Crosszone CZ-8A Headphones

Crosszone is a specialized audio company, founded in 2016 in Japan by the Taiwanese company Asia Optical Inc., a manufacturer of lenses and optical systems. It is headed by Mr. Robert Lai, and the first product was the CS-1 headphones. We are testing its latest product, the CS-8A headphones.

The headphone selection on the market is huge today. The most popular are wireless, usually in-ear models, and above all AirPods from Apple. Analysts say that 14 million were sold in 2017, 35 million a year later and as much as 60 million in 2019. The 3rd generation headphones will significantly improve this result. It is also said that AirPod sales account for around 60% of wireless headphone sales in general (more: "AirPods" password, en.WIKIPEDIA.org, accessed 04/25/2022).

Financing of the headphone companies at an unprecedented level has resulted from the ubiquity of smartphones, tablets and laptops, in a word, mobile sound sources. Research and development of this type of products require huge financial investments. Earlier, even before the Apple era, it was a thin stream that usually fed the professional market, later the popular one, and only at the very end the audiophile market. So we, audiophiles, also benefit from this boom.

In addition to patents that are jealously guarded by companies, there are solutions in the info-sphere that cannot be patented, usually evolving from some earlier patents that have already expired or generic solutions. The unique combination of these features, that is a lot of money, a multitude of ideas, as well as young people getting used to the idea of headphones, made the market for perfectionist audio richer and more diverse than ever before.

Perhaps this is why the Crosszone company was founded in 2016 to, initially, offer only one type of headphones, the CS-1 model. This is an extremely interesting case of a combination of external financing and production in another country. The parent company of Crosszone is Asia Optical Inc., a Taiwanese specialist, a company that produces lenses, for example for smartphones, as well as optical systems. However, Crosszone was founded in Japan, the research department is also based there and the headphones are manufactured there.

Its boss, Mr. Robert Lai, must be an audiophile, because the solutions found in his products refer to the very "core" of the audiophile trend. The most important—the one that defines the entire company—was included in its name, so it had to be prior to the company itself. "Crosszone" speaks of a technique aimed at freeing the sound "from the head" of a listener. And it is precisely its "closing inside a head" that is most often quoted as the reason for reluctance towards headphones in general. In addition, the company does it in its own way.

CS-8A

The CS-8A model is the latest and only the third headphones in the six-year history of Crosszone. Higher in the price list, produced from the very beginning, are the CS-1 (PLN 13,990), and below—in this context—the inexpensive CS-10 (PLN 3,990).

The CS-8 are a closed design, they use dynamic drivers and are wired headphones. However, their design is, as already mentioned, unique. The large cups contain as many as three drivers made of beryllium. Two of them, the tweeter and the mid-woofer—the similarity to multi-way loudspeakers is justified—form the basic system, and the third one works in a separate chamber and is connected to the opposite channel. These techniques were called Acoustic Resonance Technology (ART) and Acoustic Delay Chambers (ADC), respectively.

Company’s material describe them as following:

The CZ-8A from Crosszone are unique headphones which, thanks to their original technology, achieve the effect of "external sound localization." Unlike conventional headphones which deal with a problem known as "internal sound localization" (where the sound sources appear to be inside the head), the CZ-8A uses acoustic resonance technology (ART) and acoustic delay chambers (ADC) to achieve natural and spacious sound field. Thanks to this, we simulate the sensations and sound known from listening to music through stereo speakers.

GETTING OUT OF THE HEAD

So we are dealing with designs in which the emphasis was placed on simulating the sound from the loudspeakers. This is why we need a diaphragm with delayed (acoustically) second channel sound.

Under normal conditions, the sound wave from the left channel first reaches the left ear and then the right ear, but it does that with a delay and is shaped by the so-called "Head shadow," thanks to which we hear spatially, also known as "head-related transfer function" (HRTF). In short, when listening through two speakers, both ears hear both channels—the left ear directly the left channel and the right channel changed by HRTF, and the right ear directly the right channel and the left channel modified by HRTF (more HERE).

Attempts to "get the sound out of the head" have been carried out for years, both on the hardware and recording level. The most successful and at the same time the least common—what a shame!—is a method of recording sound material called binaural. As we wrote in the article BINAURAL. 120 years in the kingdom of headphones, recordings of this type use two microphones, most often omnidirectional, placed in the so-called artificial head ("dummy head"). It has contoured ears, nose and head designed to imitate the head of a real human. Thereby, the signal is modified with the HRTF. (more HERE).

The illusion of being in real space can also be simulated electronically, both in analog and digit domain. The easiest way to do that is with electronic circuits known as "cross-feed." By manipulating the signal (addition and subtraction) delays corresponding to the HRTF are introduced. Recently, we have seen this type of solution in the Jay's Audio DAC, but in almost every player in a smartphone some kind of chip is also available. And finally there are albums encoded in this way, with the most popular Dolby Atmos and 360º Reality Audio systems, we wrote about in October last year (more HERE).

TECHNOLOGY

Crosszone included its solution in its name. The CS-8A uses a "cross-feed" type circuit, but made not with electronics, but passively. The company refers to this method as an "acoustic lens," pointing to the fact that thanks to its solution it can shape the front of a sound wave. An additional driver is mounted in large aluminum cups, to which the signal from the second channel is fed. This is why the Crosszone cables are unusual—each one has four complete cables (ground and signal). The signal is taken in via jack plug, from the source side.

The driver in question, with a diameter of 35 mm, was placed in a chamber separated from the main housing. The sound comes out through a small hole and is added to the main sound with a delay. To further improve the shifting of the sound image to the front, in front of the head, the ø 23 mm tweeter is angled slightly to the front. This is a historically sanctioned method, to mention such models as the AKG K1000, most of the Ultrasone models and others. In turn, the woofer (ø 40 mm) does not radiate directly, but through the resonance chamber, which adds an echo to the sound.

With the headphones one gets two cables: a 1.5 m long with a mini-jack plug (ø 3.5 mm) and a longer one, of 3.5 m, with a large jack (ø 6.35 mm). Both are made of OFC copper. They do not look very attractive, but it will be difficult to replace them due to unusual plugs—from the headphone side they are connected through two four-pin mini-jacks. Let me add, that the company also offers a balanced cable for an additional fee.

The CS-8A has large, closed cups with cushions of an unusual shape. The headband connects to them with flexible hinges. I have to say that although they are not lightweight headphones, they are great to wear. They stick well to the head, do not fall off, and yet their pressure is not tiring. The manufacturer declares a frequency response between 20Hz and 40kHz and an impedance of 75 Ω. So these are headphones with a lower than standard impedance. They are also heavier than usual—they weigh 435 g, which is more than the HiFiMAN HE-1000 v2 planar-magnetics, which I use every day (420 g).

SOUND

HOW WE LISTENED

The Crosszone CS-8A headphones were listened to in the High Fidelity reference system. The listening sessions were carried out in two different systems, with three different points of reference. The basic system was a mobile set consisting of a Samsung A52 smartphone equipped with an external digital-to-analog converter ALO Audio Pilot|PL|, with the USB AUDIO PRO application.

The second system served as the actual reference for me. It consisted of the LEBEN CS600X tube amplifier (PLN 25,900, review HERE) and planar-magnetic headphones, HiFiMAN HE-1000 v2 (PLN 15,000, review HERE), AKG K271 Pro and Beyerdynamic DT-700 Limited Edition 32 Ohm. In this case, the Ayon Audio CD-35 HF Edition SACD player was the source of the signal.

Recordings used for the test | a selection

SUPER AUDIO CD/COMPACT DISC

Miles Davis, The Complete Birth of the Cool, Capitol Jazz/EMI 4945502, CD (1957/1998).
Mark Knopfler, One Take Radio Sessions (The Trawlerman's Song EP), Mercury 9870986, Studio Digital Clone CD-R (2005).
Dominic Miller & Neil Stacey, New Dawn, Naim naimcd066, CD (2002).
Istanbul, perf. by Hespèrion XXI, Jordi Savall, Alia Vox AVSA 9870, "Raices & Memoria, vol. IX", SACD/CD (2009).
Marek Bilinski, Best of the Best, Bi.Ma. BiCD-10, CD (2014); review HERE.

FILES

Santana, Africa Speaks, Concord Records/Tidal Master, FLAC MQA 24/96 (2019).
Soundgarden, Superunknown, A&M Records/Tidal Master FLAC MQA STUDIO 24/96 (1994/2014).
Eric Clapton, The Lady in The Balcony: Lockdown Sessions (Live), Universal Music Group/Tidal Master FLAC MQA 24/96 (2021).
Mary Komasa, Degenerate Love, Warner Music Poland/Tidal, SP, FLAC 16/44,1 (2019).
Antonio Carlos Jobim, Stone Flower (CTI Records 40th Anniversary Edition), CTI Records/ Tidal Master, FLAC MQA Studio 16/44,1 (1970/?).
Kingdm, Your Love (feat. Soran & Reo Cragun), Capital Records/Tidal Master, FLAC MQA 24/44,1 (2018).
Miles Davis, Kind of Blue, Columbia | Sony Legacy/Tidal Master, FLAC MQA Studio 24/96 (1956/?).

I started listening to the Crosszone headphones, unusually for this class of product, because by listening to music streamed from Tidal using a smartphone. The Samsung A52 has the USB Audio Player Pro program loaded by me, which allows me to send out an unmodified bit-perfect signal decoded from MQA. It is converted to an analog signal and amplified by the AOL Audio Pilot DAC/headphone amplifier—so it's good. Which does not change the fact that it is an absolutely basic audio system.

However, I cannot forget that many years ago I did not predict that people would wear large headphones moving around the city and that their primary source of sound would be a smartphone, and in exceptional cases a portable file player. This time, trying to make up for it, I assumed that some of the people who might be interested in the CS-8A would use them this way.

As it turned out, the basic character of the sound of the Crosszone headphones is easy to determine. Perhaps I should say right away: "the kind of spectacle they offer," because it would be closer to what we get with them. The most important promise that their producer makes to us, that is one of "getting the sound out of the head" is carried out very smoothly, and its effects are unequivocally positive.

Listening to the Winter by the Voices 8, Black Mother by Stephan Micus or—and on a different note—Brazil (Alka Aquarela do Brasil) by Antonio Carlos Jobim with that in mind, I clearly heard that they were extremely spacious and the sound heard through the speakers on the axis, in front of me, was actually in front of me. Not too far out, it's not like we'll suddenly "see" performers three meters behind the wall. But still, they weren't inside my head anymore.

Elements distributed in the channels, especially those out of phase, i.e. supporting spatiality, with the CS-8A were spread widely on the sides. It even felt like they were presented to the side and behind me. It was an amazing surround sound effect. As far as I remember, the best Ultrasone headphones, such as the Edition 5, went in a similar direction in shaping the space. Even those, however, did not build such a well-filled and information-filled "dome of sound" as the Crosszone.

The transition to the "big" system only deepened these observations. Even the most difficult to play monophonic recordings, such as from the 2008 re-edition of the Miles Davis album entitled Birth of the Cool, thanks to the Japanese headphones, sounded less "mono-like" and more "binaural"—minus the spatial effects. I mean that the sound with them broke away from the headphones and to a large extent also from me. It was still an on-axis recording, but that axis was also width and depth and the foreground was in front of me.

Our albums

Miles Davis, The Complete Birth of the Cool. Capitol Jazz/EMI 4945502. COMPACT DISC 1957/1998

Lasting under 36 minutes, Miles Davis' album has become legendary. It laid ground for the career not only of the trumpet player, but also of the musicians who performed with him at that time. Artists such as Lee Konitz, Garry Mulligan, Al Haig, John Lewis, Max Roach and Kenny Clarke, to mention only the biggest names.

And it was almost never recorded, because the bosses of Capitol Records were not interested in the music presented by the band. As Pete Welding wrote in the accompanying essay, we owe it to Walter Rivers, who was briefly employed by the company. On January 21st and April 22nd, 1949 and March 9th 1950 twelve tracks were recorded, some of which were initially released on 78 rpm discs and only a few years later (1954) in the form of a 10" record including eight tracks. We had to wait for the complete set of recordings until February 1957, when they were released on a 12" LP.

The Compact Disc version released in 1998, which I would like to recommend to you, is one of the best I know. Its co-producer and the person responsible for the sound is Mark Levinson himself. He used devices from his company Cello, especially a brilliant equalizer called Palette. Admittedly, it was only in 2000 that individual, original tapes were used, but it is the Levinson remaster that I like the most. An additional value of this version is the fact that there is also a live performance of the Davis's band from 1948 on the same disc, with similar material.

The sound of this version of Birth of the Cool is perfect. The great dynamics and saturation of the sound in recordings before, let's say, 1955, are noteworthy, being a rarity. The sound is well-balanced and dense. The band’s extremes seem particularly interesting. The treble is delicate, vibrant and exceptionally resolving. Similarly, low tones are, maybe not so selective, but with the right weight and extension. As in the Deception, when a trombone with a nice filling comes in before the end of the second minute.

This is, of course, a mono recording from the first years of using the tape as a sound carrier. Nevertheless, it has the truth and naturalness that is absent from many later, much better technically, recordings.

The leap from the previous recordings, made on acetates, is clearly audible when we go to the concert creating together with the Birth of the Cool a complete album titled The Complete Birth of the Cool. Narrow bandwidth, low dynamics, low transparency—that's obvious. So Davis's album remains a classic not only in terms of music, but also recording. And the Mark Levinson remaster only emphasizes these qualities.

The space of the tested headphones is one thing - a complete success—and tonality—is another. And this is something that you will have to deal with and consider whether you are willing to "pay" in this way for the advantages offered by the Acoustic Resonance Technology and Acoustic Delay Chamber techniques. The thing is that the Crosszone CS-8A have a very clearly shaped timbre, different from all headphones I have had at home. They are closest to the sound of studio headphones, such as the AKG K-271 Studio and the Beyerdynamic DT-990 Pro (600 Ω), but even in such a comparison they are clearly different.

In a nutshell, it is based almost exclusively on the midrange. At first, you can even get the impression that it is muffled. This is the inevitable effect of using a third diaphragm to simulate the sound of the second channel and canceling out some of the sounds. I know it from many other solutions and so far there is no way around it.

So all recordings with the CS-8A had a soft character, they were never sharp or bright. They also did not have a strong bass foundation. In the recordings of Mary Komasa and Kingdm, the energy of the music was very well conveyed, I had a nice pulsation in the bottom of the band and a nice treble, but even in their case it was only an addition to what was happening in the midrange.

Also, elements located by the producers close to us, warm and tangible, will be shown further away, in addition with a lot of reverberation. This was the case with Mark Knopfler's vocal recorded during radio session for the One Take Radio Sessions (The Trawlerman's Song EP), which I have in the CD-R version from the studio, it was also the case with the guitars of Dominic Miller & Neil Stacey, from the New Dawn presented in an extremely suggestive and close way.

The resolution of the presentation is surprisingly high. And yet this is not how we perceive it. This is because the selectivity is only traceable. At least after switching from classic headphone designs. After some time we get used to it and then the latter start to seem insistent and unnatural in how detailed they are. The CS-8A show a completely different world—a world that is either very "ours" or completely "not ours." There is no hesitation and no "maybe."

SUMMARY

it does not happen often that some new solutions are introduced to the market that help to avoid the biggest problem of headphones, i.e. locating the sound "inside the head." The quotation marks are necessary because it is only the impression we get, not the actual placement of the sound inside our skull. This is why the system proposed by Crosszone seems so interesting to me. It does free the sound—not entirely, but still—from the headphones and it does it very well indeed.

All kinds of recordings sound great with them, from mono to stereo and binaural to electronically spatialized ones. But we also get a completely different tonal balance and a different textuality of the sound with them. This is a sound located further away from us, so not as much "overexposed" as with classic designs. It is focused in the middle of the band, and its extremes are clearly withdrawn. We have fullness, it is not a flawed presentation, but the difference is big and, I would say, decisive.

This is a unique design that you must first listened to before you decide to buy it. However, if it turns out that this is "your" way of sound presentation, then no other headphones will seem worth your interest.

Technical specifications (according to the manufacturer)