SVS PB16-Ultra Ported Subwoofer Review

PB16-Ultra Introduction

The PB13-Ultra has long been SVS’s flagship subwoofer, and over the years, has often been mentioned as one of the ‘top dogs’ of subwoofers. i.e., one of the best commercial subwoofers available. While it still remains a superb choice in its price range, there have been many developments over the years, and competing subwoofer manufacturers now offer some powerful and appealing alternatives.

SVS has not been known to rest on their laurels, but it had been so long since the launch of their last top-end subwoofer that the announcement of the new 16-Ultra series took many of us in the audio community by surprise. SVS has touted their new 16-Ultra series as the most advanced subwoofers in the world, so we were very excited to have SVS send us their new ported super-sub for review, the PB16-Ultra. So without further ado, let’s dig into the PB16-Ultra and see how much of a subwoofer SVS can bring to you for a cool $2,500.

Unpacking and Setup

          

The PB16-Ultra ships via freight and the box arrived strapped to a pallet. The shipping weight is a staggering 207 lbs., so multiple people will be needed to move it inside the residence if there are steps or stairs leading into the residence. The box has built-in handles that make moving it manageable for two people once off the pallet. The boxed subwoofer should be placed near where the unpacked subwoofer’s final destination is intended to be, and the reason for this is because it is easy to scoot the sub there in the internal packaging, and once the subwoofer is placed there, the user will not want to move it around much afterward due to the weight. Unpacking instructions are contained inside the inner flap of the box, but all the user has to do is open the forward and rear box ends and slide the sub out of one end by pushing it from the other side. The PB16-Ultra is well packed, and a lot of thought was put into how to easily unpack such a heavy and large subwoofer. I was worried about how I was going to handle unpacking such a bruiser, so SVS’s efforts are well-appreciated here.

Setting up the PB16-Ultra is not especially complicated even though there is a lot going on with it. There is a quick start guide, but I would encourage users, especially novice subwoofer owners, to go through the owner’s manual. It covers the operation of the subwoofer thoroughly, provides good placement advice, and it even helpfully reminds users not to eat the battery to the remote control (it is toxic!).

Appearance  

  

While the sheer size will doubtlessly be a turn-off for some people, the fit and finish are impeccable. This is about as nice as a large ported subwoofer can look. The piano gloss finish and rounded edges go a long way towards making it aesthetically acceptable for those who might normally balk at such a bulky object. A slanted, top-mounted display that is sunk into the top front edge adds a nice, almost automotively-styled touch. The glass fiber laminated cone has a hypnotic sheen with ‘SVS’ imprinted in the center. SVS has provided a rounded metal grille, but it is a drab grey texture, and the PB16-Ultra looks much better without it. One slight nitpick: I would have preferred a magnetic grille so that there would be no visible sockets for the grille guides, but that would not have been possible for the heavy-duty grille that SVS provides. SVS has tried to make a large ported enclosure as palatable as possible, and they have done a stellar job.

Design Overview

The PB16-Ultra design shares many design similarities with the PB13-Ultra, and, at a glance, one might make the mistake of thinking it is merely a larger version of the PB13-ultra. However, under the hood, there are some radical departures from the PB13-Ultra, which we will discuss in a bit. First, let’s discuss the obvious similarity, the enclosure design. The PB16-Ultra is a front-firing, triple-ported, variable tuned subwoofer. It has three modes of operation: three ports open, two ports open, or sealed, which according to SVS, have respective -3 dB points of 17 Hz, 14 Hz, and 21 Hz. For those who are new to subwoofers, what this means is that when one of the ports are sealed with an included port plug, the subwoofer can play back deeper bass frequencies, although it comes at the expense of louder deep bass. Sealing all the ports, however, eliminates a lot of the deep bass output altogether. A single port open mode was not supported by the PB16-Ultra, perhaps because port turbulence would occur too easily with that much air displacement versus so little port volume.

 

While the PB16-Ultra enclosure design doesn’t break any new ground for SVS, the driver design is a major change, and not just for SVS but for most commercially manufactured subwoofers. Putting aside the slightly unconventional woofer diameter of 16”, it uses a very unusual motor structure. We described this in our preview article for the 16-Ultra series:

...what really stands out in the specs is the use of a 8” diameter voice coil. For those who are not intimately familiar with subwoofer driver specs, we will briefly try to explain why this is so striking. The voice coil is what handles the electrical current sent from the amplifier. It is a coil of copper wire that produces an alternating magnetic field when electrically charged. That magnetic field interacts with the magnetic field of a powerful permanent magnet in the motor of the driver, and this is what causes the woofer to move back and forth. Typically the voice coil is wound on a cylindrical piece called the former which is set inside the permanent magnet, so the diameter of the former and thus the voice coil is usually not very big; 2.5” to 4” are common coil diameters for drivers in the 15” to 18” cone range. The SVS 16-Ultra drivers flip this around and sets the coil outside the permanent magnet. Since the magnet for a monster driver like in the 16-Ultras has to be very big, this means the voice coil must be large, and an 8” voice coil is unheard of, especially for driver with a 16” cone. The potential advantages are many: superior heat dissipation which lessens thermal compression and increases power handling, better centering of the former for a more restricted plane of motion for less distortion and less chance of tilting at high excursions, increased stiffness of the cone since there is more contact and more widely spaced contact between the former and cone, more efficient use of the permanent magnet’s field, and more room for excursion by the former since it trades height for width.

Another notable characteristic of the PB16-Ultra driver is the use of an underhung voice coil, although this is not quite as radical since it was also used in the PB13-Ultra. A voice coil being underhung means the height of the coil winding is not larger than the magnetic gap that the coil travels in (a more thorough explanation can be found in this article). The advantage of this approach in the PB16-Ultra is an underhung coil can grant more linear excursion, and this seems to be the case with SVS’s claimed linear excursion of 82 mm peak-to-peak, giving it a tremendous 41 mm of xmax, which is the largest xmax I have ever heard of for a commercial subwoofer using a cone of 18” or less.

    

The cone is made from a very pretty glass fiber laminate with a reinforced composite cone sub-structure, and is connected to the cast aluminum basket by a large rubber surround and a very large nomex spider. Two shorting rings are used to reduce inductance and therefore even-order harmonic distortion. The motor uses four stacked ferrite magnets, giving the motor section itself a 56 lbs. weight, which makes up the majority of the driver’s tremendous 63 lbs. Normally in this section of the review I would remove the driver to take some pictures, but, due to the weight, the driver is mounted in a special manner that makes removing it a very cumbersome process, so we will use driver pictures that SVS has provided us.  

Along with major advances in the driver department, SVS has added innovations in the amplification as well. To power such a beastly driver, the PB16-Ultra uses a 1,500-watt, class-D Sledge amplifier. The amplifier is so jam-packed with features that instead of trying to list them all, I will touch on a few of the highlights. The amplifier can be controlled by either the front LED display, remote control, or by SVS’s smartphone app. One neat thing about the smartphone app is the ability to manipulate the frequency response with a parametric equalizer. In fact, nearly every aspect of performance can be controlled by SVS’s app, which is nice for those who like to endlessly tweak their sub, since now they can do so from their sofas. The amplification uses a fully discrete MOSFET output stage instead of an integrated circuit output stage. MOSFETS offer better bandwidth and lower distortion than the op-amps typically used in class D amplifiers, especially for the enormous current that the 16-Ultra drivers can pull in. Processing is done by a 50Mhz Analog Devices Audio DSP with double precision 56bit filtering, which sounds like more processing power than is needed for low frequency sound waves. However, since processing power is so cheap nowadays, why not? The PB16-Ultra has both XLR and RCA inputs and outputs, so connectivity with any modern device poses no problem. High-level inputs and outputs might have been nice for older or simpler setups using integrated amps, but those types of setups are becoming increasingly rare, so I cannot fault SVS for omitting those connections. 

When people describe their subwoofer cabinets, the cliche ‘built like a tank’ is often used. With respect to the PB16-Ultra, ‘built like a tank’ doesn’t even quite describe it. Imagine the biggest heaviest tank ever made, and then maybe we have an apt comparison for the PB16-Ultra. (Minor digression: a Google search says the heaviest tank ever made is the WW2 German prototype Panzer VIII Maus, weighing 188 tons!) The PB16-Ultra is constructed with 1” MDF sides and internal bracing and 2” thick in the front baffle. Two window braces are set near the center of the sub with one of the braces wisely supporting the motor section of the driver and the other supporting the ports. A generous layer of stuffing lines the cabinet all around to help damp resonances. The grille is very heavy and tough; it really will help protect the woofer and ports from children and pets. It is like a plate of armor for the front of the sub, making the tank analogy even more appropriate. To support the full weight of the PB16-Ultra, SVS used six rubber feet instead of four, with two feet supporting the midsection.    

SVS PB16-Ultra Subwoofer Listening Tests

The PB16-Ultra is so large, I didn’t have much of a choice in places where it could go; I set it behind my sofa. The resulting frequency response was not as bad as I had anticipated, with a very narrow but deep dip at 60 Hz and a broad but shallow dip at 30 Hz. Receiver used was a Pioneer Elite SC-55 with some Fluance Signature tower speakers, with the crossover set at 80 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 

A pipe organ album recommended for some powerful bass tracks is “King of Instruments: A Listener’s Guide to the Art and Science of Recording the Organ” which is a compilation of recordings made from different pieces played on different organs. Some of the pieces turned out to contain very powerful bass fundamentals all the way down to 20 Hz, no doubt one of the reasons why the organ is nicknamed the ‘King of Instruments’. Many of the tracks can present a massive tower of sound, with layers of low-frequency harmonics accompanying a deep fundamental. The SVS PB16-Ultra captured these dense low-frequency passages with the utmost fidelity. The power of the PB16-Ultra (and also its near-field placement) lacked for nothing in recreating the colossal bass sound of these mighty instruments; there were moments that it vibrated my entire sofa. Indeed, it is as if, musically, the PB16, with its deep tuning frequencies, was made for the pipe organ, since no other natural instrument can dig as deep or play low frequencies as loud. Pipe organ lovers will truly appreciate what the PB16-Ultra can do here, and I can also recommend the album ‘King of Instruments’ to pipe organ enthusiasts as well; a great recording played back on a great speaker system makes for a marvelous experience.

    

For something much less traditional and more on the experimental side, I turned to the album ‘Throne of Drones’ which is part of a series of dark experimental soundscapes from the recording label Asphodel. These albums are good for gauging a subwoofer’s capability due to the often finely textured low-frequency content in some of the tracks. The music itself sounds like a soundtrack to a tour of a long-dead city of an advanced alien civilization; it is atmospheric, exotic, and gloomy. The bass in this recording can take many shapes: a subtle background hum, a blast of vibrating buzz, a distant cavernous rumble, or an all-encompassing growl. The PB16-Ultra deftly handled everything and anything that was thrown at it with equanimity. It gave some tracks a positively subterranean feel, as though my room had fallen into the depths of the Earth. For a high-fidelity subwoofer like the PB16-Ultra, this music must be like a high-grade road course is to a high-performance car; a prospect to relish that a lesser performing unit would fear to tread.    

Taking a 180° turn, I turned to something a bit more boisterous. For loud, frenetic, and hard-hitting, it would be difficult to top the drum’n’bass group Counterstrike, so I queued up the album ‘From Beyond the Grave’, a 2005 monster of a recording. For its time, it was the extreme end of an extreme genre of electronic music: an absolutely ferocious album with a very high tempo, very dense percussion, and very heavy bass lines. It is to electronic music what death metal is to rock music. Out of a sense of masochism, I cranked the subwoofer output 9 dB hot with the master volume set to reference and braced myself for a beating. On the PB16-Ultra, ‘From Beyond the Grave’ pounded. Kick drums punctuated the nearly constant bass line, and the PB16 made sure it was all felt as much as it was heard. With the PB16-Ultra firing into the back of my sofa, it felt like sitting in a massage chair that had gone insane. It was a bruising and distressing experience that left me deeply traumatized, but it was also a whole lot of fun. The PB16-Ultra was certainly up to the task of dishing out a savage beating when asked. If you can set aside some time for trauma counseling afterward, I can heartily recommend Counterstrike’s ‘From Beyond the Grave’ as blasted through a SVS PB16-Ultra.

Movie Listening

A subwoofer built for such deep frequencies deserves to be paired with content built for deep frequencies, and there is no content I know of that has such sustained deep bass as 2010’s ‘Tron Legacy’. Most reading this will likely be familiar with this film about a young man’s adventure through a computer generated world (which seems to be the same situation as almost every major film nowadays, but in ‘Tron Legacy’ this is the actual plot). However, those who have only heard it on a typical home audio system have only heard half the movie, since there is so much low-frequency energy beyond what most systems are capable of reproducing. That certainly is not the case with the PB16-Ultra, as I found out when I used ‘Tron Legacy’ to see what this sub could do. Between the thunderous effects sounds and Daft Punk’s relentless score, ‘Tron Legacy’ is filled with all kinds of bass from opening credits to end credits. At high output levels, this is a soundtrack that will beat lesser subwoofers into submission, but the PB16-Ultra took everything that ‘Tron Legacy’ could throw at it with ease. Not only did it crank out bass so visceral I could feel it in my chest, but it did it gracefully, with nary a hint of stress or strain. A lot of fun was had on movie night watching ‘Tron Legacy’ with the PB16-Ultra. “Tron Legacy’ is a great demo movie for the PB16-Ultra, and the PB16-Ultra is a great subwoofer to demo ‘Tron Legacy’s epic low-frequency sound mix.

    

Another film I watched with the PB16-Ultra was the 2014 World War 2 film ‘Fury’, which is about an American tank crew fighting in Germany towards the end of the war. I decided on ‘Fury’ due to the more naturalistic bass sounds involved, as opposed to many of the science fiction and comic book movies where the sounds can be unearthly and are totally invented by the director and sound designer. ‘Fury’ is no slouch in the LFE department, but no movie about tank warfare should be lacking in low frequencies. I watched ‘Fury’ at a high volume and, with the PB16-Ultra only a foot behind me, and the experience was utterly concussive. Every blast from the turret cannon was felt, as was every round fired from the .50-cal heavy machine gun, every mortar shell and artillery detonation. If the aural experience of watching this in a home theater was rough, I can only imagine what it sounded like for actual tank crews in World War 2. It must have been hellish. While there were many different types of bass sounds during the battles, the PB16-Ultra sorted them out nicely. The tank engine rumble, machine gun fire, cannon impacts, grenade blasts were all separate and distinct low-frequency sounds, whereas a lesser subwoofer might have blurred them altogether into a boomy mess. ‘Fury’ has a grim tone as a movie, but the action scenes are undeniably exciting and well-directed, and a high-quality, high-performance subwoofer like the PB16-Ultra is needed to get the full experience that this movie has to offer. Besides, what is more appropriate content for a subwoofer that is built like a tank than a movie about a tank?

SVS PB16-Ultra Subwoofer Measurements and Analysis

The SVS PB16-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 and ports facing the mic. The subwoofer’s gain was set to maximum, and the low pass filter was left off. Weather was recorded at 63°F and 63% humidity.

 

Frequency responses of the main operating modes of the SVS PB16-Ultra 

The frequency response graphs of the modes of the PB16-Ultra demonstrate it to be a very accurate subwoofer. One difference between our findings and SVS’s specs occurs in the high end, where SVS’s claims a +/- 3 dB point out to 280 Hz in the ported modes. We see a big drop right after 200 Hz, but that can hardly be a point of complaint for a subwoofer, since that is already an above-average high-end extension that isn’t likely to be taken advantage of as it is. Keep in mind the scale when viewing this response graph; that is a 2 dB tick marks for the vertical axis, which is a very unforgiving scale, and the response is not smoothed at all. The PB16-Ultra is such a high-performing and accurate subwoofer that I feel it can bear this level of scrutiny easily. What is shown is a highly linear response from below 20 Hz to just above 200 Hz in all modes; while this is standard M.O. for SVS, few other subs sport such a flat frequency response. There is a small uptick in output at the tuning points, but this is slight, and will likely only be perceived as beefing up the deep end of certain effects sounds. If room gain boosts the deep end too much for certain tastes and the sealed mode does too much to damp deep bass output, there are a variety of room compensation curve adjustments that can be accessed from the SVS subwoofer app. The frequency response is very malleable, thanks to SVS’s programming options. Some users may even want to boost the low end with the parametric equalizer to give rumble effects even more grunt. As will be seen in below measurements, the PB16-Ultra has the low-end headroom and built-in self-protection to sustain that kind of response. 

SVS PB16-Ultra CEA-2010 Burst Test Measurements
	Standard Mode (3 ports open)			Extended Mode (2 Ports Open)			Sealed Mode
Frequency (Hz)	SPL (dB)	THD + N (%)	Harmonic limit	SPL (dB)	THD + N (%)	Harmonic limit	SPL (dB)	THD + N (%)	Harmonic limit
12.5	-			89.1	16.1	3rd, 9th	89.8	15.1	3rd
16	100.0	20.3	3rd	109.1	8.2		97.1	21.5	3rd
20	113.8	11.8		112.3	15.5		103.2	23.9	3rd
25	116.9	2.7		115.5	5.4		109.7	22.2	3rd
31.5	119.5	7.6		118.0	9.7		114.7	17.4
40	120.3	11.5		118.8	9.3		116.1	13.6
50	119.4	11.3		118.4	11.9		116.6	13.5
63	117.7	7.8		117.1	7.1		115.7	6.6
80	115.6	3.9		115.0	4.9		114.0	6.3
100	113.9	6.1		113.6	6.5		113.0	7.5
125	112.8	5.4		112.7	5.4		112.2	6.0

The above CEA-2010 measurements are short-term bursts that show the subwoofer’s clean peak SPL before heavy distortion sets in. 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. However most publically available CEA-2010 measurements are shown at 2 meter RMS, so we followed that convention.

Some interesting features emerge in our CEA-2010 results. We see massive output potential at 63 Hz and below, topping out at a staggering 120 dB at 40 Hz in standard mode. The 109 dB measurement at 16 Hz in Extended Mode is also rather spectacular. When we compare the upper bass frequencies to the deep bass frequencies, we can see where SVS’s heart lay. While the mid and upper bass output isn’t bad, it is 50 Hz and below where the PB16-Ultra really shines. A subwoofer like this is especially comfortable with deep bass content as in the film ‘Tron Legacy’.

It is also interesting to compare these numbers SVS’s measurements for their former flagship subwoofer, the PB13-Ultra previously reviewed, to see if they achieved the performance gains they were after. At 50 Hz and below, we see a gain of 2.5 to 5 dB depending on frequency, which means a 33% to 80% increase in performance respectively. At 63 Hz to 80 Hz, the performance increase over the PB13-Ultra hovers around a 1 dB gain, and the PB13-Ultra manages to outperform the PB16-Ultra slightly in upper bass at 100 and 125 Hz, although those high frequencies are less consequential since few people will be using a crossover that high. I would speculate that the relatively high moving mass of the PB16-Ultra driver (the cone, voice coil, and former) in combination with the underhung design diminishes the upper bass sensitivity; this is the trade-off made for the enormous excursions needed for monster deep bass while keeping the size and weight of the unit manageable so as not to need a forklift to move. Readers considering the SB16-Ultra subwoofer should note that subwoofer uses an overhung voice-coil and lighter-mass driver, as opposed to the underhung driver of the PB16-Ultra, and that design type should have more upper bass capability than the PB16-Ultra, so they would be in error to judge the SB16-Ultra’s performance from our measurements of the PB16-Ultra.  

A couple more notable aspects of these measurements: we can see that the PB16-Ultra driver has a very large displacement advantage over the PB13-Ultra driver from comparing the low-frequency sealed measurements where the largest gains are made. Also, as is the norm with SVS, the harmonic distortion is extremely low. This is remarkably clean bass even though the subwoofer is being pushed to its maximum limits. Only a handful of these measurements are capped by the CEA-2010 distortion thresholds. It is a rare subwoofer that can churn out low frequencies this loud at such low levels of distortion.

    

Frequency Breakdown of CEA-2010 Burst Measurements for the SVS PB16-Ultra

The above graphs show the frequency spectrum of the increasing CEA-2010 bursts as reproduced by the PB16-Ultra in Extended Mode. 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 either 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.

These graphs show us the extraordinarily low distortion that the PB16-Ultra produces at nominal to high drive levels. At the test frequencies below the port tuning, 10 Hz and 12.5 Hz, there is a lot of heavy distortion, but that would be expected as it is outside the subwoofer’s intended range of operation. Above those frequencies, we can see greater than 30 dB differences between the fundamental and the largest distortion product at medium to high drive levels, meaning the total harmonic distortion is lower than 3%. That is extremely low, well below anything remotely audible. The predominant distortion product is the 3rd harmonic, but, even at the highest drive level, it is still not that bad, and, from this, I would guess that the driver still has a bit more linear headroom for more power than what it is being given at many of these frequencies.

     

Long term output sweeps of the SVS PB16-Ultra in different operating modes 

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. Looking at the results, the PB16-Ultra doesn’t start really start losing its response shape until the 115 dB sweep. In the sweep above that, a bit more output can be had between 30 to 60 Hz, but everywhere else is tapped out. As with the burst tests, these long-term tests indicate the frequency band where the PB16-Ultra is the most capable: the region from 30 Hz to 60 Hz. While zero compression at all drive levels is the ideal, having extra headroom in this frequency band is not bad since it is where most movie sound effects lay. It should be noted that in this most brutal of subwoofer tests, the PB16-Ultra never made any straining noises or gave any indication that it was being badly stressed. It remained composed and in control of itself at all times.

     

SVS PB16-Ultra Total Harmonic Distortion per operating mode and output level 

The above graphs show total harmonic distortion, essentially depicting at what drive level and frequency the subwoofer loses linear playback. The performance on display here by the PB16-Ultra is superb. At 90 and 95 dB drive levels distortion wavers between 1% to 2% from 20 Hz to 100 Hz in the ported modes. In that same frequency range at the highest drive levels, distortion still remains below 10%, even when the sub is outputting 115 dB+ sound levels. 10% THD at these frequencies is not likely to be audible. Below the tuning points, distortion skyrockets, but output plummets as well, so that wouldn’t present a problem. Since the driver has to carry the entire output load in sealed mode, more distortion crops up in the lower frequencies there, but the sealed distortion profile is still quite good, with vanishingly low distortion down to 20 Hz up to the 100 dB sweep level. A limiter can also be seen in action in sealed mode where distortion goes back down below 16 Hz at the 100 dB sweep level and above. Like our other measurements show, the PB16-Ultra produces some remarkably clean bass.  

      

Component harmonics of the SVS PB16-Ultra for each operating mode 

The above graphs depict measurements of the constituent harmonics from the long-term output sweeps and is what the total harmonic distortion measurements are composed of up to the fifth harmonic. There aren’t any surprises here; the third harmonic is the dominant harmonic, and, as the sub is pushed harder, more distortion is generated in the low end. One slight oddity is that the second harmonic actually decreases as a percentage at the highest sweeps, and I don’t know why that would be, except if maybe the limiter became more active above a certain output level. The third harmonic of the sealed mode graphs nicely illustrates how hard the driver is being pushed for the given output level, although we do see the high-pass filter in action in the lowest measured frequencies, as in the THD charts.

 

SVS PB16-Ultra group delay per operating mode

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 PB16-Ultra presents nothing to worry about. Group delay does not even surpass 20 ms until 40 Hz, at which point it is much too deep in frequency to be audible. By the point that the group delay passes one wave cycle, the frequency is too deep to make a difference. For the range where it is important for group delay to be kept under control, the PB16-Ultra manages it very well. Stored energy is kept to a minimum where it would impact sound quality. This matches my subjective impression of the PB16-Ultra as having very tight bass with no overhang.

 

Sampling of some of the effects of the PB16-Ultra low-pass filter

The above graph depicts just a few different effects that can be had on the frequency response of the PB16-Ultra’s low-pass filter. With a choice of any frequency from 30 to 200 Hz and a slope of 6, 12 24, and 48 dB per octave rolloff, the low-pass filter can be tailored to any upper-end rolloff shape. The PB16-Ultra can be tweaked to seamlessly cross over in any system that lacks modern bass management.

SVS PB16-Ultra Subwoofer Conclusion

SVS has called the unveiling of the 16-Ultra subwoofer series the “most important product launch in SVS history” and has claimed that the 16-Ultras are the most advanced subwoofers in the world. These are some pretty lofty claims, to say the least, and will probably be dismissed by many people as marketing hyperbole. However, after spending time with the PB16-Ultra, I think there is merit to SVS’s statements. The PB16-Ultra is a major step up from the PB13-Ultra while only costing 20% more and is well worth the extra cost. I also can think of no other subwoofer with as long a list of features. From innovations in driver technology, amplifier technology, and controller technology, the PB16-Ultra is a step forward in every aspect of its design. I can’t think of any subwoofer that has this degree of sophistication. Some subwoofers can match its advances in one aspect or another, but the PB16-Ultra pushes the envelope in almost every respect.

Before wrapping this review up, I think this is a good place to list my criticisms and compliments. I will start with criticisms, as I personally always want the bad news before the good news. The foremost problem I had with the PB16-Ultra was safely managing its size and weight; it is not an easy task. This is compounded for this reviewer, since I have to take it out and drive it to a special location where it can be properly tested, but a typical user will not be faced with that challenge. However, if an owner has to move or ends up selling it, transporting it without scratching or denting it is not a casual matter, and the logistics must be carefully planned beforehand. Another potential problem about its size is that it needs a lot of floor space. Anyone looking to get one should do a mockup of its size to insure that it will fit its intended location. As we discussed earlier, it is not a subwoofer that can be easily hidden, so potential owners should be sure that their significant other is cool with it before purchase, as it would be a headache (and backache) to repack and return otherwise.

A minor complaint is that while the PB16’s mid-bass output is good, it is not quite great like its deep bass output. It is all very clean and articulate, but frequencies above 60 Hz just don’t quite have the staggering output that they do below that point. Users with mid-bass capable speakers and sufficient amplification may want to try a 60 Hz crossover point if they want more ‘slam’ in that band. This is a minor complaint, because the mid-bass isn’t bad -115 dB at 2m is nothing to sneeze at-, and also most people who can afford a $2,500 subwoofer likely have powerful main speakers that can handle this region if they want more output there. After all, pairing the PB16-Ultra with some diminutive bookshelf speakers would be an absurd and lopsided system, since the bass capability would be so far beyond that of the mains. While the mid-bass performance was measured to be not as powerful as its deep bass performance, that is not something I noticed during actual listening. It was not something that stood out, and I doubt that anyone throttling the PB16-Ultra to thunderous levels would be able to discern that the 80 Hz output is a few decibels down from its 40 Hz output.

With the critical comments out of the way, let’s get on with the compliments, because the PB16-Ultra has much to admire about it. The highlight for me was the extremely low distortion for the quantity of bass on tap. This is not an easy trick to pull. 16 Hz at 109 dB with only 8% THD should be considered one of the wonders of the modern world. That has to be the cleanest and loudest bass in such a deep frequency that can be physically generated out of a cabinet of that size, at least with conventional loudspeaker designs. This is the outstanding performance you get from a heavily optimized system and easily earns our Bassaholics ‘Extreme’ room size rating, meaning this sub is suitable for rooms over 5,000 cubic feet in volume.

Along with the superb performance, you get an exceptional amount of fine control over that performance via SVS’s subwoofer app and the multiple tuning modes. Here are just a few of the aspects one can control with the app: the low-end slope can be adjusted with room compensation curves, multiple peaks in room response can be trimmed with the 3-band parametric equalizer, the gain can be precisely set, the phase can be precisely set to any degree between 0 and 180, and the sub can be seamlessly blended in with virtually any speaker with the powerful low-pass filter. This can be done for multiple 16-Ultra subs individually, so you can control any and all 16-Ultra units separately from your smartphone or tablet. 

In the compliments column, I have to mention once again that the sub does not allow itself to be overdriven into danger. The limiter is bulletproof, so owners can crank it as hard as they want to impress visitors, and it will survive. That being said, putting it or any subwoofer or speaker on full throttle all the time will eventually kill it, so if you do find yourself frequently driving your sub to its limits, whether it be the PB16-Ultra or any other model, it will eventually die. The heavy protection that SVS has given the PB16-Ultra will only postpone that demise. However, in short bursts, the PB16-Ultra is pretty much indestructible.

Moving down the list, there is the gorgeous piano black finish and overall attractive cabinetry. The PB16-ultra is a large sub, but it is also a nice-looking sub. The shipping packaging is very well thought out, and owners would do well to hold on to that packaging. Owners get a 5-year transferable warranty, which is above the norm for electronics warranties. This is a part of SVS’s ‘Customer Bill of Rights’, which is a nice list of customer services offered by SVS, but other companies do offer many of the same customer services, although they do not tout them in such a grandiose manner. One ‘right’ that PB16-Ultra owners will likely not be able to take advantage of is the one year trade up policy, where an owner can trade their product in for credit toward a more expensive model; I can’t imagine SVS releasing anything more expensive or larger than the PB16-Ultra, but hey, who knows what the future holds (PB21-Ultra anyone?) By the way, if you decide not to keep the PB16-Ultra within 45 days of receiving it, SVS will foot the bill for return shipping. With as much as it costs to ship that behemoth, that return policy indicates that SVS is very confident in their product.

To bring this review to a close, I have to say after spending time with the PB16-Ultra, I am a big fan of it. SVS has taken clean deep bass to another level from their previous efforts, and those who looking for high-output, low distortion, deep-frequency bass from an upscale cabinet have a terrific new option to choose from. SVS surely has another winner on their hands, and I am expecting to see PB16-Ultras in pictures of room setups across the country before long.

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
Ergonomics & Usability
Features
Dynamic Range
Fit and Finish
Performance
Value