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Perlisten S7t Tower Loudspeaker Measurements and Conclusion

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S7t horizontal response testing 

The Perlisten S7t speakers were measured in free-air at a height of 11’ 2” at a 2-meter distance from the microphone, and the measurements were gated at a 11-millisecond delay. In this time window, some resolution is lost below 200Hz, and accuracy is completely lost below 100Hz. Measurements have been smoothed at a 1/24 octave resolution.

S7t spin graph

I have never seen such tightly controlled dispersion into mid-range frequencies or especially bass frequencies.

The above graph shows the direct-axis frequency response and other curves that describe the speaker’s 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. The Perlisten S7t puts up an excellent showing in every curve here. This graph tells us that it is a superbly neutral loudspeaker on and off-axis. The most significant on-axis deviation from neutrality is a 1dB bump at around 11kHz, and that wouldn’t be audible at all. This is a response so flat that these speakers could easily be used to create sound mixes as well as simply listening to them; the output will reflect the input, so they don’t lie to you or make the content seem better or worse than it really is. One aspect to note is the terrifically flat First Reflections Directivity Index curve, and that indicates that the entire front hemisphere of sound that is projected by the S7t speakers has excellent correspondence to the sound projected within the listening window. That means that any acoustic reflection will not depart from the direct sound for any realistic listening position and also that this speaker can be very predictably equalized.  

S7t waterfall response 3D  S7t waterfall response 2D

The above graphs depict the S7t’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. In these graphs, we get a closer look at what exactly is occurring at off-axis angles. What we have here is another look at the sublimely neutral response of the S7t. The directivity does narrow a bit above 2kHz. That happens too far off-axis to affect the direct response of any listener, however, the acoustic reflections from that angle may put more of an emphasis on the range below that point. The effect might result in giving the speakers a slightly warm touch in more acoustically lively rooms since frequencies above that point won’t be as energetic in acoustic reflections. The effect, if audible at all, would be very mild. There are some high Q peaks and dips occurring well off-axis around 9kHz and above, but they are far too narrow to be audible and shouldn’t be of any concern. There is not much else to note from these graphs except to reiterate just how exceptional the performance is overall.

S7t polar map horizontal

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 the polar map of the S7t, we get a better look at the dispersion and the consequence of the narrowing of directivity above 2kHz. For a full sound, listeners should be seated within a +/-40-degrees of the on-axis angle. That is almost certainly going to be the case in any normal listening situation. One feature to note is that there is hardly any beaming in high treble frequencies. Most speakers see a narrowing of directivity in the top end of the response as it approaches 20kHz. It’s not common for a speaker to have such a wide dispersion at such a high frequency, at least outside of ribbon tweeters and certain waveguide designs. With the S7t speakers, listeners seated as far off-axis as 40-degrees will still be met with an even response out to 20kHz. 

S7t waterfall vertical response

The above graph shows the S7t’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. This is a very interesting look at the beam-formed dispersion of the S7t, and I haven’t quite seen anything like it before. The off-axis response still has some acoustic energy in some very narrow lobing striations, but the main ‘beam’ of sound has a considerably higher level of energy. Let’s take a look at it in a polar map to get a different view of what is occurring…

S7t polar map vertical 

In our polar map view of the vertical dispersion of the S7t speakers, we get a better look at how effective Perlisten’s beam-forming technique really is. And it is truly impressive. Outside of a +/-15-degree angle, output drops off dramatically. That angle should be more than sufficient to encompass all listeners on the vertical axis, even ones seated on an elevated platform in a large room. There are some slight off-axis lobes here and there, but they are too low in energy to matter. The most significant aspect of this graph is how well controlled the beam is over such a large bandwidth. I have seen narrow vertical directivity in tweeter bands in speakers that have tall diaphragms such as ribbons and AMTs or tweeters that had vertical restriction from a waveguide, but I have never seen such tightly controlled dispersion into mid-range frequencies or especially bass frequencies. The beam does begin to widen below 300Hz, and at that point it doesn’t matter as much anymore since that range lays below the transition frequencies of most domestic rooms; in other words, the room’s acoustics will be the primary determinant of the response in that range. Perlisten’s DPC beam-forming technology is putting in some real work here, and the results are amazing. This is the best vertical directivity control I have ever seen. 

S7t low frequency response

The above graphs show the S7t’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide-open area). We can see that the response gently tapers off a bit below 100Hz, and this is a very common design; in fact, it’s what we see in nearly every tower speaker I have reviewed. The reason is that domestic rooms will always give a boost to low frequencies whether through boundary gain or pressure vessel gain and usually a combination of the two. So, a loudspeaker with a flat response down to deep bass will end up having bloated bass in practice. This tapered response is always a sensible design decision for tower speakers because it will yield a more neutral bass response in-room. Looking closely, we see what appears to be a first-order slope down to port tuning around 20Hz, and below that we fall off the cliff much more rapidly with the expected fourth-order slope.

S7t impedance

The above graphs show the electrical behavior of the S7t speakers. Much of the response rides around the 5-ohm mark. Perlisten characterizes the S7ts as a 4-ohm nominal speaker, and that is correct. The phase angles are not especially steep at any of the impedance dips, so there is nothing to worry about here. It might be a hefty load for a very cheap amplifier, but even a mid- to high-end AVR could drive the S7ts just fine - although I would encourage beefier amplification than that to exploit their tremendous dynamic range capability. The low-frequency saddle minima indicates that port tuning is in the mid 20s Hertz range (Perlisten tells me that the port tuning frequency is 25Hz). The lower frequency peak in the low-frequency saddle is much lower than the upper frequency peak, and that tells us that the enclosure tuning is much deeper than the resonant frequency of the drivers, not surprising given a 25hz port tuning versus 7” bass drivers. The overall take-away here is that this is a reassuringly normal electrical load given the exotic crossover circuit and driver topology.

Non-linear distortion for the S7t is spectacularly low. 

I didn’t get a chance to measure the sensitivity of the S7t speakers, but I find Perlisten’s spec of 92dB at 2.83v at 1m to be very plausible given the driver layout and sheer size of the cabinet. What is more is that 92db sensitivity is mandated by THX for a Dominus rating, so THX vouches for Perlisten’s sensitivity spec. 92dB is certainly above average, and that means these speakers don’t need a monster amp to play loud, but their maximum recommended power handling spec of 600 watts RMS does tell us that they can take advantage of a monster amp if you have one handy. 

S7t distortion

...that vertical directivity control is a work of art in loudspeaker design.

The above graph depicts harmonic distortion quantities of the S7t for a 95dB output level at 2 meters using a swept sine wave tone. I don’t normally measure this since I typically do outdoor testing which has too high of a noise floor for accurate results. However, I was fortunate to be testing the S7t speakers in an indoor facility with a low noise floor, and that made distortion testing possible. This test was conducted at a relatively loud level, yet the S7t’s distortion remains extremely low, hovering around 45 to 50dB below the fundamental. The measured distortion below about 150Hz should be ignored in this graph. While distortion would most likely see a rise in that region, the acoustics of the room alter the true performance of the S7t in that range which would artificially suppress true speaker distortion in some frequencies and amplify it in others. The 2nd harmonic does rise a bit where the midrange domes roll off. The tweeter is on its own for playback around 4kHz, but distortion is still very low; at its highest point, it is still 40dB below the fundamental which is 0.5% THD. Nothing shown here is likely to be remotely audible. Non-linear distortion for the S7t is spectacularly low.  

S7t polar map horizontal 180 degrees  S7t polar map vertical 180 degrees

The above two graphs are more polar maps of the horizontal and vertical dispersion of the S7t, but these exhibit the full circumference of the speaker’s acoustic radiation unlike the previous polar maps which only showed the front semicircle radiation pattern. I am showing these so that the reader has a better point of comparison with Perlisten’s own polar maps that are shown on their product spec sheet, which displays the full 180-degrees. I am also showing these so that the reader can get a wider view of the directivity control at work here. Again, that vertical directivity control is a work of art in loudspeaker design. 

Conclusion

S7t pair21I normally end my reviews by briefly listing the strengths and weaknesses of the product under review and start with the weaknesses, but that is difficult to do with the Perlisten S7t speaker since it doesn’t have any real weaknesses. I could say that it is rather pricey, at $16k for a pair, but that would imply that it is not a good deal, and I think that it is a good deal. There are a lot of great speakers in that price range, but Perlisten pushes the design envelope so far that I have to say that the S7ts would be my first choice were I shopping for tower speakers at that price point. They are expensive speakers, but they are also a good value at the same time.

I could critique them for being somewhat large and rather heavy, but then again, as was mentioned before, shoppers for tower speakers in this price range will not be bothered by their size or weight. What is more is that they are not unmanageably heavy or large; while I needed help carrying the packaged speakers to my listening room, I was able to set them up myself. These are not behemoths that have a huge footprint nor will they dominate the room so long as they aren’t placed in a small room. If I had to pick nits, I could say that some people might not like their slightly unusual appearance, but I think they look quite nice, and again, shoppers for tower speakers in this price range probably aren’t looking for a wallflower, so even that criticism doesn’t hold. Anyway, you can never please everyone all the time with loudspeaker aesthetics.

So, without any real weaknesses, are these “perfect” speakers? I wouldn’t go so far as to call them perfect but rather excellent at what they set out to accomplish. But then again, at $16k for a pair of loudspeakers, I think that buyers have the right to expect excellence. Some brands do not deliver at that pricing, but the Perlisten S7t speakers do. The audio performance is superlative from top to bottom. These are one of the most accurate speakers that I have reviewed and also one of the most dynamic. The build quality is impressive and exhibits the exquisite attention to detail that would be expected from their pricing. They are cool-looking speakers and are sure to draw inquisitive comments from visiting friends who see them.

S7t logo2  S7t hero pair2

The audio performance of the S7ts is superlative from top to bottom.

Unlike many other tower speakers in their price class, they can be listened at a close distance without any loss of sound quality, which is made possible by the driver array. I want to put more emphasis on this since this is one of the big reasons why I feel they have an edge over competing speakers. The S7ts have a flexibility that is unusual in this class; seating distance does not matter very much with them. Here are some state-of the-art flagship tower speakers that would work just as well in a small bedroom as they would in a large home theater. The reason is that the sound emanating from the drivers integrate at a much closer distance than normal and also because the tweeter is set at a more sensible height than so many large tower speakers. What is more, the directivity control on the vertical axis provides for a uniformity that is rare for speakers in this segment, and this means the sound is very predictable as a matter of listening altitude. This is a much more significant aspect of high-end home audio than many speaker companies seem to give it credit for; after all, how many people are actually listening to their speakers at a bus-length distance? Maybe some people want a speaker with a lot of “wow” factor but don’t have a large room that so many of those “wow” factor speakers need to sound good. The S7ts have that “wow” factor without sacrificing sound quality in a small room or close listening distances.

S7t pair5They are a true full-range speaker with solid bass down to 20Hz, and they do NOT need a subwoofer at all for low-end assistance. Adding subs can still be beneficial in smoothing out room modes, but they aren’t going to add a lot more dynamic range unless you like extremely hot bass. With a relatively high sensitivity of 92dB, they don’t need a monster amp to get loud, but they can handle a monster amp if you want to get super-loud. And if you want bragging rights of having the only THX Certified Dominus Large LCR rating, these will give you that.

The S7ts are one of the most accurate speakers that I have reviewed and also one of the most dynamic.

Bringing this review to a close, the Perlisten S7t are outstanding speakers for both two-channel applications or as a part of a front-stage in a killer surround sound system. You can spend more money on loudspeakers than these, but I’m not sure that there are any significant gains to be had in terms of sound quality. These are very accurate, and if you aren’t after accurate tonality, they have such finely controlled directivity that they are highly amenable to equalization. There are gains that can be had in getting prettier speakers, and there are extreme speakers with an even wider dynamic range, but the S7ts do everything well- and a lot of things much better than just ‘well.’ In my opinion, they are some of the best all-around loudspeakers that can be had at the moment at any price. They are aspirational loudspeakers designs that can put an end to the upgrade cycle for many, or just a way to skip past incremental upgrades and land on a true endgame sound system. 

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

  • StarStarStarStarStar — Excellent
  • StarStarStarStar — Very Good
  • StarStarStar — Good
  • StarStar — Fair
  • Star — Poor
MetricRating
Build QualityStarStarStarStarStar
AppearanceStarStarStarStar
Treble ExtensionStarStarStarStarStar
Treble SmoothnessStarStarStarStarStar
Midrange AccuracyStarStarStarStarStar
Bass ExtensionStarStarStarStarStar
Bass AccuracyStarStarStarStarStar
ImagingStarStarStarStarStar
Dynamic RangeStarStarStarStarStar
Fit and FinishStarStarStarStarStar
PerformanceStarStarStarStarStar
ValueStarStarStarStarStar
About the author:

James Larson is Audioholics' primary loudspeaker and subwoofer reviewer on account of his deep knowledge of loudspeaker functioning and performance and also his overall enthusiasm toward moving the state of audio science forward.

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Recent Forum Posts:

Trell posts on June 02, 2021 13:10
Trebdp83, post: 1487196, member: 43634
Since this thread is already a long way off of the main road and into the cornfield, I think “room correction” is a misnomer. The software isn't doing anything to the room at all. It is trying to produce the best sound while compensating for the acoustics of the room. I think is should be called Room Acoustics Compensation. I mean, who wouldn't appreciate a nice RAC?

In the glossary in the GLM v4 manual the term AutoCal is explained as “Genelec automatic room response calibration method”. Close enough to your suggestion, I guess.
Pogre posts on June 02, 2021 12:54
lovinthehd, post: 1487138, member: 61636
Or it's not Audyssey causing the hiss particularly, but rather the pre-pro manufacturer who installed it. I have a variety of avrs with Audyssey, hiss has never been an issue (and it would be for me if it was the cause, I'd return the electronics).

ps in reading many many threads on the subject, can't say anyone else reported hiss except you.
Yeah I've never heard any hiss either, and it would definitely piss me off if I did.

I will say my comments are mainly about bass, below the transition frequency. Above that I can see the argument for not wanting to use rc if you have good, neutral speakers to start, but most speakers in most rooms are going to have issues below the Schroeder frequency and could use some help.
Trebdp83 posts on June 02, 2021 12:38
Since this thread is already a long way off of the main road and into the cornfield, I think “room correction” is a misnomer. The software isn't doing anything to the room at all. It is trying to produce the best sound while compensating for the acoustics of the room. I think is should be called Room Acoustics Compensation. I mean, who wouldn't appreciate a nice RAC?
shadyJ posts on June 02, 2021 05:20
Dan Nagar, post: 1487137, member: 95980
can't comment on Audyssey ,as i have no experience with it .
i have used a few RC system in my past and now using only Dirac.
Dirac is the only room correction that I think is worthwhile for a full range correction. While I haven't used Audyssey limited to bass range, my hunch is that it is probably OK for just the transition frequency and below.
Dan Nagar posts on June 02, 2021 03:18
lovinthehd, post: 1487138, member: 61636
Or it's not Audyssey causing the hiss particularly, but rather the pre-pro manufacturer who installed it. I have a variety of avrs with Audyssey, hiss has never been an issue (and it would be for me if it was the cause, I'd return the electronics).

ps in reading many many threads on the subject, can't say anyone else reported hiss except you.
thats definitely an option - for example - Dirac adds about 6db boost the when its engaged, that can add hiss if there a gain structure issue between pre/pro.
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