sealed Subwoofer Measurements and Analysis

The SVS SB16-Ultra was tested using ground plane measurements with microphone at a 2 meter distance in an open setting with well over 100 feet from the nearest large structure. The sub was tested with woofer facing the mic. The subwoofer’s gain was set to maximum, and the low pass filter was left off. Weather was recorded at 58°F and 27% humidity. 58°F is a bit lower temperature than what is dictated by the CEA-2010 protocol which specifies a range of 65°F to 80°F, but the difference that such a minor change would make would be minute.

 

Frequency response of the SVS SB16-Ultra 

The SB16-Ultra’s frequency response is impressively flat. We measure a +/- 3 dB window of 18 Hz to 330 Hz. While that does not quite match SVS’s own spec of 16 Hz to 460 Hz, it is extraordinarily good nonetheless. The +/- 1 dB window is an astonishing 30 Hz to 200 Hz. This is a supremely linear sealed subwoofer. The low end seems to roll off at a slightly steeper rate than the expected 12 dB/octave slope typically found in sealed subs, and this suggests that a mild high-pass filter is implemented in the amplifier’s DSP. Some people might dismiss the usefulness of such an extended high-end response in a subwoofer as we see in the SB16-Ultra, but I do prefer having the freedom to run the speaker/subwoofer crossover higher than the standard 80 Hz without a gap in the bass response.                              

                      SVS SB16-Ultra CEA-2010 Maximum Clean Burst Output Measurements
                                             Referenced to 2 meters ground plane RMS

Test Frequency (Hz)	Max Passing Measurement (dB)	Total Harmonic Distortion (%)	Harmonic Threshold Limiting
10	83.9	14.4	3rd Harmonic
12.5	88.8	15.6	3rd Harmonic
16	94.7	17.5	3rd Harmonic
20	100.1	17.6	3rd Harmonic
25	106.4	19.7	3rd Harmonic
31.5	113.1	13.5
40	115.2	12.3
50	116.2	7.4
63	116.5	10.1
80	116.0	8.2
100	116.3	7.1
125	116.8	9.7

The above table shows the CEA-2010 measurements taken from the SB16-Ultra, which tests its burst output within certain distortion limits. They basically show how loud a subwoofer can be for a brief moment while staying somewhat clean. As always, our measurements have been referenced to 2 meter RMS, which is 9 dB down from the standard requirement for the measurements to be shown at 1 meter peak.

This is an excellent showing, particularly from 20 to 31.5 Hz. One feature that can be discerned right away is that the SB16-Ultra driver has more to give at 31.5 Hz and up, were the amplifier able to give more power. Above 31.5 Hz, this driver is taking all the juice that the 1,500 watt amp can give and is asking for more. Below 31.5 Hz, the driver can be pushed to its limits, but its performance ceiling in this respect is extremely good considering the driver diameter (SVS’s spec of a 16” is a bit generous; I measured 15.5” from frame’s edge). One interesting exercise we can do to get a sense of the differences between the overhung and underhung driver designs of the 16-Ultra driver is compare these measurements to those of the PB16-Ultra in sealed mode. We see that the sealed PB16-Ultra has more deep bass capability but the SB16-Ultra has more mid-bass capability.

Another interesting comparison we can do with the SB16-Ultra CEA-2010 measurements is put them up against SVS’s former flagship sealed subwoofer, the SB13-Ultra, reviewed by Audioholics. A couple of notable details emerge. First, we see that in the extreme deep bass frequencies of 10 Hz and 12.5 Hz, they are nearly on par, but the SB16 starts to pull ahead at 16 Hz and keeps its lead until 63 Hz. At 25 Hz and 31.5 Hz we see the SB16-Ultra has a very substantial 5 dB gain over the SB13-Ultra, nearly doubling its output. Above 63 Hz, the SB13 pulls ahead, perhaps due to a much lighter weight of its moving parts. 

     

    

   

Frequency Breakdown of CEA-2010 Burst Measurements for the SVS SB16-Ultra

The above graphs show the frequency spectrum of the increasing CEA-2010 bursts as reproduced by the SB16-Ultra. Essentially, it depicts the behavior of the subwoofer reproducing short burst tones at successively louder levels, with each test tone raised by boosting the input gain by 1 dB until no more output was to be had from the subwoofer. The frequency marked above the graphs note the fundamental tone being tested, and this can also usually (but not always) be discerned in the graphs by the horizontal axis frequency point of the “main ridge,” the highest levels on the vertical axis. The noise below the fundamental (that random spikiness to the left of the main ridge) should be ignored. What should be looked at are the smaller ridges to the right of the fundamental; these are the distortion products of the fundamental, and it is here where we see how cleanly the subwoofer handles a given output level. These are mostly harmonics: whole number multiples of the fundamental.

In these graphs, the SB16-Ultra shows itself to be an extremely low-distortion subwoofer. At low frequencies we can see that the third harmonic is always the dominant distortion product, which indicates a balanced design as far as excursion goes. The SB16-Ultra keeps things well-controlled in the deep frequencies until it is pushed to the edge of its performance envelope. This is ideal behavior, in that it gets the most out of the driver but does not let the driver fly too wildly past the point of linear excursion. In the upper frequencies, the second harmonic becomes the predominant distortion product, but it only appears in vanishingly small quantities, and certainly nothing that is audible. It is likely the result of induction, and the SB16-Ultra remains extremely clean at these frequencies even when pushed as hard as possible. This is evidenced in the CEA-2010 measurements where distortion, at its worst, was still only measured in single digit percentages for many of these frequencies. To sum up the behavior here, the SB16-Ultra has relatively clean output in deep bass for a sealed subwoofer, and no significant distortion to speak of at 50 Hz or above. Exceedingly linear performance is on display here.

  

Long-term Output Sweep Measurements for the SVS SB16-Ultra 

Testing for long-term output compression was done by first conducting a sweep tone where 50 Hz hit 90 dB with the subwoofer 2 m from the microphone. We then conduct further 20 second sweeps by raising the gain by 5 dB until no more output could be rung out of the subwoofer. In these tests we can see that the SB16-Ultra does not start to lose its shape until the 105 dB sweep, although not by much at that point. At the 110 dB sweep, the low-end rolloff rises to the mid 30 Hz range, and the response knee becomes sharper at the highest output sweep, after which the SB16-Ultra was not able to produce any more output. This compression behavior is overall pretty good. The ideal is for the frequency response to maintain its same exact shape from low output levels to the highest output level, but, of course, that will never occur in practice. In practice, however, the response of the SB16-Ultra does not change dramatically. The rolloff does hike up to about 35 Hz where some response from the upper teens to 35 Hz is lost, and that is the driver losing its EQ’d shade by running out of displacement ability.

There is a lot of output to be had here. From 40 Hz to nearly 200 Hz, the SB16-Ultra is running right along 114 dB at its highest sweep level. SPLs below that level are good as well. Using the SB13-Ultra as a point of comparison, at 60 Hz and above they have about the same output, but below that point the SB16-Ultra’s displacement advantage gives it a clear lead. From 20 Hz to 40 Hz, the SB16-Ultra holds about a 4 dB advantage, which is about a 60% increase in performance.

 

SVS SB16-Ultra Total Harmonic Distortion per Long-Term Output Sweeps 

The above graphs show total harmonic distortion for the sweeps done on the ‘Long Term Output Compression’ tests, and they essentially depict at what drive level and frequency the subwoofer loses linear playback. The performance shown here by the SB16-Ultra is very good for a sealed subwoofer of its size. As seen in the CEA-2010 testing, this is an extremely low distortion subwoofer above 30 Hz. At nominal levels of 90 and 95 dB, the SB16 hovers around 1% THD above 50 Hz, which is about as low as most popular music digs. Even when pushed to the very edge in this frequency range, it doesn’t surpass 5% THD, and this makes the SB16-Ultra a superb choice for typical music recordings. In deep bass, distortion does not go over 20% THD for 90 and 95 dB at any frequency. Once pushed to the 100 dB sweep level, it does surpass 20% THD, but is still mostly in control of itself. Below 20 Hz and above 105 dB, it does start to lose control, but few sealed subwoofers can hold it together in this performance region. There is a lot to admire here, both for mid-bass performance and deep bass performance.

    

    

Component harmonics of the SVS SB16-Ultra 

The above graphs depict measurements of the constituent harmonics from the long-term output sweeps. These are the individual harmonics that compose the total harmonic distortion graph above them. As with the burst testing, we see that the third harmonic is the chief offender here, and it mostly rears its head below 25 Hz. This is where the driver is running out of excursion, and we can see that since the third harmonic is what is cropping up above all else, that both sides of the cone’s travel are being inhibited, by either the suspension or the voice coil leaving the ‘gap’, or the region of magnetic flux that it reacts against. This distortion profile indicates a high level of optimization for the driver. The more audible higher-order harmonics are insignificantly low until the SB16-Ultra reaches the bleeding edge of its performance envelope. The overall picture here is that the SB16-Ultra will not produce audible distortion until driven to its limits, and even then it would only occur at deep frequencies. 

 

Group Delay of the SVS SB16-Ultra 

Group delay is the measurement of how much time it takes for individual frequency bands of an input signal to be produced by the speaker. It can indicate that some frequency components are developing slower than others or are taking longer to decay. It is generally thought that 1.5 sound cycles are needed for group delay to be audible at bass frequencies, although there is an argument that group delay should remain under 20 ms to be completely unnoticeable, but that is likely meant for mid and upper bass frequencies. The SB16-Ultra puts on a very good showing here. Group delay doesn’t surpass one cycle until just above 30 Hz, at which point it is far too deep in frequency to approach audible, which is still the case even as delay surpasses 1.5 cycles at just above 20 Hz. In the region where group delay would be a concern, the SB16-Ultra keeps everything below a single cycle. The SB16-Ultra sounded tight and didn’t exhibit any overhang in my listening sessions with it, and this graph explains why. This sub is as sharp as a tack.

      

Low-Pass Filter Effects of the SVS SB16-Ultra 

The above graphs simply show the effects of some of the low-pass filter settings, with the left graph showing the range of frequencies that can be filtered and the right graph showing the effects of the different slopes. The SB16-Ultra has a low-pass frequency range of 30 Hz to 200 Hz using slopes of 6, 12, 18, and 24 dB per octave rolloffs. For those not using external bass management, the SB16-Ultra should be able to find a frequency and slope that will help it blend in with the main speakers seamlessly due to the very fine adjustments that can be made with its low-pass filter.

SVS SB16-Ultra Sealed Subwoofer Conclusion

Usually in the conclusion of these reviews, I start out with a list of the aspects of the review product that I feel are particularly good and aspects that I think could use some improvement. I usually start with the negatives before I go into positives. However, with the SB16-Ultra, there really aren’t any significant negatives. I have very little to complain about with this subwoofer. The only thing that I wish was different is the weight, because moving the SB16 is a chore. Two people are needed to safely lift it and carry it anywhere. You don’t want to drag it, because the rubber tipped feet will leave marks on the floor. The SB16 is built like a tank, but as a result, it also weighs as much as one. I wish there was a way that SVS could shed some weight on this beast without sacrificing any aspect of its performance or build quality. Perhaps they could use Neodymium magnets in the motor instead of a stack of ferrite slugs, but that would entail a very significant price hike. A lot of people have the idea that massive over-building equals build quality, but I don’t think this is necessarily so. Rather, I think intelligent construction choices equals build quality. In the SB16, there is a bit of both; I see some very intelligent design choices, but I think there is also some over-building just for the sheer physicality of it. For example, did the front baffle thickness really need to be 2” thick? Did the side panels and bracing really need to be 1” thick? They don’t look to serve a purpose beyond adding mass, and it all adds up to a daunting 122 lbs. weight.

Picking up the SB16-Ultra is akin to trying to lift a boulder, but a boulder that has a very fine finish that I do not want to get even a small scratch on; it’s not easy! However, this is not a major complaint against the SB16-Ultra. It is heavy but not unmanageable. Most people will already have a place allocated for it, and they plop it down there and rarely move it after that. My complaint about weight may also have something to do with the fact that, as I get older, I am finding that I don’t lift things like this as easily as I used to.

Outside of my nitpick about its weight, I don’t have anything else to gripe about. It has great performance, great looks, and brains too, on account of the very sophisticated DSP programming that has gone into it. It is, as they say, ‘the whole package.’ On the performance front, its greatest advantage is in deep bass, specifically from 16 Hz to 30 Hz. I doubt there is any sealed subwoofer using a cone diameter of less than 18” that can match it in this area. Above that range, there are similar-sized sealed subs that can match it for loudness, but it still has supremely low distortion in mid-bass regions, and it is no slouch in output in this range as well. In the looks department, as I have repeatedly mentioned, it looks fabulous with its gorgeous finish, slick cabinetry, lustrous cone, and cool front display screen. As for the ‘brains,’ you can use its digital processor to shape the response into nearly anything you want. There is a host of room compensation curves, a 3-band parametric equalizer, and an extremely flexible low-pass filter, and, on top of all of that is the ability to set the gain and the phase to very precise values. The digital processing allows the SB16-Ultra to be finely integrated and calibrated for a wide range of different conditions, and it can all be done from your smartphone or tablet.

We are going to award the SB16-Ultra our Bassaholics ‘Extreme’ room rating, despite it not quite hitting the required burst test measurements. It only missed them by approximately 1 dB, and its performance is so exemplary in many other respects that we feel it would handle a very large room size. The ‘Extreme’ room rating certifies that this sub will be able to handle a room size of 5,000 cubic feet. Information about how this room rating was established can be read in the article: Bassaholic Subwoofer Room Size Rating Protocol. However, those who like their bass to be massive might want to use more than just one. Indeed, for a smooth frequency response in-room, multiple subwoofers are usually a requirement, and two or more SB16-Ultras would make for a tremendous system.

    

To bring this review to a close, in my evaluation I would say the SB16-Ultra is a top-notch subwoofer. It is expensive, but in addition to the subwoofer itself, you get a 5-year warranty and some of the best customer service in the industry. For those who are on the fence about the SB16-Ultra, you can try one risk free, since SVS will issue a full refund and pay for return shipping if you decide not to keep it for any reason with 45 days of receiving it. I think the vast majority of people who give it a try will end up keeping it. I can say that I am reluctant to send my review sample back!

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Bass Extension
Bass Accuracy
Build Quality
Fit and Finish
Ergonomics & Usability
Features
Dynamic Range
Performance
Value