Perlisten S4b Brings Flagship Performance Bookshelf Speaker Review

Perlisten S4b Bookshelf Speaker Introduction

Perlisten left a tremendous impression on us when we reviewed their flagship tower S7t speakers earlier this year. It was a speaker that pushed passive loudspeaker technology forward in a big way. It had a huge dynamic range, near-perfect on-axis response, outstanding directivity control, subwoofer-level bass extension, and a cool, futuristic look. One of its only potential problems was that it was a fairly large loudspeaker, and what if you wanted that technology without the size or weight? Enter the Perlisten S4b.

We had seen what Perlisten could do in a large tower speaker, but how well would their technology lend itself to a much smaller form factor? That was the question that prompted me to inquire about the possibility of reviewing a pair of the S4b bookshelf speakers. Sure, it isn’t likely to have the dynamic range of the S7t speakers, nor the subsonic bass extension, but it’s a speaker that doesn’t become a logistical challenge for those who don’t have several able-bodied adults handy if the speakers need to be moved. It also doesn’t have the presence of the S7t for those who don’t want the speakers to be such an imposing visual element of the room. The S7t is a lot of speaker, and there are certainly those out there who are interested in Perlisten’s design technology but don’t need that much speaker. The S4b looks to be an answer to that, but how much of the S7t’s sound is left when it is squeezed into a bookshelf speaker form factor? Let’s take a deep dive to find out…

Appearance

Stylistically, the S4b speakers remain the same as the S7ts. It has the same characteristic checkered woofer, the same waveguide, same grilles, and the same rounded front baffle design. I described the appearance of many of these same components in detail in my review of the S7t, so I won’t repeat all of that here, suffice it to say that the S4b speakers look like an excised mid-section of the S7ts. That's not a bad thing since the S7ts looked so cool. The pair that I was sent had a gloss black cabinet, but it also comes in gloss white or a few different real wood veneers such as ebony or cherry. The wood veneers can be had in either a gloss or matte finish.

Perlisten also sent me their bookshelf speaker stands for the speakers, and these have to be the nicest looking stands I have seen to date. They have a steel floor base that has a curved cutout to wrap around the feet. The feet are the same seen on the S7ts: some round metal pieces that have some polished brass rings as well as polished brass spike tips. The top platform is held up by a gloss,-rounded metal support column. These speaker stands are a great aesthetic match for the S4b speakers and would flatter any other speaker that you could use them with.

The S4b speakers are high-end bookshelf speakers and look the role, especially with Perlisten’s speaker stands. As with the S7ts, I felt that the grilles did not improve their appearance, so unless there are rowdy children or pets afoot, I would keep the grilles off.

Design Analysis

The Perlisten S4b retains much of the same technology and components as the S7t speakers, merely deployed on a smaller scale. This being the case, we will be quoting ourselves a fair amount from relevant portions of the S7t review to describe design elements of the S4b. We will start our discussion of the S4b with one of the most distinguishing design elements of the Perlisten speakers, the DPC waveguide. As the name suggests, the DPC waveguide is used to control vertical dispersion, but it does so in a much more sophisticated manner than traditional waveguides. In addition to just using a physical boundary to compress pressure waves into a specific dispersion profile, the DPC waveguide uses transducers to help guide sound waves by way of beamforming. Beamforming occurs when multiple drivers transmit the same signal in a way such that constructive interference strengthens the signal and certain angles and destructive interference negates the signal at other angles.

How does Perlisten accomplish this? To quote from our prior review:

...the drivers form an array where they largely work with each other rather than in their own separate frequency bands, so there is a lot of overlapping bandwidths in the crossover filters. This is done to create an acoustic beamforming effect where all the drivers sum up on an intended listening angle and subtract elsewhere. In order to accomplish this, the drivers in the array do not operate at the same amplitude levels or even the same phase angle. In fact, to make the beamforming work, the spacing of the drivers must be precise, both in height and width, and also in depth, and this is why the midrange drivers are mounted ahead of the tweeter in spatial positioning. The advantage of this beamforming is a whole lot of output delivery to a specific direction without needing to throw sound everywhere at a high level.

The restricting of vertical dispersion offers another advantage in that there are fewer floor and ceiling acoustic reflections to contend with, and some research has suggested that this can help make the speaker’s lateral positions less localizable.

The tweeter/midrange section of the S4b that forms the DPC Waveguide is exactly the same as in the S7t. Quoting from our original description:

The tweeter is a 1.1” beryllium dome which produces a strong response well above the range of human hearing. Beryllium is the best tweeter diaphragm that can be deployed on cones or domes on account of its extreme rigidity combined with its very low weight. It’s not used a whole lot since it’s so expensive, but Perlisten wanted to make the best possible speaker in the S7ts, so a beryllium tweeter wasn’t something they could compromise on. A well-made beryllium tweeter will hold its shape out to frequencies far exceeding human hearing, and that means it will have a smooth, well-controlled behavior for any sound that even the finest human hearing can discern. This beryllium dome is propelled by a very powerful magnet in the motor that is far more powerful than what is found in conventional tweeters.

The midrange drivers are two 1.1” domes that use Textreme’s thin-ply carbon diaphragms (hereafter called TPCD). The bass drivers also use this TPCD material as well. These are very light but exceptionally rigid materials that are superb for loudspeaker cones or domes. TPCD is a broad weave of carbon fibers that has the strength of metal diaphragms but not the total material uniformity at every point in the construction. This is an advantage in that it doesn’t bend as sharply at higher frequencies. At a high enough frequency, all loudspeaker diaphragms will start to bend and flex since the force driving the motion isn’t uniformly applied at all points of the diaphragm. This behavior is called ‘break-up,’ and it results in a very erratic frequency response that can sound harsh. So a key challenge for driver engineers is to move those break-up modes into as high frequencies as possible where they can be more easily filtered out. Driver engineers are always on the lookout for a material that can hold its shape for as wide of a frequency band as possible. The TDCP drivers do this well. To be sure, they do run into break-up modes, also called ‘ringing,’ but the modes are heavily mitigated thanks to the structure of the diaphragm, and so the severity of the break-up modes are greatly reduced resulting in higher performance for a wider range of frequencies.

The S4b speakers only have one bass driver, so it isn’t able to extend the beamforming array below the frequency band of the midrange drivers. The bass driver is the same as the S7t, so the same Textreme TDCP cone and same monster motor section. It is a very powerful driver and also a very linear one. The engineering of the bass driver is packed with high-performance elements that we go into with plenty of depth in the S7t review, so those who want the gory details should refer to that article. The woofer takes the range up to about 1kHz, and the three 1.1” domes take over above that point. The Textreme midrange drivers play up to 4kHz while the Beryllium tweeter plays well into ultrasonic frequency ranges, so the midrange domes do have an overlapping band with the tweeter- one of the key ingredients in creating the beamforming dispersion pattern as well as having a wider dynamic range than normal.

THX gives the S4b ‘Dominus’ certification but for a ‘Surround’ role. Unfortunately, THX does not make their certifications clear for the specific role that a loudspeaker plays within the system on their own website. The S4b speakers are not ‘Dominus’ certified for front LCR speakers. Still, they need to be fairly powerful to serve as surround speakers for a Dominus rating which indicates they can handle surround channels roles in a 6,500 cubic foot room. The demands may not be as strenuous as for the front LCR speakers, but it is still significant and far more stringent than what many bookshelf speakers can bear. Given the sealed design of the S4bs, they are expected to be mated with a subwoofer. They are not intended to be run as full-range speakers. Some might complain that such expensive speakers should have some deep bass extension, but to do that would give up dynamic range, and wouldn't be a worthwhile trade-off for the intended roles of these speakers. It would also likely disqualify them for certification for a Dominus system. Besides that, anyone who can afford these speakers can also afford a decent subwoofer and Perlisten makes ridiculously "decent" subwoofers too. 

The cabinet is very heavily built and comprises the bulk of the 24 lbs. weight. The side panels and bracing are made from 1” thick HDF, and the front driver mounting piece is a curved 2” piece carved out of an HDF block and mated with the main enclosure for an incredible 3” thick front baffle. The enclosure is crammed with polyfill, and there is a rubbery damping layer lining the side panels. A widowpane brace adds rigidity to the cabinet’s vertical midsection. This caliber of construction should add up to an extraordinarily inert cabinet. The included grilles might not be the prettiest I've seen, but they do a very good job of protecting the drivers. The grilles are made from perforated aluminum and held in place by some fairly grippy magnets. They should be able to withstand domestic projectiles as well as curious children’s fingers.

There are four screw holes in the back as well as the bottom of the cabinet so they can be firmly affixed by a wall mount on either side. Since the speakers weigh quite a bit, any wall mount that would hold them needs to be very heavy duty and capable of supporting 25 lbs. Perlisten does sell a tilt/swivel bracket that mates with the screw hole pattern on the back for $99 each. Given the vertical dispersion pattern these speakers will have, they would also need to be angled to face the listening position. The terminal plate and binding posts are the same heavy-duty polished brass pieces that were used in the S7ts. They do allow for the option of bi-wiring/bi-amping, but those configurations aren’t as useful on the S4bs as they would be on the S7t speakers. The S7t bass section could take way more power, and it makes sense for bi-amping them if you have an extra amp, but a more down-to-earth amplifier should be enough to fulfill the S4b’s output potential. I think a single set of binding posts would have been sufficient for the S4bs. However, the additional binding posts do not add much more expense, so it’s not a big deal. 

The aforementioned Perlisten speaker stands that can be purchased with the S4b speakers are of formidable construction in themselves. They weigh at least as much as the speaker, if not more. They have matching mounting screw holes to the bottom of the S4b speakers, so the S4bs can be held in place by some included heavy-duty machine screws. The stands are very bottom-heavy, so they would not be easy to knock over. And, if the S4bs are screwed in place, they would have an extremely stable platform. The stands have a 20” height that elevates the tweeter to about 32” which should be roughly level with most ear-level listening positions.

All of this sophisticated design should add up to a bookshelf speaker with an above-average dynamic range with a neutral response- both on and off-axis, as well as a resonance-free cabinet. As with the Perlisten S7t speakers, they should have a fairly controlled vertical response, although not to as low frequencies. It’s a recipe for a good speaker, but let’s see how it sounds in practice…

Listening Sessions

In my 24’ by 13’ (approximately) listening room, I set up the speakers with a few feet of stand-off distances between the back wall and sidewall and equal distance between speakers and listening position. I angled the speakers to face the listening position. The listening distance from the speakers was about 9 feet. Amplification was handled by a Pioneer SC-55. No room correction equalization was used. Subwoofers were used with an 80Hz crossover frequency.

Music Listening

It may be thought of as stuffy and high-brow music, but opera is a terrific genre for exhibiting a sound system’s capabilities in tonality and imaging. One terrific new opera that I found was a performance of a reconstruction of “Argippo” by Vivaldi. Antonio Vivaldi’s version of “Argippo,” which was produced in 1730, has been lost in time in its original form. However, pieces of it survive in what is called pasticcios, musical works that are comprised of different works of other composers, sometimes unauthorized, to form a new opera. Through painstaking research, Vivaldi’s original version has been reconstructed based on the best available materials and is performed here by the Italian period-instrument baroque orchestra Europa Galante along with a bevy of distinguished opera singers. This 2020 release on the Naive Classique label can be streamed from Qobuz in a hi-res 24-bit/88.2kHz sampling rate and boasts a very high level of recording and production quality.

I started listening at a moderate level, and everything sounded so clear and lucid that I decided to crank the volume to a relatively loud level to see if that clarity could be retained. The S4bs relished the high playback levels, not to say they sounded at all lacking at lower levels. The vocal solos soared on these speakers; they sounded sonorous and crisp but without any piercing harshness. This recording on these speakers put me in close proximity to the performance, which is how I imagine it was recorded. Imaging placed the singers at precise positions within the soundstage as well as the instrumentalists. Some recordings in symphonic halls tend to image the orchestra as a blended group as if the listener was seated further back so that individual instrumental positions aren’t really discernable, and the intent is to emphasize the performance as a group. but this recording gives the listener a front-row seat where all the details can be heard, and that intent comes through with fine distinction on the S4b speakers. The overall reproduction was lifelike and didn’t seem compromised at all, despite being replayed through fairly normal-sized bookshelf speakers. The tonal balance and precise imaging combined with the wide dynamic range made for spectacular realism. The S4bs brought this opera into my family room with a nearly tangible verisimilitude, and anyone looking for bookshelf speakers for highly dynamic classical or operatic recordings has a rock-solid option in these speakers.

For something that focuses more on a select group of instruments, I found a high-quality recording in “Silver Lining Suite” by acclaimed pianist and composer Hiromi Uehara. This recent release came about as Hiromi’s emotional reaction to COVID-19’s devastation on the music scene, particularly in the realm of live music performances. While Hiromi is mostly known as a jazz pianist, many of the compositions on “Silver Lining Suite” depart from modern jazz toward classical jazz reminiscent of George Gershwin. She is joined by a string quartet featuring a violinist, a violist, and a cellist, as well as other guest instrumentalists on several other tracks. The musical artistry on display here is first-rate, as are the technical aspects of production from the Concord Jazz label. This album can be streamed from Qobuz in a 24-bit/192kHz resolution and would be an exemplary album for hi-fi demos.  

One aspect of the recording that was easy to perceive right away was how the instruments were recorded. Everything was close mic’d thereby giving the listener the sense that they were sitting among the performers. The piano spread across the soundstage with higher-pitched keys shifted toward the right side much like what would be heard if seated at a piano, and the string players were mixed in for their own positions to the sides of the piano. The S4bs made the sound engineer’s intent vividly clear, and the imaging had pinpoint precision. As anyone who plays piano or who attends piano concerts can attest, pianos can have a very wide dynamic range, and on this 24-bit recording, none of that was lost on the S4b speakers. Indeed many of the key strikes popped with a visceral impact. The timbre of the piano and stringed instruments sounded natural and faithful to the real thing. This recording was reproduced with verve on the S4b speakers, which put the players in my room as though it were a personal concert played for me alone. Seeing as how the genesis of this album was a response to the isolation brought about by COVID-19, perhaps that is the most appropriate effect that it should have.   

For something that emphasizes a solitary human voice, I found a new album by Arooj Aftab, a Pakistani-American musician/singer who is heavily inspired by Sufi music. Her 2021 release, “Vulture Prince,” has a serene and calm instrumental backup for her singing in her mellow, lower-pitched voice. This album’s simplicity serves as a microscope for her voice since there is not much studio processing on it nor is there much instrumental busyness to interfere with the pristine vocal recording.

From the start, this album sounded lovely, and there were many details and soundstage cues that the S4b speakers caught that I had missed when listening to “Vulture Prince” on my desktop PC system. The detail of sound was comparable to a headphone experience, yet the soundstage was exquisitely rendered, which is not something headphones are capable of. Arooj’s voice was anchored dead center in the soundstage with instruments given a broader staging with a touch of reverb. Arooj was abetted by piano, harp, violins, and a subtle french horn, although she is always front and center, and rightfully so. On the S4bs, the instruments had a layered depth with piano and harp in the front and bowed strings and brass in the distant rear. I can’t imagine a finer presentation of this album than what was given by the S4b speakers, and anyone seeking an utterly unclouded reproduction of well-recorded vocals or instrumentals need look no further if these speakers are within their budget.

To see how the S4b speakers would perform on something in terms of dynamics, I loaded up an album by Chee entitled “Eddy Morphine.” The 2017 dubstep release uses all kinds of inventive lead electronic sounds demands to be played loudly. It is not a quiet album nor is it maximally compressed at all times like some pop music can be. At a high listening level, this album can answer the question of whether the speaker can hold up to party levels.

Only moments into the album, I realized that these speakers could rock to a degree that belies their size. They could get truly loud seemingly without any constrictions. The S4b’s dynamics reminded me of large floor-standing speakers. The caveat here is that they are not attempting deep bass at all, so all the bass was supplied by a capable sub- and they would need a capable sub indeed that could keep up with their dynamic range. The snares and claps could hit so hard that they induced an involuntary wince. Lead synths cut through the air with a near corporeal quality (the synths on track 5, “Pedigrief,” sounded as thick as molasses). While I wouldn’t task these speakers with filling a club, at my listening distance, they could produce club-like SPLs without trouble. Not a hint of compression or distortion could be heard, and it may be that my 140-watt/channel amplifier wouldn’t be enough to push them close to any breaking point. It was enough to push my ears to the breaking point, however, and I backed down on the volume to give my ears a break. If you can supply a good sub or two, listening to “Eddy Morphine” at such a high volume left no doubt that the S4b speakers can satisfy anyone looking for serious dynamics from a normal-sized bookshelf speaker.

Movie Watching

One movie I watched using the S4b speakers was “The Dead Center,” a 2018 horror film about a psychiatrist who has an amnesiac patient who insists that he has come back from the afterlife with something nasty. With a premise like that along with many positive reviews, I couldn’t resist it. While this reality-bending nightmare is not a mega-budget Hollywood studio film, it is not a micro-budget indie either and has good production values along with expert sound engineering. It seemed like it would be a good test of traditional movie sound mixes with an emphasis on music and effects sounds that are so critical to a successful horror film.

This movie turned out to be a ‘slow burner’ that makes its supernatural premise seem plausible with very realistic settings, characters, cinematography, and sound design. The sound mix was very intricate at times, with simultaneous elements of patients’ raving, medical staff discussion, environmental noise, as well as less diegetic sounds used to indicate a character’s state of mind. The S4b speakers were able to keep everything coherent and unambiguous. Dialogue intelligibility was never a problem. The speakers were also able to startle with bursts of violence such as the scenes with the “attacks.” Jordan Lehning’s pulsating music score was given an appropriate menace by the speakers and subwoofer. “The Dead Center” turned out to be a terrifically unsettling film that pays to be viewed with a proper sound system, and the S4b speakers more than qualify for executing this unnerving sound mix properly. Highly recommended!

For a sense of larger-scale cinematic sound mixes, I watched “The Outpost,” a Netflix film about the Battle of Kamdesh, which is based on a true account where a small unit of American soldiers in a remote Afghanistan outpost are besieged by far larger Taliban force. I couldn’t say how much this film depiction resembles the events it is based on, but war movies are always a great opportunity for exposing the dynamic range capabilities of a sound system. With the volume cranked high, I set out to see what the S4bs could do in reproducing the sounds of modern battle. The sound of modern war was relayed by the S4b speakers with bombast, and yet again surprised me by how such a modestly sized package could deliver such a big sound. Small arms fire snapped like a fireworks show, and the larger weapons such as mortars and RPGs had a concussive thundercrack that delivered a tangible blastwave that could be felt as well as heard. The S4b speakers gave “The Outpost” a big-screen sound that one would have expected from a commercial cinema. Despite all of the aural pandemonium of battle, dialogue intelligibility was never a problem. The rich profanity of army life was clearly imparted by the S4b speakers, and every F-bomb was splendidly audible. In the end, I enjoyed “The Outpost,” and it deserves the presentation of clarity and wide dynamics that the S4bs were capable of.

Perlisten S4b Bookshelf Speaker Measurements & Conclusion

The Perlisten S4b speakers were measured in free-air at a height of 7.5 feet at a 1-meter distance from the microphone, and the measurements were gated at an 11-millisecond delay. In this time window, some resolution is lost below 250 Hz and accuracy is completely lost below 110 Hz. Measurements have been smoothed at a 1/24 octave resolution.

The above graph shows the direct-axis frequency response and other curves that describe the speakers’ amplitude response in a number of ways. For more information about the meaning of these curves, please refer to our article Understanding Loudspeaker Measurements Part 1. As we have come to expect from Perlisten, the S4b speakers boast a magnificently neutral response. There is hardly anything else to say; this is an accurate loudspeaker. All of the ‘flaws,’ such as the slight dip at 600Hz and the tapered treble above 17kHz, are well below audibility. The smoothness of the early reflections curve and the directivity indexes indicate that this speaker has a high correlation of the off-axis responses to the on-axis and listening window curves, so the S4bs can be equalized with very predictable audible results. They should have the same tonal balance over a wide area in front of them. What is more, with such ideal off-axis behavior, these speakers won’t require much in the way of acoustic treatments for a great sound.

The above graphs depict the S4b’s lateral responses out to 90 degrees in five-degree increments. More information about how to interpret these graphs can be read in this article: Understanding Loudspeaker Review Measurements Part II. Here we get a more in-depth look at the S4b’s terrific off-axis response. Many of these curves maintain a smooth shape out to the “listening window” of a +/-30-degree angle from the on-axis response. The response does fall off a bit after that, at least above 2kHz, but the tight amplitude grouping within that angle ensures a very accurate sound over a good-sized area. Here we also get another look at how tightly these responses hug the 90dB line. That is a beautifully flat response family.

The above polar map graphs show the same information that the preceding graphs do but depict it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, these polar maps use color to portray amplitude and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s behavior more easily. For more information about the meaning of these graphs, we again refer the reader to Understanding Loudspeaker Review Measurements Part II.

In these graphs, we get a better look at the width of the S4b’s horizontal dispersion. I have included the 180-degree graph so we can better see how the midrange dispersion relates to the treble range. As we saw in the previous graphs, the strongest and most even response occurs from the on-axis angle out to 30-degrees. Within that angle, you will be met with an accurate, neutral sound. The dispersion does tighten up a bit above 2kHz, but directivity control is still quite good overall. You do not need the S4b’s to be aiming right at you for an optimal sound, and they have quite a bit more flexibility than that for placement, at least on the horizontal axis. There is a lot of room to play for toe-in angles.

The above graph shows the S4b’s speaker’s response behavior along its vertical axis where zero degrees is directly in front of the tweeter, negative degree values are below the tweeter, and positive degree values are above the tweeter.  It should be said here that the vertical response isn’t as critical as the horizontal response, so an imperfect vertical dispersion is much less of a problem. We can see here that there is a good amount of symmetry between the upper and lower angles of this speaker, thanks primarily to the beamforming array. To get a better understanding of how it works, let’s take a look at it in a polar map view…

Here we can see how constricting the beamforming array is on the midrange/tweeter band. It doesn’t extend to the woofer’s band of 1kHz and below since there is only one woofer which is not enough to form an array. The Perlisten S7t tower speakers used their four bass drivers down to 300Hz. Nonetheless, this tight beam of vertical dispersion is much better controlled than pretty much any other bookshelf speaker in this class. The best sound coverage occurs at +/-15-degrees, so if these speakers are placed anywhere near ear height, you will be met with a smooth response. With so little output at far off-axis vertical angles, acoustic treatments aren’t all that beneficial for these speakers, so don’t worry about using a heavy rug or ceiling diffusers for bettering the sound; the S4bs don’t need that. The symmetry of the response from the upper angle to the lower angle is remarkably, again better than most loudspeakers in this class. There is only one small asymmetry of note in the upper angle of around 30 to 40-degrees at 1kHz that is a crossover cancellation. It is a very mild null for crossover cancellation which is evidence of a highly optimized crossover circuit with steep filter slopes.

The above graphs show the S4b speaker’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide-open area). Here we see an extremely flat response that tapers off to a textbook sealed roll-off slope. If used in a small room or near a surface, the low-end will get a boost, so users can probably expect to get usable bass well below 80Hz. However, these speakers were made to be used with subwoofers and will likely see an 80Hz crossover frequency in most cases. An advantage of the sealed design is that there are no port-related phase rotations that complicate the integration of a subwoofer nor are there any port-resonances that bleed into the lower midrange that can often be seen. The S4b could have been a ported design with more lower bass output, but it would likely have needed a larger cabinet for that (i.e., more difficult to mount and more expensive), and it wouldn’t have done much good anyway since these are likely to end up in systems with subwoofers. Going sealed was the right call for this speaker.

The above graphs show the electrical behavior of the S4b speakers. This is a fairly easy load that is not especially taxing anywhere. Perlisten rates the S4bs as 4-ohm nominal which is about right but it should not present any difficulty to all but the cheapest amplifiers. We can see here that the resonant frequency of the bass driver in this enclosure lies just below 50Hz. I measured the sensitivity of the S4b as 86.5dB for 2.83v at 1 meter. This is slightly higher than Perlisten’s sensitivity spec of 85.4dB for 2.83v at 1 meter. That is about what should be expected given the size and design of this speaker. It is not especially high not is it especially low but rather fairly normal. The S4b’s can get loud, but they do need some wattage to get there. I would look to be powering these with at least 100-watts or so to exploit their dynamic capabilities.

Conclusion

Before bringing this review to a close, let’s quickly go over the strengths and weaknesses of the product under review, and, as usual, we will start with the weaknesses. The problem with discussing the weaknesses of the Perlisten S4b is that there aren’t really any significant weaknesses. It does everything well, and the one area that anyone might criticize it for, low-frequency extension, was a matter of a very logical trade-off. Anyone dropping $8K for a pair of bookshelf speakers has a right not to receive speakers with any significant deficiencies, and with the S4bs, that is what they get. They have to be some of the best bookshelf speakers in their price range. If I had to stretch to criticize them for something, I would say that Perlsiten might have tried for a more attractive grille solution. That is just a nit-pick though, since the S4b grilles, unlike many other speaker grilles, do a good job in protecting the transducer diaphragms. 

Now let’s talk about their strengths. As with their bigger floor-standing brothers, the S4bs have a much wider dynamic range than almost any bookshelf speaker in their size class. If you have the power on tap, they can deliver dynamics that one might expect from tower speakers rather than bookshelf speakers. They also have a unique control over their vertical dispersion that can’t really be had by any other bookshelf speaker in its size and pricing. If you don’t want to have to worry about how your bookshelf speakers will react to floor and ceiling reflections, there aren’t any other bookshelf speakers in their class that can do what the S4bs can. As was previously mentioned, less vertical reflections might have soundstage benefits, and the S4b speakers served up a superlative soundstage indeed. Their frequency response is tremendously flat, and that, in addition to their controlled off-axis response, makes them a very tonally balanced and accurate speaker. They have a flatter frequency response than most studio monitors that I have measured, indeed, they could be used to mix and master sound in a studio capacity without any problems. If you are looking for a high-performing passive studio monitor, they are a great choice. They reproduce the incoming signal with little very coloration, in other words, they reveal the truth of the recording. Wide dynamic range, neutral response, and superb directivity control all add up to outstanding sound quality. 

In addition to the sound quality, the build quality is excellent- as it should be for the pricing. The S4bs have an exceptional solidity, and the “knock test” of rapping on the cabinet with knuckles is like tapping a boulder. It is a luxury item and has the appropriate feel of one. Along with the build quality is the styling; the S4bs look cool. Some people might be divided over their non-traditional drivers and layout, but it looks upscale and high-tech but without being overly stylized. As was mentioned before, the grilles don’t help their appearance, but I think nine times out of ten, they will be used without grilles. They are pricey, but they do look the role. 

At the beginning of this review, we asked whether the S4b speakers could deliver Perlisten’s signature technologies in a speaker of a much smaller form factor than their S7t flagship towers, and the answer is yes! The S4bs do not have the extension or dynamic range of the towers, but they are the “S7ts” among bookshelf speakers. What the S7ts do so well in their class of loudspeaker, the S4bs also do in theirs. The shame of it is that the S4b speakers will probably very often be used as a surround speaker in a Perlisten S-series system. If you ask me, that is a bit of a waste, and these speakers deserve better. Not much is ever asked of surround channels, and not much attention is ever given to surround channel sound, regardless of many popular claims to the contrary. To be honest, you could use a much lesser speaker in a surround channel role, and most people would never notice. But, if you want an absolutely premium, perfectly matched speakers with no compromises, they are what should be used in a Perlisten S-series system. However, if you want a first-class system that is based around stand-mount front left/right speakers, these can foot that bill with aplomb. Highly Recommended!

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
Build Quality
Appearance
Treble Extension
Treble Smoothness
Midrange Accuracy
Bass Extension
Bass Accuracy
Imaging
Dynamic Range
Fit and Finish
Performance
Value