Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs

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Prelude​

A while ago, I managed to collect the three TOTL:
the dynamic: LB-Acoustics Mysphere 3.2,
the planar: Hifiman Susvara,
and last, the electrostatic: STAX X9000



And this is the review about the Susvara, which is my favourite one out of the three.

Not lying to you, this is the one I've listened to the most. Writing the review for the Susvara took me the longest time—I found that while writing its review, my thoughts often drifted away, as if a fairy had taken my soul and led me into a paradise. I was completely captivated by the Susvara's enchanting sound, it allows me to genuinely immerse myself.

It almost has a magical quality that makes you want to revisit all your favourite track and listen to it again with the Susvara. Each time, its performance exceeds my expectations and rekindles my passion for listening. You'll find that the songs you've been listening to all along sound entirely different, reinterpreted in a new and amazing way.

Accessory​

A leather carrying case.

The HE1000v2 used to come with a similar leather case in orange colour, but ever since the Stealth version, it was replaced with a cardboard box, which I consider a mistake.

Inside the leather case of Susvara, there's a user manual, which is quite interesting because most of its content is about the design philosophy of the Susvara. It reads more like a 'book'let which is noticeably thicker compared to the manuals for other HIFIMAN products.

Next, you'll find the Susvara and three classic HIFIMAN transparent cables. I had hoped that HIFIMAN would provide something special, or at least a different cable for their flagship model, but that wasn’t the case.

Before we get to the sound, amplification​

I once read this from a fellas head-fier and strongly agreed with it: planar baby tend to sound better when fed with "a healthy bit more of power". Previously, I tried driving the HE6SE V2 and Susvara with the GS-X MK2, but it didn't work out so well. However, when connected to a power amplifier, the HE6SE V2 transformed dramatically—the dynamics became strong, and the soundstage expanded significantly.

In comparison, the Susvara is interesting because, even if it's not fully driven, it maintains its tuning signature. It's more forgiving of the source than the HE6SE V2, but to fully unleash its potential, you need to feed it with more power, much more.

I'm using the Linn Selekt with Organik module as DAC, and the Yamaha A-S3200 as amplifier, the AS3200 is an excellent integrated amp, I mean both visually and sonically. It has VU meters on the front, illuminated by a soft beige LED light when powered on. Watching the meters' dance is a visual-fi in itself.


As an integrated amplifier, it's quite kind for Yamaha to equip it with a headphone jack, albeit the output power of which is merely 50 mW + 50 mW.
Yeah, you see it right, 50 milli Watts, kinda humorous

But when it comes to amplifier output of the AS3200, it got serious 90 W + 90 W power into 8Ω load, and 145 W + 145 W into 4Ω

Many people worry about blowing headphones with excessive power from a power amp, let's do a quick calculation to verify this

Using the formula P=𝑉2/R:

• P is the power in watts
• 𝑉2 (V Square) is the voltage in volts
• 𝑅 is the load impedance in ohms

First, we'll determine the voltage for each given load impedance using the provided power outputs:
For 8 ohms:

• 𝑃=90W; 
• R=8Ω;
• 𝑉 (8Ω)=Square root [𝑃 (8Ω)×𝑅]=Square root [90×8]≈26.83 𝑉

Now, calculate the power for a 60-ohm load, which is the impedance of Susvara:

• 𝑉 (8Ω) =26.83
• 𝑅 (60Ω)=60
• 𝑃( 60Ω)=Square [𝑉 (8Ω)] /𝑅 (60Ω)

=(26.83*26.83)/60
≈719.848/60≈11.997𝑊

Thus, the output power for a 60-ohm load would be approximately 12 watts (per channel).

So, even though the figure of 90W per channel might seem dreadful, considering the 60-ohm impedance load, you wouldn't actually be delivering hundreds of power to the headphones.

Sound​

First Impressions​

Sheer astonishing, it doesn’t even sound like something a pair of headphones should be capable of. The soundstage is immense, and delivering such detailed and clear sound within this vast soundstage is truly remarkable for a headphone. The soundstage is more than most headphones can handle, being very wide with almost no sense of boundaries. You don't feel like the sound is confined or unable to expand further at a particular point; it just naturally extends beyond your head, good in depth and horizontally broad.

The vast soundstage of Susvara really reminded me of my experience using the Rega Brio with an poweramp adapter to drive the HE6se V2, which also had an impressive soundstage. I was deeply captivated by the expansive soundstage that these headphones can deliver, at that moment, I made up my mind that I must experience the soundstage delivered by HIFIMAN's flagship.

Bass/Lows​

As a basshead, I’ll start with the bass. Initially, I expected the Susvara to have a very aggressive tuning, with lows attacking fiercely like a wild beast. Even if not that extreme, I anticipated something powerful and impactful like the HE1000V2 Stealth or HE1000SE. Contrary to these expectations, the Susvara’s bass is almost entirely linear. If you look at Susvara's frequency response curve, you'll notice that its low end is a nearly flat line. It sounds very linear, natural, clear, and appropriate.


Listening to "Almost Love (Stargate Warehouse Mix)," as the drumbeats begin and gradually merge into the main melody, the Susvara’s bass keeps pace perfectly—neither too fast & tight nor slow. Linear: It transitions smoothly from sub-bass to mid-bass, then low bass and finally the lower mids, showcasing a very linear and complete response. Natural: the transition between different bass layers is incredibly smooth, with no unnaturalness because no part of the bass spectrum is overly emphasised, and every detail of the bass is clearly articulated. Thanks to its linearity, the Susvara doesn’t exhibit significant roll-off. It possesses sufficient and appropriate sub-bass detail, allowing the bass layers to be showcased clearly while maintaining the right speed.

What could be improved
When we describe bass, we generally divide it into three segments: sub-bass, mid-bass, and upper bass.

Although the Susvara's bass is accurate, complete, and without flaws, I personally think it would be perfect if it had a bit more slam and a stronger impact in the mid-bass, and I feel that more and more every time I listen to R&B or EDM. Previously I mentioned that I prefer the bass response of the HE1000se, because I lean towards its punchy, impactful bass, which truly resonates with me. The Susvara's bass performance, while its texture and speed are impeccable, due to the linearity, with almost a flat bass response, the impact sometimes feels less powerful, it feels like every time the drum beats, I can't help but move my hands around, trying to act as the drummer making the beat more impactful.

​

Vocal/Mids​

The overall vocal presentation on the Susvara is characterised by its naturalness and authenticity. It captures even the subtle emotions and expressions of the singer with meticulous control over sibilance, even for extended listening sessions, it is without fatigue.

Susvara’s vocals are akin to witnessing a performance in its purest form, where every breath and whisper is crystal clear and impeccably defined, each vocal detail is rendered with a breathtaking level of clarity. And it also excels in delivering remarkably neutral and uncoloured vocals. The vocals strike a perfect balance between warmth and coolness, appealing to purists. They exude a sense of purity, as if each syllable is bathed in pristine light, untainted by coloration or distortion.

Imaging is perfectly positioned, avoiding being too forward or too recessed. This ensures that the vocals remain accurately placed and lifelike, providing a sense of presence without being overwhelmed by instruments or other elements of the music.

Treble/Highs​

The Susvara's treble exhibit an excellent sense of openness, offering a relaxed and comfortable treble overall. While the mids remains smooth, the upper midrange extend beautifully to the treble. It showcases remarkable detail, and wisely, Hifiman didn’t attempt to artificially boost treble or create an overly bright tuning like some of iem do. Instead, the Susvara’s treble is incredibly detailed and free from any harshness, retaining every bit of detail while still sounds comfortable and relaxing. The treble integrates seamlessly with the rest of the frequency spectrum, ensuring that the highs are never overpowering, which really deserves the word 'natural'.

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Tuning: What makes flagship headphones so fascinating?​

I'm going to end with something that‘s perhaps a bit of a departure from the sus's review.

In my previous review of the Stax X9000, I mentioned the term 'smart.' I think those TOTLs have one thing in common: a ‘smart’ tuning. Precisely, what does it means?\
Well in my opinion, firstly, they can grasp the balance very, very well, avoiding obvious deficiencies in certain frequency that lead to shortcomings, such as mids dips causing a recessed vocal imaging; or excessive emphasis on certain frequency, like highs, which eventually resulting in noticeable sibilance and harshness, also, sense of unnatural.

There's a joke that goes like this: A man walks into a psychiatrist's office and says, 'Doc, you have to help me! Everyone thinks I'm crazy because I keep telling them the sky is blue!' The psychiatrist looks out the window and says, 'But the sky is gray today.' The man replies, 'See! Even you think I'm crazy!'

Sometimes, what we need isn't something that's deliberately emphasised. For instance, bass—a strong, impactful bass can be pleasing, but if the bass is so overpowering that it's all you can hear, it loses its appeal. Similarly, with treble, if it's excessively boosted, like insisting to a doctor that "the sky is blue," the already high treble is pushed even higher, such an overly stimulating sound loses its significance as well.

And I feel flagship headphones embody a should be common but rare spirit, which is "smartness". They know how to express things correctly and appropriately, with precise and subtle balancing at the heart of their essence. This is also the essence of the Susvara, where everything is perfectly balanced and just right.

Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs

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A while ago, I managed to collect the three TOTL:
the dynamic: LB-Acoustics Mysphere 3.2,
the planar: Hifiman Susvara,
and the electrostatic: STAX X9000

Although I had already written reviews on local forum, I thought it would be a good idea to write an English version and share it on Head-Fi. Thus, this article was born.

Unboxing​

The X-9000 follows STAX's classic two-layer packaging: a cardboard outer cover and a storage box

Specifically, a Paulownia wood box, known as Kiri in Japanese. This hardwood grows quickly and, thanks to its lightweight, warp-resistant, moisture-proof, and insect-resistant properties, has been used for centuries in Japan to make storage chests.

To be honest, I was hoping for a carrying case like the one that came with the 009. Personally, I think the carrying case of the 007a is much more impressive and useful.

Design​

The moment I took out the x9000, I was already impressed by how well it was made, deeply. If I were to say that there is any headphone that is more of a work of art and symbolises contemporary craftsmanship, I’d definitely nominate the x9000. This is what truly deserves the title of a totl product.

The craftsmanship behind it is so exquisite that most other headphones I have seen pale in comparison.

The housing of the X9K’s driver is made of aluminum, with the golden driver securely fixed within and clearly visible through the open protective mesh. Unlike the Lambda series, there is no cheap plastic hinge used anywhere in the frame.

Metal, metal, all metal! Yes!!! the head spring, case holder, speaker body, and guard mesh are ALL made of metal. This is exactly what I wanted and what justifies the money I spent.


The part of the earpads that touches the cheeks is made of genuine leather, with the rest made of protein leather. (I hope that one day Fostex will adopt a similar approach for their earpads to make the TH900’s pads more durable)

Technology & Improvement​

It seems that most reviews of the X9000 have already covered the MLER-3 driver characteristics. Therefore, there’s no need to repeat that here.

However, I'd still like to discuss an interesting improvement on the X9K: the dust cover. If you look closely, you'll notice that the dust mesh is no longer attached directly to the frame as in previous generations. It has become two layers, with the outer layer placed outside and above the driver frame, supported by six pillars and angled slightly. STAX explained this design choice: "A protective net installed parallel to the sound unit produces direct reflections, which adversely affect sound."


If you're curious about the reason: from an acoustic standpoint, the dust cover functions as a reflective surface for sound waves passing through it. The density and size of the holes in the cover determine how much sound is reflected. In the case of the X9000, compared to the 007A, the holes in the dust cover are significantly larger.

When sound waves encounter the protective mesh, a portion of these waves is reflected back, creating a reflection wave. This reflected wave typically has a phase that differs from the original sound wave produced by the driver. This phase difference can lead to Constructive and Destructive Interference at specific image positions and frequencies.

Constructive interference occurs when the peaks of the reflected wave align with the peaks of the direct wave, amplifying the sound. Destructive interference happens when the peaks of the reflected wave align with the troughs of the direct wave, reducing or canceling the sound, in short, causing distortion. This interplay of reflections and original sound waves creates the interference effect, which can affect the overall sound quality. By increasing the size of the holes in the dust cover, it seems that the x9000 aims to reduce the impact of these reflections, thus minimizing unwanted interference.

Well for me, the biggest benefit of enlarging the holes in the dust cover is that: I can clearly see the shiny golden drivers inside, visual-fi!

What you're most interested in, sounds and comparisons​

Signature in a word​

The X9000 generally has a neutral tuning. From the moment you hear it, you can sense that it delivers a healthy, neutral and balanced sound with no obvious biases, only a slight warmth in the mids/vocal.

Brief comparisons​

The X-9000 is the long-awaited successor to the SR009 and SR009S. Naturally, people will compare its sound to that of its predecessors. However, I must say: it's not the same. The X9000 has an entirely new and independent tuning, it emerges as a flagship in its own right, with a brand-new sound signature.

In my opinion, one interesting feature of STAX headphones is that each generation has its unique tuning and charm. Just as people still yearn for a pair of Omega, you can always find your favorite among different product lines at various price points. This is why even with the X9000, I've kept my 009BK, L300LTD, and 007A.

Comparing to the 007A​

As mentioned earlier, there is no obvious bias for the X9000, unlike the 007a, where you can clearly perceive its warm tonal character. The 007 has a notable roll-off in the sub-bass, which was compensated by boosting the mid-bass and low midrange, giving the bass a more significant presence, nevertheless, this also results in a larger low-frequency imaging and a higher proportion of bass in the sound profile. The X9000, however, has sufficient energy in the bass overall, although there is still a sub-bass roll-off, it sounds more natural than the 007, with deeper extension, making it fuller and more complete. The mid-bass is appropriately controlled, ensuring the bass punchy without sounding unnatural or overly dominant among other frequencies.

Comparing to the 009​

In my opinion, the 009 has an emphasised mids, specifically between 350Hz to 3kHz, making vocals more prominent and closer, creating an intimate feeling as if the singer is right in front of you. This is pleasant, and I absolutely enjoy this characteristic. However, the X9000's midrange and vocal imaging are more precise and realistic. It places the imaging exactly where it should be, with the appropriate size that feels just right. Both headphones avoid sibilance, and the vocal extension is incredibly smooth. This is a particularly striking characteristic of Stax's Omega series.

Comparing to the L300ltd​

Unlike the L300LTD, which has a significant amount of mid-bass but lacks layering and has minimal sub-bass presence due to roll-off, the X9000's bass is more refined. It doesn't have the same large quantity as the L300LTD; instead, it is few but refined (I'll go into more detail on this later). The L300LTD's tuning is more engaging and passionate, whereas the X9000 feels much more serious. Both, however, inherit Stax's excellent vocals performance.

Sound Reviewing Part​

Treble ​

The X9000 excellently showcases the strengths of electrostatic headphones, with a luxurious, smooth, and highly extended treble. It achieves a perfect balance of brightness and extension, making it sound "smart." The highs are controlled to an intriguing extent—if you're looking for the utmost highs extension, you might be disappointed, as the X9000 doesn't emphasise the upper mids like the 009. Instead, it's highly natural and balanced.

I spent a few weeks listening to my familiar tracks, and discovered an interesting characteristic: the mid-high frequencies are filled with detail yet remain very delicate and gentle, never fatiguing. It strikes a perfect balance between being "dark" and "overly bright." It avoids the pitfalls of sounding either "unable to reach high notes" or "going too high and becoming harsh or overly stimulating."

In short, I'm very satisfied with its treble, even though it's not the type that immediately wows you.

Mids​

X9000's rendition of vocals is nothing short of remarkable, displaying an unparalleled mastery over every nuanced detail. With immaculate control over sibilance, it delivers vocals that are velvety smooth, devoid of any harsh edges or unwanted sharpness. Each note flows effortlessly, like a gentle stream winding its way through the landscape of sound.

Bass​

Regarding the bass, the X9000’s bass is well-balanced and just right as well. Unlike the L300LTD, which has a large amount of mid-bass but a rather flat impact, largely affected by roll-off imo. The X9K’s bass is more refined, it doesn't have the overwhelming quantity like the 007A; instead, it presents a much more restrained amount. Due to its neutral tuning, it doesn’t allow the bass to overpower other frequencies. The X9000 provides precisely what a good bass needs: sufficient energy, adequate depth and layer for an electrostatic headphone, and a slight sense of rebounded bass. The X9K meets all these criteria. Its bass is problem-free, in various pop music, it offers drum hits with enough tension and strength to complement the main tune of the song.

Soundstage​

Regarding soundstage, the X9000 performs remarkably well. Compared to the L300ltd series, it’s like moving from the studio to the theatre to listen to a song, the X9000 has a broader soundstage both vertically and horizontally.

However, if I were to speak about the most impressive soundstage, I would still lean towards the Mysphere 3.2. I had the chance of hearing the Mysphere driven by the Zahl HM1 during a demonstration by my friend Sayed. It left a lasting impression on me: it was as if the sound wasn’t coming from headphone drivers, but rather from everything around me. I can’t use the word ‘soundstage’ to describe it anymore, because it was a boundless sound, as if the natural world itself was producing the sounds that coalesced into the music.



The X9000’s expansive soundstage meticulously and precisely places each instrument as if arranged in a ‘theatre,’ reproducing each instrument with exquisite detail. When listening to Beethoven’s Symphony No. 7, you can distinctly and clearly differentiate between the positions of each section. There is a distance between each instrument, they are not overlapping or merging together. The separation between the strings and brass section is particularly well-defined in terms of depth, because in the live section layout, the violin section is positioned in front of the flutes and oboes section. When using headphones with insufficient resolution, the imaging of these sections tends to overlap, making it difficult to distinguish their positions.

But on x9000, you can clearly perceive the closer positioning of the violin sections and the farther placement of the timpani and horn. Each is presented with remarkable clarity. The X9000 excels in presenting the dynamic shifts and nuanced performances of each section in the finale of Symphony 7, the cello melodies, periodically interrupted by the loud, rhythmic blare of trumpets and timpani, are perfectly reproduced overwhelming vitality and dynamics. The bassline’s semi-tonal hum and the extreme dynamic shifts of the violins and violas are vividly portrayed.

Even after the music has stopped, I find myself reluctant to leave my seat or take off the Stax x9000, sitting there and savouring the heavenly music that lingers in my mind.

Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs

​

Background​

With the advent of the era of smartphones without 3.5 jack, various types of TWS earbuds are flooding the market, relieving users from the annoyance of the stethoscope effect and offering noise-cancelling features, it seems that this has also gradually become the mainstream way of listening to music while on the go. With such change, it seems that headphone manufacturers are increasingly joining this trend with brands like Noble, Final, and even Sennheiser have launched their own TWS products, hoping to capture a share of the market.

(Picture: Sky News)
It certainly raises a question: In this era, do portable over-ear headphones still have a place? Can they adapt to the times and find their value?

For me, I discovered the value of the LCD-4z in this context: There are moments when a nostalgic melody pops into my mind, urging me to immediately listen to that song again. However, the thought of having to turn on the USB DDC, power filter, DAC, and then the headphone amplifier, etc. etc., simply thinking the lengthy setup process is enough to make me abandon the idea; besides, by the time I set everything up, the melody may have already faded from my memory.

Sometimes, I just want to enjoy music in a simple way, reminiscent of the days when I could just plug my headphones into my phone and immerse myself in beautiful melodies, instantly. However, I struggle to find flagship over-ear headphones that can be easily driven.

This is where the Audeze LCD-4z truly shines.

Design​

While maintaining the massive 106mm driver, Nano-Scale Uniforce diaphragm technology, Double Fluxor magnet design, and Fazor waveguide technology, the impedance of the LCD-4z is reduced to merely 15 ohms. It's worth noting that the early version of the LCD-4 had an impedance of 100 ohms, which later changed to 200 ohms due to criticisms of driver failures.

In terms of weight, the LCD-4z changes the shell material to aluminum-magnesium alloy, reducing the weight from the LCD-4's 735 grams to 560 grams, these changes undoubtedly make the 4z more portable (Of course, if compared to other portable over-ear headphones, like the Focal Radiance at 435g, there is still place for improvement… but I mean, as long as it’s lighter, it’s better, isn’t it).

The headband features the usual antenna yoke rod design for adjusting the fit. The side logo is a highlight in my opinion, with the gold lettering shining brilliantly under the light.

The carbon fibre headband embodies the lightweight design philosophy to the fullest, and it looks fantastic as well.

Yes, it perfectly fulfils my desire: a flagship headphone that can be easily driven.

Unboxing​

Yeah, a real box


The familiar Pelican-style case comes into view, with the headphones nestled in grey foam padding. The lid's foam has a wave-patterned texture and is very thick, designed to securely hold the headphones in place and prevent them from shifting during transport.

Accessories​

The accessory includes the stock cable, a 6.35mm to 3.5mm adapter, a USB drive, and a warranty card.

Setup​

Can it really be portable? When I plugged the LCD-4z into my portable setup, Cayin N8 black brass + c9, it delivered sufficient sound pressure. In fact, even without the C9, the N8 alone is capable of providing sufficient sound pressure for the LCD-4z, which is very remarkable for a planar magnetic headphone.

However, it doesn't mean LCD4Z doesn't require any power at all. In my experience, planar headphones tend to sound better when fed with "a bit more ". While the N8 can provide sufficient sound pressure, it tends to sound a bit too soft and lacks some dynamics. Adding the c9 resolves this issue perfectly (I'll talk about this later).

Besides, despite its low power requirements, a good DAC is still necessary to fully unleash its potential imo. Therefore, I used two setups for my listening tests: my desktop system with the Linn Selekt as DAC, and a portable setup with the Cayin N8 Brass Black and C9.

Sound​

In Short
The two most notable characteristics of the LCD-4z, in my opinion, are its linearity and neutrality. To be more specific, it is linear, transparent, natural, and detailed. The vocals have just the right thickness and density. The tuning leans slightly towards a warm side, but very very slight, it’s still neutral overall.


Soundstage & Imaging
When it comes to its soundstage, the LCD-4Z continues Audeze's tradition of excellent imaging and soundstage, although it may not rank among the widest soundstages in the realm of open-back headphones, it is decent enough in my opinion.

I was testing the soundstage and imaging with Yosi Horikawa's album "Wandering", I often use this album for testing because of its superb recording quality. In the track "Letter," there's a part where someone is writing with a pencil on a desk, and the effect is incredibly realistic. The first time I heard this album, I actually thought someone was writing right behind me and even turned around to check.


Now, speaking of how does it sounds like on the LCD-4Z. The track "Wandering," with a beginning features the sound of footsteps, as if someone is walking along a muddy road. The image of footsteps is located in the left ear, and then bird chirps and percussion gradually approach from the distant. Just this small segment impressively showcases the LCD-4Z's amazing soundstage and imaging, not only is the image of the footsteps clear and precise, but also the footsteps hitting the muddy ground is vividly reproduced. The percussion at the distant and the bird chirps on the far right are particularly clear, and each sound is precisely positioned.

The overall sense of space feels especially open and natural, giving a feeling of being immersed in the scene. While the LCD-4Z is certainly not the only one capable of achieving such a good imaging, the fact that it can deliver this sound with just a portable setup like the N8+C9 is incredibly valuable.

Resolution
When it comes to resolution, it's essential to use the violin for evaluation. Because, as Paul McGowan mentioned, "Massed strings are some of the most complex musical waveforms I can think of, far more than massed voices. I imagine the spectral content of these hundreds of simultaneously vibrating strings is among the most complex of all and one of the areas where digital audio seems to really struggle with." He explains this in detail in his article on PS Audio’s website, which, I think is very well explained.


Performed by Dinu Lipatti
"Air on the G String" is the track I tested LCD4Z with, and I think this really shows the difference between feeding the LCD-4z with a portable DAC and a full-size DAC. On the N8, the LCD-4z exhibited a gentle quality, with strings sounding very soft. Actually, this Bach piece itself symbolizes calmness and gentleness, embodying a Baroque-era ease. However, when it came to Dvořák's Symphony No. 9, it was time for the desktop setup to shine with abundant information and dynamic. With the Selekt DAC, the LCD-4z presented the string sections with rich detail and sharp dynamics, delivering the grandeur and magnificence of the fourth movement brilliantly. The violin's sound was intricately detailed, with vivid and pronounced dynamics.


Conducted by Claudio Abbado
Moving on to symphony, which is typically a weak point for most portable setup because it require large dynamics. Listening to Beethoven's Symphony No. 7, Allegro the fourth movement, begins with an energetic string section, with high energy and a fast-paced rhythm throughout. The LCD-4z demonstrates decent dynamic while presenting very detailed texture of massed strings.

Treble

Now, let's talk about its highs, which I think are the best part of the 4z. Its treble is linear and smooth, non-intrusive, capable of revealing a lot of vocal high notes and details. When listening to Kuroneko's "Shooting Star," the opening soprano is very smooth and natural. Even with the portable N8+C9 setup, the LCD-4z can clearly separate the background instruments from the vocals. If you close your eyes, you can almost sense the outline of the studio, with instruments arranged in a semi-circle behind the singer. Kuroneko's voice is expressed with great emotion, the thickness is just right, yet it has enough texture and a rich, rolling tail end. The C9 provides excellent control, allowing the soprano to maintain a non-intrusive and non-irritating performance as the pitch rises, which I think is excellent.

Ending​

I didn't structure this article using the traditional divisions of Bass, Mids, and Treble because, to be honest, I prefer using descriptions to recreate the listening experience.

Why

Take an example, when we say "Bassy," it can apply to many headphones like the 64audio Noir, TH900, He1000se etc., but how do we determine which one is "Bassier" than the others? I personally think the answer lies in comparison and description, I believe that it is of great importance to evaluate headphones by describing how they sound with specific songs, and how does it appeal to you.

Moreover, this approach has an advantage. If someone with a similar taste in music comes across this article, it might provide valuable insights. I truly hope this article helps you in deciding whether the LCD-4z is the right choice for you!

Afterword​

I eventually sold my LCD-4z. Despite its easy-to-drive feature, its open-back design made me a walking speaker in the office. So, I had no choice but switched to closed back one: Focal Radiance. If anyone is interested in it, I can write a review of it later

Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs

​

​

4070?​

So, here's the story: I was exchanging headphones with a friend when he suddenly popped the question, ‘are you interested in the 4070?’ Without much thought, I replied, "For sure, why not? " I'd love to overclock my 4060 and turn it into a 4070 if possible, why refusing a REAL 4070 then?

I thought he was talking about the graphics card RTX 4070, even when I noticed a slight smirk on his face, still, I had absolutely no clue what awaited me. A few days later, I received a huge package, inside was indeed the 4070, but the trademark wasn't NVIDIA, it was Stax.


Actually, along with the 4070, there was also a Lambda Pro (Stax SR-Lambda Professional), and this is exactly what this review is about.

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Design Background​

From 1960 to 1982, a span of 20 years, marked the initial phase of electrostatic headphone development. During this period, the bias voltage of electrostatic headphones remained at 230 volts, and the gap between the stators was not particularly wide (0.3mm), while the thickness of the diaphragm (driver) was above 2 micrometres. These parameters largely hindered the improvement of electrostatic sound quality. Later on, around 80s, in response to the request from Mercedes-Benz, the initial professional-grade Lambda Pro headphone was developed for industrial purposes. The Lambda Professional was the first modern electrostatic headphone featuring high bias voltage (580V), wide stator spacing (0.5mm), and an ultra-thin diaphragm (1.5um). Subsequent electrostatic headphones did not undergo such significant improvements in technical parameters.

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Design​

Let's start with the design, the Lambda Pro in my hands exude a sense of ‘age’— or should I say ‘aged’... After all, it was released back in 1982. Assuming this pair is indeed produced in '82, wow, then this year, 2024, marks its 42nd birthday!


Over time, the headband plastic was severely aged and appears to turn white. (Presumably due to crystallization?) I'm a bit worried that one day, if I adjust the headband too forcefully, this old-folk might just snap and be gone for good…


The frame is mainly made of plastic and follows the classic Lambda frame design, which, has even been retained to this day. Although the Lambda series has been discontinued for many years, you can still see this design in today's L700/500/300 series.

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Setup​

Linn Selekt -> Berkeley Alpha DAC Series 2 -> Stax T8000 -> electrostat.

You might be wondering: "Wait, why are there two DAC?"
Well, here's the thing: I sold my Berkeley Alpha USB earlier, and since the Berkeley DAC doesn't support USB input, I found myself in a bit of a pickle. But then, I discovered that the Selekt actually supports SPDIF output, so, I ended up using the Selekt as a USB digital-to-digital converter (DDC).

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Sound​

Its debut note, which also leaves the deepest impression on me, this baby is all about vocal.


Tuning

In my opinion, there's no obvious bias on Lambda Pro, with just a hint of warmth over vocals, but overall, it presents a neutral tone with a balanced tuning, it’s neither warm nor cold. Living up to its ‘Professional’ designation, it tends to lean towards a monitoring-like, straightforward sound signature.


Treble and ‘Tuning Magic’

The Lambda Pro exudes a distinct vintage vibe, with a strong sense of airiness. You'll notice a particularly strong contour and ethereal quality to the vocals, sometimes the imaging might sound slightly forward.

Because of its balanced tuning, the proportion of treble is just right—not overly emphasised, yet not easily overlooked. It exhibits good extension without being overly sharp, resulting in an overall gentle presentation. Additionally, there are no annoying sibilance or hissing issues in the mid-to-high frequencies.

Actually, this is a characteristic tuning from the last century. In principle, high frequencies are most easily absorbed by the air, so the farther away you are, the fewer high frequencies you hear, due to the limited recording capabilities of equipment in the last century, recordings of soprano voices and even some high-frequency instruments were often not ideal (of course, this doesn't mean there were no good recordings in the 80s, but for some smaller studios struggling to survive in the industry, they usually didn't have such good equipment for recording). To bring the vocals closer to the listener and make them feel like the singer is right in front of them (and also to mitigate the impact of high-frequency recording deficiencies), manufacturers used to deliberately boost the high frequencies. However, this habit of tuning has persisted to this day, so even though contemporary high-frequency recording is already quite good, sometimes manufacturers still deliberately boost the high frequencies, resulting in excessive sibilance and stimulation…


Vocal

The vocals of the Lambda Pro largely inherit the tuning magic that was mentioned above imo, the strong sense of airiness combined with the slightly emphasised high frequencies, giving it a rather unique sound signature that stands in stark contrast to most contemporary headphones. On the Lambda Pro, you can ‘feel’ the singer's mouth shape, and it’s like there's a soft aura enveloping the singer. The reproduction of the vocal makes me feel like being right there in front of singer in person, as if I actually saw the intricate mouth movements of her, rather than just listening to a plain recording!


Resolution

Despite the distinctive signature of the vocals, the shortcomings of it are also quite apparent. Although they are all ‘same old’ (released before 2000), Lambda Pro doesn’t have as good resolution as Sennheiser's 580 Jubilee or Sony R10. The resolution of the Lambda Pro tends to be more subtle, with a preference for softer imaging rather than highly intricate details and clear imaging. The issue in resolution becomes more pronounced when reproducing orchestral pieces, especially those involves multiple instrumental sections and a large number of instrumental performers, in rare cases, the positioning of instruments sound not sufficiently precise.

But hey, wait! Don't get me wrong, I mean, there's probably not much need to overly criticise the resolution of a headphone from 40 years ago with a modern perspective


Soundstage

Actually, its soundstage could be better, but it's constrained by the technology available at the time. The Lambda Pro's drawback lies in its relatively small driver (diaphragm) size (especially when compared to Omega series) and shallow earcup design. In most cases, the soundstage remains brilliant, with a decent horizontal soundstage that inherits the advantages of open-back headphones: natural; and there's no apparent sense of boundaries constraining you.


Bass

While the Lambda Professional doesn't suffer from the rumoured ‘bass deficiency’, the bass of the Lambda Pro is actually appreciable in quantity, but it could be improved in depth, layer and sub-bass reproduction.


The Lambda Pro does offer a commendable amount of bass, even to the point of being quite generous for a electrostatic headphone. However, it would be better if the bass could go deeper than the mid-bass. Part of issue in bass might stem from the design of the earcups imo. Firstly, they are too shallow to create a channel for bass to reflect inside. The shallow ear cups also lead to another problem: the drivers press directly against the ears, causing discomfort when worn for long periods of time, besides, it also results in poor sealing against the face, leading to bass leakage.

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In summary, I find the sound of the Lambda Professional to be quite intriguing. As the first attempt from Stax to adopt the Pro bias (580v), it presents a strikingly different, straightforward sound signature compared to today's Lambda series. Even 40 years later, its sound remains remarkably engaging.

Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs

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Intro.​

Similar yet different
As a portable player featuring vacuum tubes, the N8ii, as the successor to the N8, shares some similarities while also introducing some differences.

Similarities include the use of KORG vacuum tubes, but this time, there are two, as it implements balanced tube amplification. However, unlike the rich and warm tube sound of the N8, the N8ii's tube mode tuning approach is surprisingly closer to the C9 rather than the N8, offering a more neutral and accurate sound. The N8 first generation is noticeably warmer in tonality, partly due to the AKM4497 chip, while the N8ii this time employs Rohm's BD34301EKV. The new circuit architecture brings about a different tuning, making the N8ii sound cleaner, clearer, and more direct.


In addition, the iconic golden triangle smiley face was abandoned to accommodate the touchscreen. This makes it less 'characteristic' compared to the previous generation. However, if I were to choose, honestly, I think I would still prefer the touchscreen because of its practicality.

Switching to a healthier diet?
The N8ii aims for transparency and neutrality, with a slight warmth in tuning. Some believe this symbolises the 'loss of spirit of vacuum tubes,' which is also one of the controversial points about the N8ii.

In my opinion, the 'flavour' in the N8ii's tube mode is indeed reduced compared to the N8, but the rest were significantly improved. The N8ii's tube mode becomes more delicate, more detailed, striking a good balance between sound flavour, resolution, and dynamics.

Its flavour is akin to adopting a healthier diet, becoming much milder. This is a point that can be seen as either good or bad, depending on personal preference.

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Settings
The settings I used for review: Solid-state, Class AB , P power mode.
And I used the 64 Audio Noir and tia forte, as well as a LCD-4z for review.

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Sound​

Class A/AB
When it comes to the Class A/AB mode, it's the first noteworthy feature of the N8ii, the newly designed switchable Class A/AB amplification circuit. The entire amplification circuit delivers astonishing dynamics and detail in AB amplification mode; however, in Class A amplification mode, there's a slight loss in dynamic, especially noticeable in concerto, symphony, and rock tracks that require large dynamic swings. Nonetheless, the difference is less distinct in pop and vocal performances.

Bass
Firstly, the bass is finely tuned, exceptionally clean and cohesive, with moderate weight and energy concentrated at mid bass. There's noticeable elasticity without a sluggish rebound thanks to its fast speed. In the tube mode, the bass is slightly softer, slower, with less emphasis on texture and impact, and a slightly reduce in quantity compared to the solid-state mode.

Overall, it's a bass that's impactful, with excellent depth and emphasis on texture and rebound speed. I really appreciate this balance because it's just right, if it were to emphasise bass impact a bit more, it might appear too dry and hard.

Vocal
The vocals are also finely tuned for transparency, without any obvious bias. They exhibit high density with moderate thickness, emphasizing clarity in articulation and precise positioning of vocal sources. Additionally, unlike the previous generation N8, which tended to soften vocals, the N8ii doesn't apply too much smoothing to vocals. Sibilance doesn't disappear completely, aiming to preserve the natural texture of female vocals, again, this is a point that can be seen as either good or bad, depending on personal preference.

As a result, vocals sound clear and bright without being overly stimulating, demonstrating a well-balanced tuning.

Treble
Then onto the treble. Clean, natural, and transparent, with smooth and excellent extension. Though clean, it doesn't appear palm; though extends quite high, you don't feel harshness or fatigue; the treble is well refined.

In the tube mode, the imaging of vocals is brighter and clearer. And speak of brightness, in my opinion, it is moderate on N8ii, it doesn't artificially enhance the highs to make it sounds 'brighter', instead, the N8ii maintained smoothness while emphasised the good extension. The appropriate brightness also ensures listenability, I mean, you won't feel fatigued even when paired with iem with a rather offensive treble like the tia forte, of which has a quite offensive treble peak and could appear a bit too bright sometimes. However, on N8ii, the highs of the tia forte is well controlled in various scenarios.

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Personally, I prefer using the tube with the P+ power mode for solo or sonata pieces. Although it may not deliver the same level of resolution as the solid-state mode, the overall performance of instruments, including the layered bass of drums and the airiness of string instruments, are just excellent. Another suitable direction for the N8ii is metal rock, in the tube mode, the bass remain tight and clean. Additionally, the brightness, clarity, and energy of the treble are better than solid-state mode imo.

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Could be better?
Actually, there are two points I feel could be improved.

Firstly, the thickness. The N82's thickness reaches 2.5cm, and I don't know whether or not your pants have pockets that big, but at least mine don't. I remember years ago when Sony dominated the portable DAP market, I bought a ZX2, slipping it into my pocket and putting on a pair of headphones to wander around was a distant yet beautiful memory.
But today, it's hard to say that portable players can still be described as "portable".

Secondly, speaking of pocketing it, there's another issue: heat. If you're running the tube mode, Class A amplification, at P+ mode, and then use it in a non-ventilated environment like inside your pocket, what you'll probably get is a device that's really hot. Sometimes, when I use it as a desktop DAC/amp in my office, opting for USB input while powering it, it also generates a considerable amount of heat. Under certain circumstances, it may overheat, triggering protection mode and stopping the charging process.

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Epilogue​

The N8ii tube mode indeed sounds more like what you'd expect from a solid-state mode. Well it's like in the era of film cameras, we would commend a photographer's skill by saying, "It's so clear as if you shot it with a digital camera."

In conclusion, the N8ii does indeed has a much lighter flavour compared to the N8. But if we set aside the inherent impression of the warm tuning of the N8, we would find the sound becomes more mellow, delicate, and airy. This fresh tuning really strikes a fine balance between the accuracy and pleasing of the tube sound.

Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs

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Prelude​

When it comes to the TH909, most discussions revolve around two main points:
1: whether the 909 is an upgraded or even "ultimate" version of the 900;
2: whether the sound of the TH909 is much more neutral than the TH900; or even to the extent that it loses some of the distinct characteristics of the TH900.

Regarding the first topic, personally, I don't consider the 909 to be a true "upgrade" or "ultimate" version, because the drivers in the 909 are very similar to those in the th900s. I believe Fostex has mainly made some tuning adjustments, similar to what they did with the Blue 900, White 900, and Purple 900 versions (the Green 900 essentially being a repainted TH900 mk2 Red); or perhaps they've made very minor tweaks.

Driver of TH909

Although marketed as open-back, the TH909 doesn't quite resemble typical open-back headphones, as you can't see the drivers from the outside.
Upon disassembling the TH909, I discovered a dual-layer acoustic material behind the waffle-like outer structure, isolating the drivers from the outside. The first layer consists of black high-density foam (underneath the white bio cellulose film), topped with a layer of white Bio cellulose film (similar to the paper-like film on the driver).
From this perspective, I don't really consider the TH909 to be an fully opened-back headphone.

Sound​

Tuning

The TH909 has indeed, 'compromised' a lot compared to the TH900, TH909 didn't inherit the iconic V-shaped tuning of TH900 series. It leans more towards a neutral and balanced tuning style, although objectively speaking, it's not entirely neutral.

I once owned a TH900 MK1 Red, and I believe it has an issue with the midrange: mids is quite thin, with imaging positioned towards the rear; on this basis, the V-shaped tuning is like pushing the mids way behind the bass and treble, which further encroaches on the mids' existence.

The tuning of the TH909 is like dulling both ends — the highs are no longer piercingly bright, and the lows are no longer overwhelmingly powerful. Though the sound signature remains similar to the TH900, the tuning sets them apart as two distinct headphones. It's like a bottle of aged whisky—no longer harsh and spicy, but rather composed.

The TH909's standout characteristic lies in its departure from the legacy V-shape tuning of the TH900 family.

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Soundstage

I think the TH909 and TH900 don't show very significant changes in terms of soundstage; they both have brilliant soundstage with ample spaciousness. Both of them have brilliant horizontal soundstage that is wide enough to precisely demonstrate the separation of instruments, you can distinctly and clearly sense the instrumental placements, with sufficient spacing between each instrument.

I believe the difference between the soundstages of the TH909 and TH900 lies in the vertical dimension. The TH909 exhibits better vertical soundstage, allowing you to perceive more differences in the layout of instruments in depth.

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Bass

The bass of the TH909 is no longer aggressive and fierce but appear more 'civilised'.

Bass texture of the 909 is similar to TH900's, with good extension, different layers and decent impact. However, the depth of the bass isn't as deep as TH900 imo, the sub-bass doesn't goes as deep as the TH900. With the TH900, the overwhelming bass always drew all of my attention when listening to EDM tracks, I mean, that cool, that's the point I like TH900 so much, the depth of TH900's bass is like a ’Journey to the Center of the Earth', both energetic and stunning.

One of my favourite EM: Enough Is Enough (feat. Richard Caddock) - Puppet & Cormak

In contrast, the TH909 tends to remind you that 'this part is the bass, and that's it', without drawing your entire attention away . It lacks the TH900's striking bass impact, not that punchy.

Overall, the bass on TH909 has a more cohesive characteristic, especially when listening to rock tracks, the performance of the TH909 is more like the drummer's beats complementing the band's performance, while the TH900 is like the drummer has ‘knocked out all the other members' and then taking the opportunity to pound vigorously on stage.

Speaking of rock, I highly recommend this one: Come Close - Saosin

In summary, while traces of the TH900's bass characteristics can still be found, there's a noticeable difference in impact and depth.

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Mids/Vocal


The vocals have now reached a completely acceptable level. Although there hasn't been a significant increase in mids thickness, the vocal imaging distance has been pushed forward a lot, and, most importantly, thanks to the balanced tuning without peaks at both high and low ends, vocals can now be heard more clearly.

So, with all these improvements combined, vocals have become much more natural. Furthermore, they've become very smooth, without any piercing or harshness at the peak of vocals, although under some circumstances there might be sibilance, it's not overly jarring. Listening to anime tracks won't feel like the highs are piercing your eardrums, and vocals won't sound like they're coming from a distance. It truly provides an enjoyable vocals.

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Highs/Treble

When listening to the TH900 previously, I sometimes felt that the treble was way too bright and sharp, to the point where my ears would even ring after taking off the headphone. But now on the TH909, the energy in the treble has returned to a more normal level. It's no longer like a wild horse running unrestrained, reaching to endless high. The tuning of the TH909 is like taming that wild horse, it largely resolves the issue of piercing and uncontrollable treble.

Since the problem of sharpness is no longer present, the remaining issue is sibilance. Sibilance only occurs in a few instances, perhaps only about 1/6 as much as with the TH900, which is within an acceptable degree.

However, in terms of brightness, if you're accustomed to the bright sound of the TH900, you may feel that the TH909 has lost some of its brightness and appears somewhat dimmer. This feeling is akin to painting a light gray coat over a bright white light bulb, resulting in an overall decrease in brightness and a sense of dimness.

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Epilogue​

Overall, the TH909 makes me feel like it's a product of compromise, a concessions to the market in order to appeal to a wider audience, it's leaning more towards balance though in fact it's not entirely balanced as neutral.
For me, its benefit lies in saving me the trouble and expense of buying mod kits one by one to try out the effect. It achieves a non-fatiguing sound with smooth and forward vocal imaging. However, my biggest regret is that the bass and sub-bass are no longer as impactful and deep as the TH900. If it could retain the bass punchy while achieving this sound signature, I believe I would be absolutely satisfied.

Disclaimer: This review has no commercial intent; but simply to document the sound of the TH909, a distinctive member of the Fostex family that I greatly adore.

Welcome to my review! I write reviews to document the interesting headphones I've tried;
As time may pass, headphones may break, but knowledge can be passed down forever!
——Brandfuchs



Disclaimer: This one is not a tour unit, I purchased it. I didn't participated the tour because HFM didn't organise it here in China..

The purchase of the Jade II came about when I decided to take a break from the dynamics headphones, I tried a lot of them back then, various colours of TH900, HD800/s, Denon's D7000 series, etc.,
I was thinking, ‘why not try something else? like electrostatic headphones?’
Coincidentally, I stumbled upon an alluring priced STAX T8000, so I grabbed the bargain and started my electrostatic journey.
However, I still needed a pair of electrostatic headphones to complete the system. Initially eyeing the L300LTD, yet I couldn't find one at the reasonable price. So, I turned to a local dealer and bought a Jade 2 instead.
So basically, I didn't buy the officially matched Jade II Amplifier because, well obviously, I had better ones; besides, my friend told me that the official ones can't really drive it very well...

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Setup
Linn Selekt Organik→STAX T8000

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Back to the topic
I'd like to start with an introduction to the Appearance first
I don't know if you'd call it that in your neck of the woods, but in China, whenever the Jade 2 is mentioned, people tend to use another word to describe it: fly's eye (because of the mesh grille and the gradient purple-green color)

In fact, fly-eye green is a rather deprecating description, there are way-better words to describe this kind of green. I personally have a strong fondness for the green tone of the Jade II's driver. It embodies the verdant hues that could be found in the lush foliage of the forest——
It's like a glimmer of morning light weaves through the towering trees and dense canopies, creating dappled, deep, and saturated green. This is what Jade 2 looks like to me.

Although the current stealth version of he1000 v2 and arya have been coated with a film of the same green colour, the jade2 looks much more impressive with such a complete and LARGE verdant driver.

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Design
Though the black matte finish of the Jade2 frame looks very metallic at first glance, it's actually made of plastic. The frame is made of plastic as is the driver hanger making it kinda feel like a cheap plastic toy when you hold it in your hand...

By the way, the angle of the driver is fixed and not adjustable... which, I do really think should be improved

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Sound impression:
Overall tuning
The tuning of the Jade 2 is quite balanced, without any apparent bias.
The overall style is slightly bright, but as I mentioned above, its three-frequency distribution is very balanced, so it won't make the vocals sound particularly bright or any part of instrument feels very bright.

Vocal
The vocal of the Jade2 is as neutral as its overall tuning, very neutral without any obvious seasoning, maybe slightly leaning towards cool but not to the point of being cold or unpleasantly harshness. The transition between the mid and high frequencies is very smooth. Perhaps different from most users here, the tracks I listen to most often are anime tracks. During the audition, I chose the song "Aiobahn - resonance (ft. KOCHO)." In this song, the transition of the Aiobahn's voice from low to high tones is very smooth, and such natural transition and crystalline clear vocals are the two main reasons why I like electrostatic headphones.

Resolution
As for the resolution/instrument separation, although the Jade 2 has a rather 'decent' resolution, it doesn't seem to emphasise it much; instead, it presents the vocal and instrument more softly. Jade 2 doesn't much emphasise the separation between instruments to make the spacing between each instrument distinctly noticeable, the boundaries between instruments are not very sharp; instead, sometimes, the boundary sense of instruments on the Jade 2 is slightly blurred, or should I say 'soft'?
Interestingly, my TH900 was quite the opposite in this aspect; the TH900 violently separated details, making it possible to clearly distinguish the contours and boundaries of each instrument.

Points I think could be improved
Bass
As a basshead, I feel there is room for improvement in the bass of the Jade 2. Of course, the bass of the Jade 2 are by no means deficient or incomplete; the lower midrange is sufficiently full, ensuring adequate vocal density without sounding hollow. Overall, the issue with the bass lies in its lack of 'existency'. Sometimes, there is insufficient impact, making it feels weak and somewhat insubstantial. Besides, there could be more low rumbles to create a sense of atmosphere, but that's also what Jade 2 in lack of I think.

Highs
If the high frequencies were raised slightly further, the Jade 2 would likely achieve the airy quality characteristic of STAX headphones: that sense of sound freely flowing on stage, as if you were immersed in a vast theatre.

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In summary, I think the Jade 2 is pretty good.
Of course, if the headband frame could be replaced with metal, the hanger designed to be adjustable in angle, and the cables made replaceable, that would be perfect.