The KSE1500 in-ear electrostatic earphone was a breakthrough product 3 years ago and occupies a top spot in the high end in-earphones market then.
With the recent trend of price increase in the flagship iems (think obravo, vision ears, spiral ear) it might not occupy the top spot price wise but nothing has changed when you compare its performance and unique technology against these flagships.
A new iteration, KSE1200 was introduced in 2018, which simplified the accompanying dac amp system by removing the dac component and comes with a 1/3 price reduction.
Packaging and build
Pretty decent, each part is placed in well-organized compartments, surrounding good protection.
Accessories include the following:
KSE1500 headphones
KSE1200 amplifier,
two 3.5 mm interconnect cables of 15.2 cm and 92 cm
6.3 mm adapter
headphone clip
2 straps
These earbuds are lightweight with an oval compact design that should fit well in the ear canal of average user. While its housing made of a transparent material (plastic?) does not really inspire much confidence in its durability. Overall I would consider the design pretty ergonomic and i experience no discomfort in my ear canal with long-term listening compared to most other iems.
Design
Most earphones in the market utilize 2 type of drivers, balanced armature or dynamic (voice coil) for reproduction of sound. These designs are easier to miniaturize for portable use and you can fit multiple drivers (eg 18 drivers in 64audio's U18t) into a earpiece. However, balanced armature designs are susceptible to distortion and noise due to crossovers from multiple drivers and phase shift etc. While dynamic drivers can cover broad ranges, they have less detail and speed compared to balanced armature counterparts.
The principle of an electrostatic technology is relatively more complicated. It makes use of an electrostatic field composed of two conductive back plates and a diaphragm. The diaphragm centered between the electrostatic field is guided to vibrate by applying a charge between the conductive back plates. In theory, the directly transmission of applied electric energy signal into sound waves will result in audio with a high correlation to the original signal resulting in a more realistic presentation throughout the entire frequency range.
What makes KSE1500/1200 a standout is that they feature a miniaturized form of this technology and is equipped with an ultra-light charged diaphragm suspended inches apart from the two conductive back plates surrounded by an electrostatic field. Because the diaphragm is extremely thin, it can be polarized by high DC voltage to vibrate rapidly and output high-fidelity audio.
Another aspect of its design is its sound Isolating properties of up to 37 dB of ambient noise when fitted properly in the ear canal which is on par or better than custom iem.
The earphones are attached to a special custom designed cable made from Kevlar that provides the isolation in each line for optimal transmission of signals from its headphone dedicated amplifier which you are pretty much confined to.
The main difference between the KSE1200 and the KSE1500 is that the KSE1500 system is equipped with a DAC and extra eq options, while the KSE1200 is designed as a pure analog headphone amplifier.
This means one has to use a DAP with a 3.5mm output for connection to transmit signal for playback with the KSE1200 amp. You can use the output from your phone but given the wide variety of DAPs available there really is no reason to do so.
Sound impressions
Listening is done mostly via output from Cayin n3 for portability. There is an upgrade in sound quality when I switch to Hugo2 but i find its not worth the trouble as the improvement is not as significant compared to my other iems.
In general, KSE1200 has a well balanced neutral signature where no frequency is overly emphasized. Music is clear and pristine and every intricate detail is brought forward with its sheer resolving power. These really give me the impression that i am listening to music in a recording studio.
Soundstage
The soundstage dimension is average, with about equal depth and width, though the height is excellent as expected with its strong treble performance.
Bass
Some people consider the bass as its weakest area, due to its neutral setting with a lack of coloration. If you are a basshead, these are not going to satisfy you compared to a powerful bass of a dynamic driver But if you look at it from a reference perspective, they do pretty well in terms of quantity and balance.
Percussion instruments are taunt and impactful with a slight subbass emphasis and ends with proper reverberation. Bass line contours are well defined while remaining clean with no bleeding. The most impressive aspect of the bass is the accuracy of its transient and precision of its timing which provides a well organised performance.
Mids
The noise isolation properties of KSE together with a dark background from low distortion greatly benefits vocal performance. Once again mid signature are neutral in positioning and relatively colorless. There is no audible distortion or vocal coloration (nasal, chesty, boxy) in the mids which are quite prevalent in many BA iems. The emphasis is on vocal articulation rather than depth and power, so if there is sibilance in a track, you will hear it. Personally, I wouldn't classify these mids as musical or emotional but they do have a pure and sometimes raw quality that you dont hear often as a result of its transparency and resolving power.
Treble
Treble seems to be the slightly more prominent frequency but it never spits hot. Instruments such as high hats,chimes are rich with details and spatial cues. These highs seem to penetrate every nook and cranny in the recording to reveal all the micro details in the music. Transients are crisp with no spikiness and has an agility BA iems cannot match. All in all, this is a revealing treble I can enjoy with minimal fatigue.
Comparison
With the advent of new iems utilizing elctrostatic technology how does the old dog compare to the new kids on the bloc?
Jomo trinity stainless steel
Sound stage is wider and deeper in the jomo model but i find the background darker with kse. The trademarks of its dynamic driver for bass are there with a more powerful and weighted rumble, but the bass does not have the precision and definition of kse especially with faster percussion tracks. Mids is where I find the most difference while both have good resolution and detail, trinity sound more dished/hollow compared with kse and not as coherent. Treblewise, kse presents more detail and speed in its transients while trinty ops for a more controlled and grounded treble that has good detail retrieval as well but is not as revealing.
Fitear EST
Fitear is the first company to adopt electrostats from sonion in their products. Soundstage width feels relatively similar, though depth and height is more with kse. Its signature is warm with an emphasis in its midrange which is more emotional. I would not have guessed that it contains an electrostat driver based on the smooth treble tuning. Both treble/bass detail retrival and speed falls behind kse, but its mids have good linearity with more body and warmness which i feel express emotions in music better compared with kse.
Pola
I tried them sometime ago, so these impression might not be acurrate. Bass from its 13MM Graphene dynamic driver has good impact and is pretty clean, though not alot of extension or rumble. The mids more forward and warm with slightly more body, though i hear a dip in the uppermids. The treble notes produced from its tweeter hits hard and fast in their transients with relatively good extension but its tonality is too sharp to sound accurate compared with kse.
AAW canary
Canary boasts a wider and deeper soundstage with a dark background and excellent imaging. Its isobaric subwoofer produces a deeper bass rumble that spreads more naturally compared to typical dynamic drivers which are more concentrated in impact. However its hits are not as defined or precise as KSE. Mids are warm with more body and forwardness, though not as linear with an upper mids dip. Its treble has a darker tilt, not as airy or having much sparkle. Overall quite different when compared with kse.
Verdict
The new KSE1200 brings the top performance of KSE1500 to a wider audience with its relatively more affordable pricing. It might not sound musical or emotional with its colorless signature that take some getting used to, but on the upside it boast an uncanny ability to transit between different genres with ease and just reveal the music as it truly is.
With the recent trend of price increase in the flagship iems (think obravo, vision ears, spiral ear) it might not occupy the top spot price wise but nothing has changed when you compare its performance and unique technology against these flagships.
A new iteration, KSE1200 was introduced in 2018, which simplified the accompanying dac amp system by removing the dac component and comes with a 1/3 price reduction.
Packaging and build
Pretty decent, each part is placed in well-organized compartments, surrounding good protection.
Accessories include the following:
KSE1500 headphones
KSE1200 amplifier,
two 3.5 mm interconnect cables of 15.2 cm and 92 cm
6.3 mm adapter
headphone clip
2 straps
These earbuds are lightweight with an oval compact design that should fit well in the ear canal of average user. While its housing made of a transparent material (plastic?) does not really inspire much confidence in its durability. Overall I would consider the design pretty ergonomic and i experience no discomfort in my ear canal with long-term listening compared to most other iems.
Design
Most earphones in the market utilize 2 type of drivers, balanced armature or dynamic (voice coil) for reproduction of sound. These designs are easier to miniaturize for portable use and you can fit multiple drivers (eg 18 drivers in 64audio's U18t) into a earpiece. However, balanced armature designs are susceptible to distortion and noise due to crossovers from multiple drivers and phase shift etc. While dynamic drivers can cover broad ranges, they have less detail and speed compared to balanced armature counterparts.
The principle of an electrostatic technology is relatively more complicated. It makes use of an electrostatic field composed of two conductive back plates and a diaphragm. The diaphragm centered between the electrostatic field is guided to vibrate by applying a charge between the conductive back plates. In theory, the directly transmission of applied electric energy signal into sound waves will result in audio with a high correlation to the original signal resulting in a more realistic presentation throughout the entire frequency range.
What makes KSE1500/1200 a standout is that they feature a miniaturized form of this technology and is equipped with an ultra-light charged diaphragm suspended inches apart from the two conductive back plates surrounded by an electrostatic field. Because the diaphragm is extremely thin, it can be polarized by high DC voltage to vibrate rapidly and output high-fidelity audio.
Another aspect of its design is its sound Isolating properties of up to 37 dB of ambient noise when fitted properly in the ear canal which is on par or better than custom iem.
The earphones are attached to a special custom designed cable made from Kevlar that provides the isolation in each line for optimal transmission of signals from its headphone dedicated amplifier which you are pretty much confined to.
The main difference between the KSE1200 and the KSE1500 is that the KSE1500 system is equipped with a DAC and extra eq options, while the KSE1200 is designed as a pure analog headphone amplifier.
This means one has to use a DAP with a 3.5mm output for connection to transmit signal for playback with the KSE1200 amp. You can use the output from your phone but given the wide variety of DAPs available there really is no reason to do so.
Sound impressions
Listening is done mostly via output from Cayin n3 for portability. There is an upgrade in sound quality when I switch to Hugo2 but i find its not worth the trouble as the improvement is not as significant compared to my other iems.
In general, KSE1200 has a well balanced neutral signature where no frequency is overly emphasized. Music is clear and pristine and every intricate detail is brought forward with its sheer resolving power. These really give me the impression that i am listening to music in a recording studio.
Soundstage
The soundstage dimension is average, with about equal depth and width, though the height is excellent as expected with its strong treble performance.
Bass
Some people consider the bass as its weakest area, due to its neutral setting with a lack of coloration. If you are a basshead, these are not going to satisfy you compared to a powerful bass of a dynamic driver But if you look at it from a reference perspective, they do pretty well in terms of quantity and balance.
Percussion instruments are taunt and impactful with a slight subbass emphasis and ends with proper reverberation. Bass line contours are well defined while remaining clean with no bleeding. The most impressive aspect of the bass is the accuracy of its transient and precision of its timing which provides a well organised performance.
Mids
The noise isolation properties of KSE together with a dark background from low distortion greatly benefits vocal performance. Once again mid signature are neutral in positioning and relatively colorless. There is no audible distortion or vocal coloration (nasal, chesty, boxy) in the mids which are quite prevalent in many BA iems. The emphasis is on vocal articulation rather than depth and power, so if there is sibilance in a track, you will hear it. Personally, I wouldn't classify these mids as musical or emotional but they do have a pure and sometimes raw quality that you dont hear often as a result of its transparency and resolving power.
Treble
Treble seems to be the slightly more prominent frequency but it never spits hot. Instruments such as high hats,chimes are rich with details and spatial cues. These highs seem to penetrate every nook and cranny in the recording to reveal all the micro details in the music. Transients are crisp with no spikiness and has an agility BA iems cannot match. All in all, this is a revealing treble I can enjoy with minimal fatigue.
Comparison
With the advent of new iems utilizing elctrostatic technology how does the old dog compare to the new kids on the bloc?
Jomo trinity stainless steel
Sound stage is wider and deeper in the jomo model but i find the background darker with kse. The trademarks of its dynamic driver for bass are there with a more powerful and weighted rumble, but the bass does not have the precision and definition of kse especially with faster percussion tracks. Mids is where I find the most difference while both have good resolution and detail, trinity sound more dished/hollow compared with kse and not as coherent. Treblewise, kse presents more detail and speed in its transients while trinty ops for a more controlled and grounded treble that has good detail retrieval as well but is not as revealing.
Fitear EST
Fitear is the first company to adopt electrostats from sonion in their products. Soundstage width feels relatively similar, though depth and height is more with kse. Its signature is warm with an emphasis in its midrange which is more emotional. I would not have guessed that it contains an electrostat driver based on the smooth treble tuning. Both treble/bass detail retrival and speed falls behind kse, but its mids have good linearity with more body and warmness which i feel express emotions in music better compared with kse.
Pola
I tried them sometime ago, so these impression might not be acurrate. Bass from its 13MM Graphene dynamic driver has good impact and is pretty clean, though not alot of extension or rumble. The mids more forward and warm with slightly more body, though i hear a dip in the uppermids. The treble notes produced from its tweeter hits hard and fast in their transients with relatively good extension but its tonality is too sharp to sound accurate compared with kse.
AAW canary
Canary boasts a wider and deeper soundstage with a dark background and excellent imaging. Its isobaric subwoofer produces a deeper bass rumble that spreads more naturally compared to typical dynamic drivers which are more concentrated in impact. However its hits are not as defined or precise as KSE. Mids are warm with more body and forwardness, though not as linear with an upper mids dip. Its treble has a darker tilt, not as airy or having much sparkle. Overall quite different when compared with kse.
Verdict
The new KSE1200 brings the top performance of KSE1500 to a wider audience with its relatively more affordable pricing. It might not sound musical or emotional with its colorless signature that take some getting used to, but on the upside it boast an uncanny ability to transit between different genres with ease and just reveal the music as it truly is.
I find the KSE 1200 mind-bendingly musical. For a start you can follow any instrument (or sound) clearly within the mix. That alone is a feat in itself given the KSE 1200 is an IEM soundstage. Then each instrument has stunning tonality and timbre.
There are times when I think I am not in the mood for them. However there are times when I am not in the mood for my main system. This again however, is something else. It is in these instances that I have usually chosen the wrong music for my mood. Any system can sound annoying at those times. Or maybe I would rather be watching something or playing a video game.
The KSE 1200 on their own, are a gift of purity and beauty. Albeit a not inexpensive one. Anyway that's my honest opinion. I respect yours also.