SVS PB17-Ultra R|Evolution Subwoofer Review

SVS PB17-Ultra Introduction

I remember the last time I dealt with a flagship SVS subwoofer, the PB16-Ultra. I was extremely excited to receive it, but it was the heaviest and largest subwoofer I had handled up to then. Moving it around and transporting it to and from my outdoor subwoofer testing site was a major pain. All of its corners and edges were rounded, and that, combined with its gloss finish, made it like handling a gigantic bar of slippery soap that I really didn’t want to drop because it was very pretty and expensive. It didn’t help that its feet were hazardously tiny for its 174 lbs. weight, so merely picking it up and setting it down could be tricky. I took great precautions to safely transport it from my vehicle after a day of groundplane testing, but nevertheless, it still slipped from my grasp and fell onto its corner. The fall shattered the gloss coating in that corner and while the damage was cosmetic, it was certainly unsellable in that condition and probably led to the enclosure being scrapped. SVS was thankfully very understanding of my predicament, but after that incident, I decided not to review any subs over 150 lbs., because they are so difficult to handle, and I didn’t want to wreck another great subwoofer like that unfortunate PB16-Ultra. That anecdote may lead to the question, why then am I now reviewing SVS’s latest monster, the PB17-Ultra R|Evolution? The answer is that I am so intrigued by the changes that SVS has claimed to have made in this new flagship sub that I am more than willing to accept the headache involved in the logistics of moving around such a massive beast. So let the games begin!

I have to say, the name of the subwoofer itself is a bit convoluted, specifically the ‘R|Evolution’ part. Something can either revolutionize or evolve, but not both unless the revolution itself is what evolves. Perhaps that is what SVS meant. The ‘PB17-Ultra’ part makes a lot more sense as a naming convention, although it defies the naming convention that SVS uses up to this model line, i.e., ‘1000,’ ‘2000,’ ‘3000,’ and ‘4000.’ By that scheme, SVS should have called this the ‘PB-5000’ but they reserved that for their newest subwoofer line. Instead, they have stuck with their older naming convention, and I would guess that is because the 16-Ultra name was already so established. In its name, the ‘P’ stands for ‘ported,’ the ‘B’ stands for ‘box, the ‘17’ stands for driver diameter in inches, and the ‘Ultra’ indicates that it stands as the top dog of SVS’s product lines. So the PB17-Ultra part makes sense, but how are you supposed to even pronounce ‘R|Evolution?’ But enough about the name; let’s talk about the sub itself.

As we will talk about in our design analysis, the PB17-Ultra makes some major improvements over the outgoing model. It has a larger driver, more powerful amps, and new DSP features. SVS claims it's a ground-up redesign, but it still has similarities to its predecessor, and that leads to the question: is this really a ‘revolution’ or is it merely an ‘evolution ’? Let’s now dive in to find out…

SVS PB17-Ultra R|Evolution Subwoofer Packing and Appearance

  

SVS has always had some of the most intelligent packing in the business as far as large subs go, and the PB17-Ultra does not depart from this practice. In fact, the packing is largely the same as the PB16-Ultra’s, a very good thing indeed, since that was the easiest large sub that I have had to unpack. A heavy-duty exterior box contains an interior package that slides out, after which, two lower pieces that hold the sub up can be slid out from under it, and the sub can be gently lowered into place. The sub does not have to be lifted out of any packing at any point, an achievement for which the buyer’s back will be thankful. The sub is covered by a cotton sleeve to protect it from scuffs and scratches, and the cotton sleeve is covered by a plastic bag to protect it from moisture.

   

Once unpacked, the PB17-Ultra is revealed to be a handsome if somewhat daunting block of a sub. It can be had in either black oak or gloss black, and I received the gloss finish. It’s a huge subwoofer, and the fine finish does go a long way toward making it palatable, but it can’t hide the sheer size of the unit. The lengthwise edges are rounded, which helps to soften its appearance. As with the PB16-Ultra, the PB17-Ultra has a front-mounted glass fiber laminated cone with a reflective sheen and ‘SVS’ imprinted in the center. Underneath the cone are three flared ports. A grille is provided to cover the front baffle if you want to hide the cone and ports for some reason. The grille is just some black fabric draped over a plastic frame. It does mute the sub’s appearance somewhat, but it also makes the sub look less interesting. Overall, SVS has made the PB17-Ultra about as nice as a large oblong box can be made to look. Some people will object to it based on the size, but if you can get past its size, there is nothing to complain about regarding its styling.

SVS PB17-Ultra R|Evolution Subwoofer Design Analysis

Let’s start our discussion of the PB17-Ultra by talking about its driver. As denoted by the name, the PB17-Ultra uses a 17” driver, but that is only measuring from the outer diameter of the frame edge. The cone itself is not that large. Cone diameters are usually quoted from the middle of the surround, and in this case, the cone diameter is a bit short of 15”. Most subwoofer manufacturers use the frame edge diameter specification in their literature, not the actual cone diameter specification. As with the PB16-Ultra, the PB17-Ultra uses an enormous 8” voice coil, but one difference is that they have split it in two, so the PB17-Ultra now has a dual voice coil system. Two voice coils allow more options in how the driver is powered, and SVS takes advantage of this by using two amplifiers, but they don’t just use each amp to power one coil. Rather, they utilize bridge-tied load (BTL) amplification so that both channels are powering both coils. One amplifier amplifies the positive phase signal, while the other amplifies the negative phase signal, effectively doubling the voltage compared to using just one amplifier channel. BTL amplification can theoretically achieve four times the output power compared to a traditional single-ended configuration.

The coils wrap around the permanent magnet, which is a 54-pound chunk of ferrite, and that should give it a tremendous level of magnetic force. The coil uses an overhung configuration as opposed to the PB16’s underhand configuration, and that should give this new driver more sensitivity in higher frequency bands. Suspension consists of dual Nomex spiders and a half-roll styrene-butadiene rubber surround. A lot of attention had to be given to the suspension components to keep linear movement over a wide throw. SVS claims the PB17-Ultra driver has a 48.9mm Xmax. I find that figure difficult to believe except in certain specific senses such as a Bl measurement, although I have no doubt this driver has a very long linear throw. The driver also uses two shorting rings to help maintain linearity. The basket is a beefy powder-coated cast aluminum structure that should be able to endure high excursions from the moving assembly with ease.

In terms of amplification, SVS has backed the driver up with 2,800 watts of RMS power. The system looks to be designed to pull as much current as can be had from the standard 15-amp circuits of North American homes. SVS uses a class-D amp with a switching-mode power supply — a very efficient design. Efficiency is absolutely needed to convert as much power as possible from a 15-amp circuit into sound for the kind of performance targets that SVS is aiming for. In my review of the PB16-Ultra, I remember that unit being able to dim my lights at high drive levels, effectively maxing out what that 15-amp circuit could deliver. So, in order to get more output, SVS had to look at higher efficiency rather than just brute force power draw, or else they would risk tripping the breakers of typical residential power circuits.

The two mono amplifiers use eight 60A 200V MOSFETS. The amplifiers are arranged in parallel per rail for higher output current. Power draw is constantly monitored in real-time via Power Factor Correction with an onboard line conditioner, thereby allowing the amplifier to draw as much power as it needs without overwhelming a 15-amp circuit. The system is controlled by a 290Hz Analog Devices Audio DSP chip, and that should be more than sufficient for any processing on the signal, as well as monitoring power conditions. Connectivity is comprised of a pair of XLR inputs and outputs and a pair of RCA inputs and outputs. The XLR inputs and outputs are especially nice for those who want to incorporate the PB17-Ultra into more upscale home theaters or even pro-audio setups. The amp panel also has a 3.5mm trigger and a USB power source for easy integration of the SVS Soundpath Wireless Adapter. Basic functions can be operated by a small OLED display on the amp panel with some selector buttons. Advanced functions have to be operated through SVS’s Subwoofer Control Smartphone app.

To me, relegating all but the most basic controls to the app is a problem. So much can go wrong on the software side that I am sure there will be more than a few instances of the sub simply not being operable by some phones. Also, in the long term, what if SVS does not or can not keep the software updated to work in future software environments? In that case, so much of the feature set of the subwoofer would simply be lost. 

We have covered the many features of SVS’s Subwoofer Control app many times before, so we won’t go over all of that again, but rather we will mention a new feature that SVS promises but has not yet released as of the date of this writing: the Subwoofer Auto Room Equalization. Supposedly, this feature will use the Smartphone’s own microphone to take in-room measurements. It is an interesting idea, and I suppose one way to do that is to calibrate the phone with the sub itself in a near-field measurement. That is just a guess, though. We will hopefully evaluate that feature when it is released.

 

The enclosure has a boulder-like solidity (and weight). Side panels look to be about 1” thick, with the front baffle being 2” thick. With an all-MDF construction, that will constitute the bulk of the weight of this 167-pound subwoofer. The interior is lined with acoustic stuffing. There are three ports with a 4” diameter that stretch way back in the sub and take a turn upwards. Such long ports with a 4” diameter promise some seriously deep bass. Like its predecessor, the PB17-Ultra has variable-tuning capability, so one of the ports can be sealed to lower the port tuning frequency and thus the low-frequency extension that the sub is capable of. Additionally, users can seal all of the ports to turn the PB17-Ultra into a sealed subwoofer, but, in my opinion, that would be inane. What is the point of buying a gigantic ported sub just to neutralize port output? The reason this sub is so big is for port output. If you want a sealed subwoofer, get the SB17-Ultra. SVS claims a response window of +/-3dB down to 12Hz when configured for extended mode and 14Hz for standard mode. That has to make this the most deeply tuned mass-produced subwoofer in history. There are other subs that can be bought with extremely deep tuning frequencies, but none that you can just walk into a store and buy. They have to be ordered from smaller manufacturer-direct subwoofer companies, and then there is a wait period for construction and delivery. 

One unfortunate carry-over from the PB16-Ultra is the feet. They were too small for that model, and SVS has opted to use them again in the PB17-Ultra. They do not give your fingers much clearance if the sub has to be lifted and set down, barely half an inch. That can be a problem for a subwoofer of this weight, especially if the sub is being lowered onto dense carpeting. Users should not underestimate the task of lifting or carrying this sub. It’s a two-person job at the very least, and those two people better be in good shape. If being carried over stairs, a dolly is a must, whether a shoulder-strap dolly or a wheeled dolly. Anyone who decides to order the PB17-Ultra would do well to carefully consider the logistics of safely getting it into place.

SVS PB17-Ultra R|Evolution Subwoofer Listening Sessions

The best placement for a single sub in my room gives me a relatively flat response for an un-EQ’d single subwoofer, with a window of +/- 4 dB from 25 Hz to 100 Hz with no broad dips in important ranges. This location trades low-end room gain for a relatively flat response — a worthwhile trade for my tastes. The receiver used was a Marantz AV7705. The crossover was set to 80Hz. The speakers used were some DALI RUBIKORE 8 speakers.

As always, I will note here that since room acoustics have a huge effect on low frequencies, the way these subwoofers sound in my room at my listening position is not necessarily going to be the way they sound 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

“Midnight at Notre-Dame” is a 2004 pipe organ release performed at, you guessed it, the Notre-Dame Cathedral pipe organ. I figured it would be nice to hear from this cathedral now that Notre-Dame has been reopened, although its pipe organ is still being worked on from the 2019 fire. These pieces are played by their resident organist, Oliver Latry, and they are a great exhibition of not only that famed organ’s range but also the skill and artistry of Latry himself. This album has four pieces by Bach, two by Mozart, and a handful by other famous composers. These are some of the more dramatic and lively works that can be played at an organ recital, so they make for a good demonstration for an audio system. The Notre-Dame Cathedral pipe organ is a good one for pushing the limits of subwoofers due to its enormous 32’ pipes capable of 16Hz notes, and this recording doesn’t shy away from the bass power of this mighty instrument. I streamed this album from Qobuz.

Many of these tracks won’t blow the doors down with bass, but low frequencies are a constant presence, and a well-behaved sub is needed to properly integrate the sound to form a seamless whole. It didn’t take the PB17-Ultra much calibration to get to that point, and the organ sounded like a single instrument without any disconnectedness from the bass. Low-frequency drama picks up a bit in the third track, “Adagio and Fugue in C Minor” by Mozart, and the larger pipes of the Notre-Dame Cathedral organ start to assert themselves more. Sustained low notes growled with a mighty pulsation. The album ended with a bang with Bach’s “V. Chaconne” from “Partita for Violin Solo in D Minor.” This transcription for organ, as well as Latry’s playing, loses none of Bach’s dynamism, and while I have great respect for the violin, I think that the original violin version of this composition would be a letdown after hearing this pipe organ performance. In this piece, the PB17-Ultra gave a sense of scale to this monumental instrument. The PB17-Ultra provided the low frequencies with the physical presence that would be had at an actual pipe organ recital. I haven’t had the privilege of hearing the Notre-Dame Cathedral pipe organ in person, but I have to imagine it would sound tremendous. While I doubt any sound system could equal it, I would guess that the PB17-Ultra at least brings some of the low-frequency grandeur of its sound that pipe organ enthusiasts will greatly appreciate.

 

For a taste of what the PB17-Ultra can do with the double bass, one of the few other acoustic instruments that digs into deep bass, I threw on GoGo Penguin’s “A Humdrum Star.” I only recently discovered GoGo Penguin, a Manchester-based jazz trio that merges traditional jazz instruments with electronics, but I have become enamored with their sound. The double bass is featured prominently in their works, and the production has a clean sound that makes it a great showcase for hi-fi systems that have good low-frequency capability. I streamed this 2018 release from Qobuz in 88.2kHz/24-bit resolution.

The first track gets its bass from the piano, not an instrument known for hard-hitting bass, but the lowest note on a full-sized piano does have a fairly low 27.5Hz fundamental. The PB17-Ultra gave some body to the lower piano notes that helped to make it sound like a grand piano was in my living room. The second track really picks up the tempo, and a rapidly plucked double bass gives the PB17-Ultra a chance to shine with quick transients. The subwoofer nailed the sharp attacks of the plucks, and I didn’t get any sense of delay or lag. The kick drum also had fast attacks and decays that the PB17-Ultra gave a good thump to without lingering. Subsequent tracks had the sub lending a meaty sound to the double bass but without any overhang. The double bass fell into some wild rhythms in Track 5, “Strid,” and the PB17-Ultra had no problems tracking these busy melodies. The syncopated rhythms of track 6 also gave the sub a lot to feast on as the percussion and double bass played furiously. The PB17-Ultra proved its musical adeptness in this and other tracks by bringing a physical dimension to the bass without overshadowing higher frequencies or having a sense of detachment. The PB17-Ultra is almost certainly overkill for jazz music recordings, but those who buy it with the intention of listening to jazz need not fear that it’s merely a “home theater” subwoofer; it turns out to be an outstanding subwoofer for acoustic recordings.

For something very different, I threw in a new release from the CryoChamber label titled “Phantasmora” by Cities Last Broadcast. This is a dark ambient album with lots of deep bass content, although it doesn’t tend to crank the bass to thunderous drive levels. This music sounds like a score from a killer horror movie set in the far future. The album is a journey into some dark depths and uses deep bass in a variety of forms to chronicle its descent. The low-frequency use here is carefully leveraged and sculpted, and a subpar subwoofer might either miss the deepest frequencies and/or exaggerate the mid-bass frequencies. Linearity and extension are a must for getting the most out of this album.

The album starts out with a textured rumble underneath some lo-fi chanting. The bass sound had a granular quality that I wasn’t sure was in the low-frequencies or some upper frequency component being played by the speakers, so I turned off the amp powering my left and right fronts to hear what exactly the sub was doing, and in this case it was reproducing a grittiness in the bass that was more than just a vague rumble. The second track brought in a deeper bass that felt like a plunge into the abyss, and the PB17-Ultra gave this sound a cavernous sensation as though the listener had entered an inhumanly large realm. Subsequent tracks used textured deep bass as a means of conveying the fluctuating drone of some kind of gigantic machine, and the PB17-Ultra rendered the irregular texture of the drone with precision. Much of the low-frequency sounds were subtle supports for the atmosphere of the album, such as the type of low-frequency warbling that would be heard on deteriorating analog recordings, and the subwoofer could give these sounds some weight without eclipsing higher frequency content. Again, the PB17-Ultra is certainly much more powerful than anything that this type of music would ask for, but it’s nice knowing that it knows how to use a lighter touch when needed.

  

Deep, Dark, and Dangerous is a New Zealand record label devoted to electronic bass music, and “DDD100” is a celebration of their artists as their 100th release. It’s a full-length double album of tracks that are collaborations between their label regulars, plus a few newer artists. This music is primarily deep dubstep, and as such, the bass is used prodigiously. At high drive levels, this music will place a heavy load on any subwoofer, and that is what I sought to investigate by blasting it on the PB17-Ultra. Will SVS’s newest sub be more than my ears can handle, or will I be able to withstand the best that this sub can dish out? I cranked the volume to find out…

I quickly found out that the PB17-Ultra had more dynamic range than my ears did, so I backed down the system volume out of concern for the welfare of my eardrums. The PB17-Ultra had more than enough power to shake my seat with every wobble of the bass line. Kick drums could easily be felt as punches in my chest, and the tactile abilities of the sub were pretty phenomenal. It also helped me find resonances in my ceiling that I could detect as buzzing sounds that needed sufficient SPLs to induce. Even at extremely high drive levels, I never heard anything resembling distortion or compression. The PB17-Ultra kept its composure no matter how loud I drove it. Some highlights from this album’s 24 tracks include “From Birth” by Abstrakt Sonance for its killer lyrics, “Lana” by Oxossi for its frenetic staccato bassline, and “Heavenward” by Dayzero for its psychedelic lead over a massive bass line. If you are a fan of electronic bass music, the PB17-Ultra is a rock-solid choice. It punches hard at any frequency and doesn’t break a sweat doing so.

Movie Watching

Zach Snyder’s effects-driven films have always been a source of profuse low-frequency use, and the new “Rebel Moon” two-parter series did not look like a departure in that regard. The plot description intrigued me: a mysterious young woman gathers a group of proficient warriors from neighboring planets to help defend her colony from a despotic regent. This reminded me of a favorite of mine, 1954’s “The Seven Samurai,” and although “Rebel Moon” was critically panned, I was eager to see what kind of spin Snyder would put on Kurosawa’s classic. This big-budget Netflix production was sure to have ample use of bass.

“Rebel Moon” certainly did not disappoint in the bass department; in fact, I would say these are some of the top movies in that regard. I watched the ‘director’s cut’ edition of these movies, and by the end of each of the two parts of this movie series, I was pretty drained. Zach Snyder’s movies don’t take too many breaks from pummeling the viewer with spectacle and brutal action. It was made all the more abrasive with such a powerful subwoofer taking care of the low end. The PB17-Ultra was a relentless partner with the movie in delivering an epic experience. Some examples of its low-frequency prowess would be any of the scenes with spaceships because of their guttural and ground-shaking sound effects. The city-destroying cannons mounted on the dreadnought ships were given a subterranean rumble that gave it a frightening reality. In fact, the sights and sounds were so strikingly designed and reproduced that the movies’ bizarre retro-future setting was brought to life despite its sheer fantasy. That is to say, there is an awful lot that didn’t make sense, but it was still easy to let myself suspend disbelief because of how well-realized this world was. The PB17-Ultra helped in this regard by providing a sonic foundation for the movies’ most grandiose scenes. Infrasonic bass was effortlessly produced in massive quantities, as per the films’ sound mixes. I don’t think many subwoofers could have done what the PB17-Ultra managed to do with this movie. I enjoyed the “Rebel Moon” series, but they are movies that are so reliant on aesthetics and sensation that a good A/V system is really needed to get the most out of this viewing experience. Thankfully, I had that on hand with the PB17-Ultra.

  

With the PB17-Ultra in house, I decided to see what all the fuss was about with “Deadpool and Wolverine,” one of 2024’s highest-grossing films, an unusual feat considering its ‘R’ rating, which should have kept away families with children. This one looked quite bombastic on the ears, so this movie should be a good opportunity for the subwoofer to show what it can do with a high-energy film sound mix.

The PB17-Ultra turned out to be a perfect match for such a rambunctious sound mix. Much like the movie, the sound mix was over-the-top, and so bass was used profusely. Much of the deeper bass usage occurred in the slow-motion scenes, and the PB17-Ultra used them as an opportunity to shake an unbraced object in my listening room. Ceiling panels and loosely hung pictures rattled with enthusiasm in my room, and the PB17-Ultra managed to overcome the solutions I had implemented years ago to address those problems. Apparently, those solutions were only effective up to a certain decibel level. The first battle scene of Deadpool fighting the ‘Time Agents’ with Wolverine’s bones had a ton of bass, and every blow was given a visceral wallop that shook my seat. Another bass fest was the fight between the Void's resistance group and the antagonist Cassandra amidst the approaching Alioth monster. My listening room is probably a tad larger than average in cubic feet, but the PB17-Ultra filled it with thunderous low-frequency output. Throughout all the mayhem, I never heard anything that indicated the PB17-Ultra was being stressed, such as port chuffing or distortion. The only sound problems I had were from the sub shaking my room so much. I am not the biggest Marvel fan, but “Deadpool and Wolverine” turned out to be a fun ride, and such a potent sub in the sound system certainly elevated the experience. 

SVS PB17-Ultra R|Evolution Subwoofer Measurements

 

 

Testing on the SVS PB17-Ultra was conducted with the microphone facing the woofer at a 1-meter distance with measurements scaled back to a 2-meter distance by subtracting 6dB. The temperature was recorded at 60°F with 80% humidity. The subwoofer’s gain was set to maximum; the phase was set to zero, and the low-pass filters were set to bypass.

 

The above graph shows the measured frequency responses for the SVS PB17-Ultra subwoofer for standard and extended operating modes. Standard Mode was tested with all ports open, and Extended Mode was tested with one port sealed. As we have seen so often in SVS subs, we get a ruler flat response. This is nice, of course, but readers should understand that room acoustics will mutilate this picture-perfect response once the sub is in place. It’s still worth pursuing a flat response since it makes for more predictable behavior for multi-subwoofer setups. We can see that the Extended Mode digs a bit deeper than Standard Mode and looks to extend the knee of the response about 3Hz deeper. But there are no free lunches in audio engineering, and the catch of that extended response is less port output. By removing one of the three ports, the port output should be similarly reduced by a third. However, this sub is so powerful that it is probably a worthwhile trade-off for most users since they aren’t likely to hit the limits of this beast. 

SVS claimed a response window of +/-3dB of 12Hz to 220Hz in Extended Mode and 14Hz to 220Hz in Standard Mode. That isn’t quite what we see in our measurements. I would characterize what we see as closer to 14Hz to 170Hz in a +/-3dB window for Extended Mode and 16Hz to 160Hz in Standard Mode. That still makes for a very deep-digging subwoofer, and the in-room response will dive down well into infrasonic frequencies. 

 

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 9dB down from the standard requirement for the measurements to be shown at 1-meter peak. However, most publicly available CEA-2010 measurements are shown at 2-meter RMS, so we followed that convention.

The above table of burst measurements is for the PB17-Ultra in Extended Mode. These are some pretty tremendous results. 107dB at 16Hz and 110dB at 20Hz is an earthquake in a box. And an average of 118dB at 31Hz and above is brutal mid-bass power. What is interesting is to see how this sub compares to our results from its predecessor, the PB16-Ultra. While we weren’t able to get a passing result from the PB16-Ultra at 10Hz, we did with the PB17-Ultra. When comparing both subwoofers in standard mode, the PB17-Ultra has nearly a +10dB output advantage at 16Hz, almost +3dB at 80Hz, and +6dB at 100Hz over the PB16-Ultra. This means it’s not only more capable in the infrasonic range but also delivers stronger mid-bass slam too.

 

The above table shows our CEA-2010 burst results for the PB17-Ultra in Standard Mode. Again, we see monster SPLs being produced by the subwoofer across the board. Oddly, the deep bass output of Standard Mode seems to be on the level of Extended Mode. However, Standard Mode isn’t quite as clean in terms of distortion when pushed to the edge in those lowest frequencies, and that is not surprising.

 

Regarding mid-bass output, I was skeptical when SVS claimed they had gained up to 7dB more output in mid-bass versus the PB16-Ultra, but their claim really does pan out in both of the tested operating modes. One of my criticisms of the PB16-Ultra was that its mid-bass output could not keep up with its deep bass output, but SVS has solved that problem entirely. This allows a higher crossover frequency for PB17-Ultra users with the assurance that its mid-bass punch will match its deep bass rumble. Bravo SVS! Either operating mode of the PB17-Ultra earns our Bassaholics ‘Maximus’ Room Rating, meaning it should be able to handle a room of over 6,500 cubic feet. It is only the fourth subwoofer that we have tested that was able to accomplish this feat. To learn more about Audioholics’ Bassaholics Room ratings, please look at this article: Bassaholic Subwoofer Room Size rating Protocol.

 

 

Testing for long-term output compression was done by first conducting a 20-second sweep tone where 50Hz hit 90 dB with the subwoofer 1 meter from the microphone (graph has been scaled to 2 meters for easy comparison with our other review measurements). We then conduct further 20-second sweeps by raising the gain by 5dB until no more output can be wrung out of the subwoofer. These tests show us the long-term continuous headroom that the subwoofer is capable of.

These are terrific results from the PB17-Ultra. It holds its ruler flat response until the last 5dB of headroom, where it starts to compress port-generated output just a bit. This happens in both modes. Not surprisingly, it does have a bit more overall headroom in Standard Mode than Extended Mode, although Extended Mode does have an edge in deep bass below Standard Mode’s port tuning. Both modes are scraping up against 115dB of continuous output. That is some pretty pulverizing bass. 

 

 

The above graph shows the corresponding total harmonic distortion to the long-term output graph. Essentially, it depicts how linear the subwoofer remains for the corresponding drive level seen in the long-term sweeps. The quantity being measured is how much of the subwoofer’s output is distortion, shown here as a percentage.

Again, these graphs are a terrific showing by the PB17-Ultra for both modes. Only in their highest drive levels do they exceed 10% THD above port-generated frequency output. At nominal levels, they offer extremely clean distortion performance, largely hovering under 1% total harmonic distortion above 30Hz. In the ‘3D perspective’ graph view, any black that you see is almost totally clean bass, for all practical purposes. There is a lot of black. We do see some slightly more elevated levels at lower drive levels at deeper frequencies, but much of that is background noise of the testing environment and not from the PB17-Ultra itself. The reality is that the PB17-Ultra performs better than what these graphs show. At the highest drive level, it can be pushed to produce some audible distortion, but I don’t think any users would push it that hard unless they were deliberately trying to hit its limits. It’s difficult for the PB17-Ultra to produce anything other than clean, undistorted bass.

 

 

The above graphs depict measurements of the constituent harmonics from the long-term output sweeps and are what the total harmonic distortion measurements are composed of for the 2nd and 3rd harmonics. These individual harmonics can give us a clue as to what might be the cause of some quirk or non-linearity. We are only showing the 2nd and 3rd here because they more or less reflect the higher even-order and odd-order behaviors, although higher-order harmonics tend to be much farther down as a percentage of distortion compared to the second and third.

There isn’t anything all that unusual about the harmonic composition of the PB17-Ultra’s distortion. One item to note is how the second harmonic spikes just under 50Hz at the highest drive level. I am not sure what to attribute that to, but I don’t regard it as a serious problem. One thing to note is the lack of even-order harmonics at lower levels; to me, that indicates that SVS has managed to keep inductance effects under control, which is surely a challenge with so much voice coil. 

Set Up Tip: Unsurprisingly, Standard Mode fares a bit better with distortion overall, so if you want the cleanest possible bass from your PB17-Ultra, run it in Standard 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 20ms to be completely unnoticeable, but that is likely meant for mid and upper bass frequencies.

The PB17-Ultra puts up a very good showing in this measurement and improves upon its predecessor. Group delay doesn’t cross 20ms until around 30Hz below which human hearing is very insensitive. Above 40Hz, it hovers at or below 10ms. That is very good time domain performance. Many people would assume that a big ported sub wouldn’t be great for crisp transients in music, but that wasn’t my experience with the PB17-Ultra, and that is not what our measurements indicate. The different operating modes do not make a big impact on group delay either. Port-generated output does jump up to a cycle of delay, as would be expected. However, it’s far too low in frequency to affect anyone in musical range or likely anything that human hearing would perceive as amiss.

SVS PB17-Ultra R|Evolution Subwoofer Conclusion

As always, I will briefly go over the strengths and weaknesses of the product under evaluation, and, as usual, I will start with the weaknesses, since I am the kind of guy who wants the bad news first. There is a lot to like about the PB17-Ultra, but it does have a couple of shortcomings to be aware of. One aspect that may be a problem for some potential buyers is its size and weight. It’s huge and very heavy at nearly 170 lbs. Other household occupants might object if you try to integrate it into a typical living room. It has a very substantial footprint. However, anyone looking at this kind of sub to begin with is likely aware of its size and mass and is prepared to deal with that. I would urge all potential buyers to have a plan to deal with the logistics of getting it into their home and its final destination. For many buyers, this will be a serious challenge, especially if they have never owned something like this before. I don’t hold the PB17-Ultra’s size and weight against it, since it can’t have its level of performance or build quality otherwise, but buyers need to be aware of the physical challenges of dealing with such a monster.

Something that complicates the task of dealing with the PB17-Ultra’s mass that I do hold against it is the feet. Again, SVS has opted to use very small and slight feet that do not give the sub much ground clearance. This makes picking it up and setting it down by hand a risky task, because fingers are not allowed much space between the ground and this tremendously heavy object. SVS might tell users to just use furniture sliders, but that isn’t always viable. SVS should have equipped the PB17-Ultra with feet that provide more clearance for fingers. The PB16-Ultra had the same problem, and it’s a shame that SVS didn’t rectify that error here.

Something else I wish were different about the PB17-Ultra is how many functions are relegated to the app. SVS only allows the most basic controls onboard the sub itself. It’s enough to integrate it with any receiver or processor and let those exterior devices take over calibration, but if you want any more control over the sub by itself, outside of volume, phase, and low-pass frequency, you need the app to work. The problem with that should be obvious for anyone who has ever struggled getting an app to work with a phone or tablet. Software environments can have so many variables that if something goes wrong, it can be very difficult to solve. Users will be at the mercy of a software environment that is constantly changing. I am sure that SVS will support the app for a good long while, but what happens fifteen or twenty years from now? No one knows what the future holds, but any access to the PB17-Ultra’s advanced feature set depends on everything going swimmingly for the foreseeable future. Other companies have been able to design ways that advanced DSP feature sets can also be accessed in the sub itself, and I think SVS could have found a way to do that as well if they wanted to.

With my criticisms of the PB17-Ultra out of the way, let’s get into its strengths. Its foremost strength is its immense performance. It can produce an enormous level of output from infrasonic frequencies to any reasonable upper limit that would be crossed over to the main speakers. And it produces all of this output with superb control and linearity. It has a ruler flat response that it holds up to extreme amplitudes, and great time domain performance for quick attacks and decays. It does not sacrifice fidelity for output and could be used just as easily in a two-channel music system as a surround sound home theater system. Its predecessor could produce deep bass at huge SPLS but wasn’t able to hit as hard in mid-bass frequencies. The PB17-Ultra maintains huge SPLs all the way into upper bass ranges. It improves upon the PB16-Ultra in mid-bass output as well as time-domain performance.

Furthermore, SVS didn’t sacrifice build quality to afford these performance gains. It has the same overkill build that the PB16-Ultra did. That is both a good and bad thing: it is built like a tank and therefore weighs as much as one. It certainly achieves the build quality of a luxury product. The PB17-Ultra also looks very nice for a large subwoofer. The gloss black finish and rounded edges go a long way toward making this huge subwoofer look classy. It’s a miracle it can do all of this with only a very mild pricing increase from its predecessor.

While I previously criticized SVS for loading most of its features on the app, I do have to complement it on some of those features because they can be very handy. I especially like the 6-band parametric equalization that can be used to help combat room modes. Its parametric equalizer in combination with XLR inputs makes it an interesting choice for pro-audio systems that don’t typically have automated room-correction systems like Audyssey or Dirac built into studio gear. Parametric equalization also makes it a great choice to fight room modes for simple two-channel systems that do not have sophisticated DSP functions. SVS promises an automated room correction feature in future versions of their app, and that could be exceedingly useful, but it isn’t available yet. We plan to evaluate it when it materializes.

SVS vs the Competition

What subwoofers out there compete with the PB17-Ultra? One sub that we reviewed which competes with the PB17-Ultra head on is Klipsch’s RP-1600SW. It is similar in size and is also capable of a tremendous amount of output. Its advantage is that it costs a thousand less than the PB17-Ultra, but it doesn’t quite match the raw output or extension of the PB17-Ultra. It also lacks the app features of the PB17-Ultra. Another ported giant that we reviewed was the Arendal Sound 1723 Subwoofer 2V. It doesn’t match the PB17-Ultra in terms of output, but it has a smaller footprint, a bit more elegant appearance, and advanced DSP features that do not require an app to access. Monoprice has two subs that compete with the PB17-Ultra: the Monolith 16” THX Ultra and the Monolith M-215. While we have not formally reviewed those subs, we have tested the 16” THX Ultra and have reviewed its little brother, the 13” THX Ultra. The big Monolith subs should have roughly similar performance to the PB17-Ultra and are a bit less expensive, but they do not have anything with a gloss black finish, and they don’t have sophisticated app control. One other sub that competes in this space is the JTR Captivator 2400. We have not formally reviewed this subwoofer, but we have performed acoustic testing on it. It does exceed the raw performance of the PB17-Ultra, however, it does cost $1k more and doesn’t have the extensive feature set or fine finishes of the PB17-Ultra.

When ordering from SVS, buyers get more than just a subwoofer; they get SVS’s renowned customer support along with it. SVS’s warranty stands as one of the best in the business, at 5 years for all components in the unit, including electronics. Buyers get a 45-day trial period in which they can return the sub free of charge for any reason, with SVS paying return shipping. That is extremely generous for the PB17-Ultra, which is surely not cheap to ship. SVS certainly has confidence in its product here.

If you are looking for a single badass sub to power a home theater, the PB17-Ultra can do that. If you are looking for a sub that can complement your high-fidelity music setup, the PB17-Ultra can do that as well. It can even take care of the low-end of a recording studio for those looking for an accurate subwoofer for content creation. The performance lacks nothing. The only question is size and price. The PB17-Ultra is not an inexpensive sub at $3k, but I think it's a great deal when you consider all aspects of the product. The main question is, can you fit this behemoth into your listening room? If so, I wholeheartedly recommend giving it a try; this is a subwoofer that will surely bring smiles to its listeners.

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