Zerest Audio: Kagami Wireless
- Added by Vanillacones
- Create date
Introduction
Zerest Audio is an audio startup from Singapore who just recently released their second major product, the Kagami Wireless earbuds, after their successful funding on Kickstarter. As a local backer, I figured I would do a review to help gain this company a little more publicity and help guide prospective buyers if these wireless earbuds are right for them. I received the “Midnight” colour version of the earbuds, which set me back SGD$109 (~USD$82), which was the Kickstarter early bird price at the time. Their MSRP is SGD$149 (~USD$112) on their Shopee store.
Their first products, the Kagami and Kagami+, were handmade wired IEMs with a warm V-shaped sound signature. Reviews for them are already on HeadFi, though do note that they are discontinued.
I used a Samsung Galaxy S23 Ultra via Bluetooth (AAC is as good as it gets) as my source, with a mix of locally stored MP3, FLAC, M4A, and WAV files for listening to music. Now on to the review.
Unboxing, Build Quality, and Comfort
The Kagami Wireless earbuds come in a higher quality box than their predecessor, which was handmade. This makes sense, since the Kagami Wireless are mass produced while the Kagami IEMs were entirely handmade, from box to product.
Inside are the earbuds, case, and documentation, along with a small black box containing its accessories. It includes a USB Type A to C cable, small suede-like pouch, and two different-sized pairs of ear tips (not pictured because I misplaced it, whoops).
A small gripe I have with the case design is that it easily topples over without the earbuds due to the weight of the cover.
As for comfort, these press-fit snugly into my ears. Of course, your mileage may vary. It seals well for me, which means that there’s good passive noise isolation from the outside and should help with bass extension. The fit is secure and comfortable, especially with its extremely light weight. In fact, these may be one of the most comfortable earbuds I ever wore! Zerest Audio definitely deserves some commendation for tackling ergonomics quite well.
Usability
Using it off and on for a few months now, connectivity between the earbuds and my phone is unfortunately sub-par. Dropouts aren’t uncommon, with audio randomly cutting out while walking or just handling my phone out of my pocket before normally reconnecting. I’m not sure if it’s just my particular set that’s exhibiting issues, but I haven’t seen similar complaints from other reviews.
On that note, let’s talk about the touch controls. They feel generally unresponsive, with quick, successive taps to adjust volume sometimes not registering, and having to wait almost 2 seconds for music to pause or resume after a single tap. I’ve resorted to just adjusting volume and changing tracks on my phone instead. This is certainly an area where I feel Zerest Audio can improve on.
Sound Quality
I’d say sound quality is the Kagami Wireless’ strongest point. To start off, the following graph is the frequency response measurements provided by Zerest Audio themselves, from a Kickstarter backer Q&A:
Weirdly they didn’t provide the x or y axes of the graph, so it’s difficult to quantify what the line objectively represents. Assuming it’s a raw FR graph, we can only surmise a bass boost and some treble dips past the upper mids. I can at least corroborate that it is somewhat accurate during my listening sessions (keeping in mind confirmation bias of course).
Regardless, to me, the bass sounds loose and boomy rather than tight and snappy. The attack of the dynamic driver in these frequencies sounds blunted and its decay exaggerated, especially in bass-heavy tracks. The difference in transducer speed becomes apparent when comparing it to my Moondrop Blessing 2 and only widens against the Etymotic ER3SE. Disappointing for sure, but not a total dealbreaker.
Additionally, while the bass boost is mostly constrained to 300Hz and below, the bass quantity could easily make the bass in crowded tracks seem overpowering and even bloated. Though if you’re a basshead, you’ll probably enjoy the thunderous bass these earbuds have to offer. Zerest Audio markets this product as “made by audiophiles for consumers”, and that really resounds here.
I perceive the Kagami Wireless’ lower midrange to be more or less neutral, with most instruments in this frequency range sounding balanced and natural. The upper midrange and treble frequencies, however, would be what I call the earbud’s Achilles’ heel. Female vocals lack air and breathiness, and while male vocals sound generally warm and natural enough, higher-pitched singers don’t sound as full. All this coupled with a boost in the vocal frequencies to balance out the heavy bass boost makes the tuning sound harsh and shouty in certain tracks.
Dips in the treble region underemphasizes crashing cymbals, high-hats, and other high-frequency instruments, causing a “bit-crushed”, low-resolution like sound, despite listening to high-quality music files. This is most noticeable in busy genres such as metal and rock and will probably bother metalheads like myself. On the other hand, I don’t think the recessed treble is something that a lot of people would notice immediately, unless you have a neutral reference to compare with.
All in all, I’d say that the Kagami Wireless sports a warm-leaning, bass-heavy and vocal-centric sound signature, though I wouldn’t fault critical listeners for calling it dark due to the sheer bass quantity and dips in the treble.
Equalisation
To smoothen the treble, restrain the bass, and overall make the earbuds sound more neutral, I used the following parametric EQ profile:
Preamp: -4.5 dB
Filter 1 (Peak): 60 Hz Gain -9.0 dB Q 0.250
Filter 2 (Peak): 4500 Hz Gain -6.0 dB Q 2.00
Filter 3 (Peak): 8000 Hz Gain 2.0 dB Q 4.000
Filter 4 (High Shelf): 8000 Hz Gain 4.5 dB Q 0.700
Filter 5 (Peak): 10500 Hz Gain -4.5 dB Q 3.000
The first filter adjusts the bass. Personally, the seal and fit of the earbuds is so good that despite reducing the bass by a whopping 9 dB, it still managed to retain enough punchiness and rumble to be enjoyable. Or maybe that’s just another testament of how much bass they come with out of the box. Feel free to adjust the gain according to your own taste.
The rest of the filters basically lowers the harsh upper mids to be more bearable whilst elevating the treble to restore that lost detail. With this EQ profile, I find the Kagami Wireless more enjoyable and listenable to over longer periods of time.
Soundstage & Imaging
The soundstage of the Kagami Wireless earbuds is decently wide but lacking height and depth, resulting in a flat and two-dimensional stage. In the realm of wireless in-ear buds though, especially at this price, these are completely fine and serviceable.
As for imaging, these are average for in-ears at this price too. Instruments and objects are placed in generally 3 “blobs”; left, right, and center. In part due to its soundstage, instrumental separation suffers, so they don’t sound the most defined nor precise. There is some amount of layering to be heard, but only if the track allows it.
Conclusion
With all my criticism with its bass and treble, at SGD$149 (~USD$112), I still think that the Kagami Wireless is a decent buy for those looking for a “bass cannon” experience. It’s neither a value king at that price, nor is its sound quality so unpleasant to merit disapproval.
Consumers will likely enjoy the bass boost provided without vocals sounding wonky or being heavily smeared, like one would hear in most cheaper consumer wireless earbuds. Audiophiles, on the other hand, may find its bass overpowering and treble lacking. For bassheads though, I still think it’s worth considering in its price range.
P.S. This is my first review, so please feel free to provide feedback on how I can improve. Thanks!
Zerest Audio is an audio startup from Singapore who just recently released their second major product, the Kagami Wireless earbuds, after their successful funding on Kickstarter. As a local backer, I figured I would do a review to help gain this company a little more publicity and help guide prospective buyers if these wireless earbuds are right for them. I received the “Midnight” colour version of the earbuds, which set me back SGD$109 (~USD$82), which was the Kickstarter early bird price at the time. Their MSRP is SGD$149 (~USD$112) on their Shopee store.
Their first products, the Kagami and Kagami+, were handmade wired IEMs with a warm V-shaped sound signature. Reviews for them are already on HeadFi, though do note that they are discontinued.
I used a Samsung Galaxy S23 Ultra via Bluetooth (AAC is as good as it gets) as my source, with a mix of locally stored MP3, FLAC, M4A, and WAV files for listening to music. Now on to the review.
Unboxing, Build Quality, and Comfort
The Kagami Wireless earbuds come in a higher quality box than their predecessor, which was handmade. This makes sense, since the Kagami Wireless are mass produced while the Kagami IEMs were entirely handmade, from box to product.
Inside are the earbuds, case, and documentation, along with a small black box containing its accessories. It includes a USB Type A to C cable, small suede-like pouch, and two different-sized pairs of ear tips (not pictured because I misplaced it, whoops).
A small gripe I have with the case design is that it easily topples over without the earbuds due to the weight of the cover.
As for comfort, these press-fit snugly into my ears. Of course, your mileage may vary. It seals well for me, which means that there’s good passive noise isolation from the outside and should help with bass extension. The fit is secure and comfortable, especially with its extremely light weight. In fact, these may be one of the most comfortable earbuds I ever wore! Zerest Audio definitely deserves some commendation for tackling ergonomics quite well.
Usability
Using it off and on for a few months now, connectivity between the earbuds and my phone is unfortunately sub-par. Dropouts aren’t uncommon, with audio randomly cutting out while walking or just handling my phone out of my pocket before normally reconnecting. I’m not sure if it’s just my particular set that’s exhibiting issues, but I haven’t seen similar complaints from other reviews.
On that note, let’s talk about the touch controls. They feel generally unresponsive, with quick, successive taps to adjust volume sometimes not registering, and having to wait almost 2 seconds for music to pause or resume after a single tap. I’ve resorted to just adjusting volume and changing tracks on my phone instead. This is certainly an area where I feel Zerest Audio can improve on.
Sound Quality
I’d say sound quality is the Kagami Wireless’ strongest point. To start off, the following graph is the frequency response measurements provided by Zerest Audio themselves, from a Kickstarter backer Q&A:
Weirdly they didn’t provide the x or y axes of the graph, so it’s difficult to quantify what the line objectively represents. Assuming it’s a raw FR graph, we can only surmise a bass boost and some treble dips past the upper mids. I can at least corroborate that it is somewhat accurate during my listening sessions (keeping in mind confirmation bias of course).
Regardless, to me, the bass sounds loose and boomy rather than tight and snappy. The attack of the dynamic driver in these frequencies sounds blunted and its decay exaggerated, especially in bass-heavy tracks. The difference in transducer speed becomes apparent when comparing it to my Moondrop Blessing 2 and only widens against the Etymotic ER3SE. Disappointing for sure, but not a total dealbreaker.
Additionally, while the bass boost is mostly constrained to 300Hz and below, the bass quantity could easily make the bass in crowded tracks seem overpowering and even bloated. Though if you’re a basshead, you’ll probably enjoy the thunderous bass these earbuds have to offer. Zerest Audio markets this product as “made by audiophiles for consumers”, and that really resounds here.
I perceive the Kagami Wireless’ lower midrange to be more or less neutral, with most instruments in this frequency range sounding balanced and natural. The upper midrange and treble frequencies, however, would be what I call the earbud’s Achilles’ heel. Female vocals lack air and breathiness, and while male vocals sound generally warm and natural enough, higher-pitched singers don’t sound as full. All this coupled with a boost in the vocal frequencies to balance out the heavy bass boost makes the tuning sound harsh and shouty in certain tracks.
Dips in the treble region underemphasizes crashing cymbals, high-hats, and other high-frequency instruments, causing a “bit-crushed”, low-resolution like sound, despite listening to high-quality music files. This is most noticeable in busy genres such as metal and rock and will probably bother metalheads like myself. On the other hand, I don’t think the recessed treble is something that a lot of people would notice immediately, unless you have a neutral reference to compare with.
All in all, I’d say that the Kagami Wireless sports a warm-leaning, bass-heavy and vocal-centric sound signature, though I wouldn’t fault critical listeners for calling it dark due to the sheer bass quantity and dips in the treble.
Equalisation
To smoothen the treble, restrain the bass, and overall make the earbuds sound more neutral, I used the following parametric EQ profile:
Preamp: -4.5 dB
Filter 1 (Peak): 60 Hz Gain -9.0 dB Q 0.250
Filter 2 (Peak): 4500 Hz Gain -6.0 dB Q 2.00
Filter 3 (Peak): 8000 Hz Gain 2.0 dB Q 4.000
Filter 4 (High Shelf): 8000 Hz Gain 4.5 dB Q 0.700
Filter 5 (Peak): 10500 Hz Gain -4.5 dB Q 3.000
The first filter adjusts the bass. Personally, the seal and fit of the earbuds is so good that despite reducing the bass by a whopping 9 dB, it still managed to retain enough punchiness and rumble to be enjoyable. Or maybe that’s just another testament of how much bass they come with out of the box. Feel free to adjust the gain according to your own taste.
The rest of the filters basically lowers the harsh upper mids to be more bearable whilst elevating the treble to restore that lost detail. With this EQ profile, I find the Kagami Wireless more enjoyable and listenable to over longer periods of time.
Soundstage & Imaging
The soundstage of the Kagami Wireless earbuds is decently wide but lacking height and depth, resulting in a flat and two-dimensional stage. In the realm of wireless in-ear buds though, especially at this price, these are completely fine and serviceable.
As for imaging, these are average for in-ears at this price too. Instruments and objects are placed in generally 3 “blobs”; left, right, and center. In part due to its soundstage, instrumental separation suffers, so they don’t sound the most defined nor precise. There is some amount of layering to be heard, but only if the track allows it.
Conclusion
With all my criticism with its bass and treble, at SGD$149 (~USD$112), I still think that the Kagami Wireless is a decent buy for those looking for a “bass cannon” experience. It’s neither a value king at that price, nor is its sound quality so unpleasant to merit disapproval.
Consumers will likely enjoy the bass boost provided without vocals sounding wonky or being heavily smeared, like one would hear in most cheaper consumer wireless earbuds. Audiophiles, on the other hand, may find its bass overpowering and treble lacking. For bassheads though, I still think it’s worth considering in its price range.
P.S. This is my first review, so please feel free to provide feedback on how I can improve. Thanks!
