Perlisten S7t Tower Speaker Review

[Matthew J Poes]

These seem like really impressive speakers, that actually do contain some well thought out novel features that advance the art from the norm. This has been achieved without absurd impedance and phase angles. The world continues to be awash in expensive so called 'high end' speakers, that when you really get down to it are not very good. I agree these speakers are a bargain.

I think these speakers would handle the LFE channel. So with a pre pro and a couple of power amps, you could use both the line outs and the balanced XLRs and mix in the LFE output to the bass section. This is what I do. I firmly believe in an integrated full range speaker system that does not need spaced subs. Having had the experience of this approach for 15 years now, I do believe that is optimal.

The fact that speech was very good without a center, attests to the fact that these are very good speakers. There would be few, if any centers on the market currently that would not detract from these speakers.

There really is a place for good truly full range speakers in the HT environment.

But! Besides the fact that you can simply use three of them to have a perfect center, they also offer a horizontally aligned center that is basically this speaker on it's side with the waveguide turned. It measures equally well and has identical timbre and dynamic range. So they do make a center that perfectly matches the speaker. Center channel speakers rarely measure all that well and don't typically match the L-R speakers. This one really does.

 

[Matthew J Poes]

@Matthew J Poes just in case I go a traveling....can you advise if an audition would be available in Portland OR or San Francisco CA?

What do you mean? What addition?

 

[shadyJ]

What do you mean? What addition?

He is asking if it's possible to hear these speakers in those areas at a dealer. The people to ask would be fidelity imports which are Perlisten's dealer. Perlisten is planning on exhibiting at CEDIA this year so if you are around Indianapolis in early September you can hear them there. They are also contemplating possibly exhibiting at AXPONA for those who will be in the northwest burbs of Chicago in late October.

 

[ErinH]

Perlisten is planning on exhibiting at CEDIA this year so if you are around Indianapolis in early September you can hear them there.

Sweet! I'm planning on making the drive up this year.

Will you be there? Will be nice to meet some fellow reviewers. We gotta stick together. Especially at a trade show where we may be more prone to being jumped. Especially me with my not-so-nice reviews as of late.

 

[Pogre]

I read the article, but maybe I didn't read it clearly enough. This is the sentence that threw me off:

This is done to create an acoustic beamforming effect where all the drivers sum up on an intended listening angle and subtract elsewhere.

This chart shows excellent dispersion characteristics. There's plenty of sweet spot to go around. These look like astoundingly good speakers.

 

[shadyJ]

Sweet! I'm planning on making the drive up this year.

Will you be there? Will be nice to meet some fellow reviewers. We gotta stick together. Especially at a trade show where we may be more prone to being jumped. Especially me with my not-so-nice reviews as of late.

No plans to attend CEDIA. If you are into mainly just loudspeakers, you would probably find more of interest at shows like RMAF or AXPONA. More speakers and better listening conditions.

 

[Matthew J Poes]

You lost me as soon as you explained "beamforming". At least, if I'm understanding correctly, these speakers are designed to sound perfect in one, extremely narrow, section of a room, and basically like crap everywhere else.

My next upgrade will only be to something that expands the sweet spot, not contracts it.

There is also a common misunderstanding in the statement you made. The common misunderstanding is a misapplication of a logical follow, that if a speaker has wider dispersion, it must have a wider sweetspot. That is not true. Take a look at the videos where I covered this:

and

In this I explain how I define "sweet spot" and then how a constant directivity speaker can actually expand the sweetspot rather than narrow it.

Now in this case, the vertical directivity control is serving a different purpose. What James was getting at is that ceiling reflections are perceived a strong monophonic cues. They can potentially dominate our sense of timbre. They have no benefit to our sense of spaciousness and actually degrade imaging. So controlling them can improve sound quality which is what this is doing. Basically, vertical directivity control is beneficial because strong ceiling and floor reflections have no real benefit. What people sometimes confuse is that this narrowing of the vertical directivity does is make it so that the optimal sweetspot is smaller. But it's actually not. With a speaker like this, the vertical response remains very even over a wide enough range that you couldn't really possibly listen in a way that would put you in the degraded response. The response remains very even too. It just gets quieter above or below the optimal listening axis. It doesn't become ugly and corrupted. With most speakers, the vertical response tends to get really ugly with nulls.

 

[Matthew J Poes]

No plans to attend CEDIA. If you are into mainly just loudspeakers, you would probably find more of interest at shows like RMAF or AXPONA. More speakers and better listening conditions.

Don't listen to James! I plan to go to CEDIA with Gene this year. Still need to plan that, but as of today, I am planning to do that. I haven't been to CEDIA myself, and it's not the place for speakers, but it is a cool place for HT and tech generally. Great place to make contacts.

 

[Matthew J Poes]

He is asking if it's possible to hear these speakers in those areas at a dealer. The people to ask would be fidelity imports which are Perlisten's dealer. Perlisten is planning on exhibiting at CEDIA this year so if you are around Indianapolis in early September you can hear them there. They are also contemplating possibly exhibiting at AXPONA for those who will be in the northwest burbs of Chicago in late October.

Ahhhh...Yeah contact Fidelity. My understanding is that they have AXPONA and Florida Audio show rooms, but may be playing it by ear.

 

[ErinH]

No plans to attend CEDIA. If you are into mainly just loudspeakers, you would probably find more of interest at shows like RMAF or AXPONA. More speakers and better listening conditions.

I'm just planning on going because it is within a reasonable driving distance from me and I know some other guys going I want to meet up with. I've never been to any of these type of shows so it'll be a neat experience.

I would love to go to RMAF one year but I just don't see that happening for quite a while. October is a very busy month for my family with birthdays and vacation.

 

[ErinH]

Don't listen to James! I plan to go to CEDIA with Gene this year. Still need to plan that, but as of today, I am planning to do that. I haven't been to CEDIA myself, and it's not the place for speakers, but it is a cool place for HT and tech generally. Great place to make contacts.

Sweet! I'll see you guys there (barring anything unplanned stopping either of us).

 

[kini]

Wonder how the JTR 215RT compares?

 

[gene]

Don't listen to James! I plan to go to CEDIA with Gene this year. Still need to plan that, but as of today, I am planning to do that. I haven't been to CEDIA myself, and it's not the place for speakers, but it is a cool place for HT and tech generally. Great place to make contacts.

Given the choice between CEDIA and other trade shows, CEDIA is the most important to attend IMO as it has the most contacts present in our industry, education, and very cool demos too.

 

[Matthew J Poes]

Wonder how the JTR 215RT compares?

I reviewed and measured the 212RT and have certainly heard the 215RT. It's just a very different product. Much narrower dispersion. Response of the JTR stuff is great, but it's not this great. On the other hand, JTR plays that much louder. Where as these can hit 117dB, the JTR's, at the same distance, can exceed 130dB.

 

[Eppie]

There is an interview with CEDIA's Walt Zerbe on S&V regarding A/V Standards.

 

[Jerkface]

There is also a common misunderstanding in the statement you made. The common misunderstanding is a misapplication of a logical follow, that if a speaker has wider dispersion, it must have a wider sweetspot. That is not true. Take a look at the videos where I covered this:

and

In this I explain how I define "sweet spot" and then how a constant directivity speaker can actually expand the sweetspot rather than narrow it.

This is great information, and I definitely plan to watch your videos after work (thankfully only 20 minutes from now!)

But my misinterpretation was rooted in my failure to consider that speakers could be engineered to reduce Y axis dispersion without reducing X axis dispersion.

With most speakers, the vertical response tends to get really ugly with nulls.

Of this there is no doubt, which is why I preach the gospel of room treatments to every audio enthusiast I encounter. Thousands upon thousands of dollars in buying and selling gear and hopelessly searching for the perfect speakers for your room can be saved by simply measuring and then treating the room with simple stuff like DIY bass traps and wall-and-ceiling-mounted acoustic panels.

If your room is right, every speaker performs better in it.

 

[Matthew J Poes]

This is great information, and I definitely plan to watch your videos after work (thankfully only 20 minutes from now!)

But my misinterpretation was rooted in my failure to consider that speakers could be engineered to reduce Y axis dispersion without reducing X axis dispersion.



Of this there is no doubt, which is why I preach the gospel of room treatments to every audio enthusiast I encounter. Thousands upon thousands of dollars in buying and selling gear and hopelessly searching for the perfect speakers for your room can be saved by simply measuring and then treating the room with simple stuff like DIY bass traps and wall-and-ceiling-mounted acoustic panels.

If your room is right, every speaker performs better in it.

This is no doubt true. Where the speaker becomes the better option is in how the treatment behaves against the incident reflection. So if we consider the spectral balance or really the frequency response of the reflection off an absorber (and how much it has actually been absorbed), we find that the reflection off an absorber is itself pretty ugly. 1" and 2" panels are no doubt the worst, but 4" panels aren't really better enough. They still cause problems. I've actually been proposing to ASTM to consider an alternative measurement technique for absorbers that utilizes a polar response measurement of the reflection (normalized to the direct axis unabsorbed reflection). This would let you see how the reflection looks at different frequencies and different angles, much like diffusers are analyzed now.

But there is an easier solution. Don't use an absorber at a first reflection point. Leave it to be a direct reflection and utilize a speaker that controls the directivity instead. This ensures the reflection response matches that of the listening window response.

Here is the measurement that Floyd Toole shows that really highlights the problem. A 2" panel becomes somewhat unuseful as a first reflection absorber by 750hz. I have repeated this experiment with 4" panels and what I found was that the bigger panel with higher density material operates better down to around 400hz, but is more reflective at mid/high frequencies. Ideally you want that reflection absorbed by -20dB over a fairly wide bandwidth, at least 500hz to 10khz, but of course, wider is better. You want it to be flat too, the bigger problem tends to be when, as you see here, its very uneven. While a 90dB direct signal and an 80dB reflected signal only combine to raise it by a quarter decibel, it is still audible because of the direction. Further, you have more than one reflection, so the total amount raised is a bit higher, closer to 1.5 decibels for a ceiling reflection off a 4" panel.

I've been talking to the folks at IRIS about their 3D IR software and if all goes as planned (and they ever get less busy) I hope to be able to show people what this looks like in real life with very concrete in-room measurements.

 

[Jerkface]

Here is the measurement that Floyd Toole shows that really highlights the problem. A 2" panel becomes somewhat unuseful as a first reflection absorber by 750hz. I have repeated this experiment with 4" panels and what I found was that the bigger panel with higher density material operates better down to around 400hz, but is more reflective at mid/high frequencies. Ideally you want that reflection absorbed by -20dB over a fairly wide bandwidth, at least 500hz to 10khz, but of course, wider is better. You want it to be flat too, the bigger problem tends to be when, as you see here, its very uneven. While a 90dB direct signal and an 80dB reflected signal only combine to raise it by a quarter decibel, it is still audible because of the direction. Further, you have more than one reflection, so the total amount raised is a bit higher, closer to 1.5 decibels for a ceiling reflection off a 4" panel.

This is why I specifically mentioned bass traps - you definitely don't want to just hang panels without corner traps, or your room will sound dead and you'll still struggle with bass response issues.

And yes, if the room is especially unruly or bright, clouds are a far better solution than flat panels, because now the reflections themselves are being absorbed by the various depths and shapes of the cloud array. They're more expensive, or at least more difficult to engineer if you have to DIY, but they definitely work better.

 

[Jerkface]

Just a followup:

Watching the first video, and I screencapped this specifically:

This, along with your assertion in the video about live recordings versus studio recordings et al, seem weird to me, because I have a pair of extremely narrow dispersion speakers (Belle Klipsch), and we listen to a ton of live recordings. Even my wife, who is a complete novice regarding acoustics and sound, finds it remarkable how immersive an experience it is listening on this system, "as though you're right there in the audience" is a frequent comment from her.

Granted, there are a lot of moving parts involved here, such as the fact that I do NOT toe the speakers inward to our primary listening space (an aesthetic choice I had to make to keep the peace) and the fact that this is a very, very live room, with glass sliders and tiled floor (though there is a carpet and the furniture is fabric), and I haven't treated it at all yet. The big advantage I have regarding treatment in this room is the utter lack of bass nulls, because the room is L-shaped and has numerous outcroppings and doorway/entry points that disrupt virtually all the parallel surfaces except floor/ceiling.

But I did find it interesting, anyway. Otherwise, it's a fascinating discussion.

 

[D Murphy]

Thanks James four your usual thorough and fully documented review. I hope I will have an opportunity to hear these beasts. The design decisions made raise some interesting issues. First, and most obvious, the complexity of the design, including the number of drivers and the unconventional crossover topology, would clearly have been far easier to implement with an active dsp approach, and the results might well have been even better. The explanation is equally clear--active audiophile speakers just aren't very popular, a fact that keeps me in business but is probably irrational.

The much more complicated issue is that of controlled vertical directivity. Reducing floor and ceiling reflections in a controlled manner certainly has intuitive appeal, and I participated in an experiment with a local electrical engineer to see whether such a response pattern could be implemented in a tower version of my BMR using concepts borrowed from radar radiation theory, which was my friend's specialty. The approach required 7 drivers critically spaced and integrated drivers with asymmetrical crossover slopes, and differing output levels for the two sets of BMR midrange drivers. It could be that the theoretical basis was similar to that used by Perlisten, although as the picture below shows, no wave guide was involved. In addition to the "radar" crossover slopes used to control and restrict vertical directivity, I also developed a perfectly conventional crossover using garden-variety 4th order Linkwitz-Riley slopes with no particular consideration of vertical directivity, which was quite ragged given the layout of the drivers.

The Radar version of the tower pretty much hit the target radiation pattern, and the vertical dispersion was definitely narrower and more even than for the conventional crossover slopes. I thought the Radar version sounded great--clear as a bell and very neutral. I thought the regular tower sounded great--clear as a bell and very neutral. I just listened to Erin's very interesting interview with Floyd Toole, which touched on vertical dispersion issues. In uncharacteristic fashion, Floyd punted when it came to whether or not there were audible virtues to restricting vertical dispersion. He claimed that people are so used to hearing floor reflections in real life that listeners thought one of his speakers that limited floor bounce just sounded kind of weird. His remarks on ceiling reflections were less focused, but unlike his opinions concerning just about every other aspect of sound reproduction, Floyd just shrugged his shoulders on this one.

All of this isn't to throw any doubt on the quality of the Perlisten speaker. The measurements pretty much tell the story. But I don't think we're at the point where we can say with any certainty that Perlisten's attention to vertical directivity is an important contributor to James' enjoyment of the speakers. I think we all need to keep an open mind on this issue and recognize that the returns aren't in on this one yet.