KB EAR KB02: The Affordable Bone Conduction Driver IEM

KB EAR is one of the audio companies that made some name in the audio market a few years ago with some of their recognisable  models like KS1, Robin, Lark, Ormosia, Ink 1/2 and BeLieve which was their limited model. A few months ago, KEEPHIFI contacted me to ask if I could do a review on their latest product and I agreeably responded to their request for product assessment as It's been a long time since I reviewed a unit from KBEar. What I have here is their latest entry-level model and this one has an unusual driver configuration for its price. This is KB EAR KB02 and it has a hybrid driver set-up consisting of a dynamic driver and a bone conduction driver housed in a resin shell chassis.

About its drivers, the dynamic driver is a 10mm dual-chambered structure with beryllium-plated diaphragm on it while the bone conduction driver is a contact-type one with that usually works in both air and bone conduction as the sound waves travels inside within our auditory system and its also transmit through our ear's cartilage that was connected to the bone conduction. My knowledge about this type of driver technology became more diverse as there are many ways to transmit sound waves via vibrations either on aural cartilage or directly to the skull.

The combination performance of both dynamic driver and bone conduction driver will deliver that deep and striking bass quality, then a clear, rich and luminating midrange and high frequencies along with added depth and ambience effect from the latter driver.

The drivers were then encapsulated in a medium-size UIEM-style resin shell and it was solidly structured with a some asymmetrical vibrant and deep lustre pattern on the faceplate. KBEar offers three colourway options on its faceplate; violet, blue and brown for your preferred colour choice. This model uses a 0.78mm bi-pin connector as its interlocking mechanism with its detachable cable.

As for its stock cable, it has 4-core high purity OFC cable which is quite flexible and it doesn't produce any microphonics effect while maintaining a smooth audio transmission with a minimal chance of signal loss. On its termination end, it has a gold-plated 3.mm single-ended plug.

The shells offer an ergonomic design as it fits well into my lugholes without any sort of discomfort and also, it offers a good passive noise isolation due to better sealing as it blocks some unwanted external noises from the outside surroundings.

Regarding its product packaging, the KB02 has a rather simple presentation with basic inclusions on its packaging box.

These are the following contents that were included inside of its packaging box:

• Pair of KB EAR KB02 IEM transducer pieces.
• Stock cable
• Three (3) pairs of KB EAR 07 ear tips in different standard sizes.
• Three (3) pairs of AET08 ear tips in different standard sizes.
• Three (3) pairs of AET16 ear tips in different standard sizes.
• Paperwork like instruction manual and warranty card.

When it comes to driveability and amplification, The KB EAR KB02 is relatively sensitive enough that it can be driven by the sources with decent power output even with normal gain mode. But this one will even scale better if it was paired on devices with medium gain or high gain output; it sounds more dynamic and full without any clippings or distortion at all.

The sound profile of this set is definitely a V-shaped sounding one as it has more emphasis on both low frequency and high frequency that makes more coloured and fun sounding that gives an engaging type of sound that most casual listeners will truly enjoy.

LOW/BASS:

The bass quality is quite more balanced as it has noticeable sub bass presence and with a satisfactory amount of mid bass texture. Due to the implementation of the bone conduction driver inside, it adds a more deep reverberating effect on its sub bass quality to give more ambiance while it delivers a punchy and a pithy sound on its bass response but if you are looking for rich and authoritative bass quality, this one is not one you are looking for.

The sub bass presence has clearly perceived that we will feel those rumbling, pulsating and reverberations that were generated from percussives, strings and electronic instruments like kick bass drums, drum machines, low tuned bass guitars and double-basses, and lastly, synthesisers that are usually found on certain music genres like hip-hop, synth-pop and dance music. The mid bass texture is rather decent enough to give an adequate note weight on some bass-noted instruments and low octave male vocals. The bass guitars sound resonant while double-basses have a rasping sound as we will also notice their lack of heft on their respective note, and the bass kick drums sound a bit resonant yet with a softer strike. On male vocals like bass and bass-baritones, they have that deep and resonating voices but again it has that lack of volume and richness as it will give a dark tone to give that gravelly and dusky sound characteristics that these types of vocals are known for.

MIDRANGE:

The midrange presentation of this one is indeed recessed as I noticed that vocals and instruments were at peripheral position on its overall frequency range. But still, it maintains a balanced presentation as it has ample warmth with an added energy to on the  upper midrange part as both vocals and instruments will some benefited on its tuning like a smoother and sufficiently warm sound on male vocals, a shimmery and energetic female vocals, a bright and crisper sound on strings, a brassy and brilliant sound on brass instruments, a sharper and a bit metallic sound on percussives, and then a vivid and vibrant sounds on woodwinds.

On male vocals, a smooth and tan sound on baritones, a spicy and brassy sound on tenors and then, a velvety and coppery sound on countertenors. When it comes to female vocals, contraltos have enough lushness and rich tone from their chesty vocals, a fiery and spirited sound on mezzo-sopranos and then, a shimmering and a bit metallic sound on sopranos.

As for instruments, on string ones, guitars have a crisp and bright sound, a more vibrant sound on violins and a brilliant sound on cellos. The woodwind instruments like concert flutes and piccolos, in corresponding order, have these brilliant and intense sound characteristics. On brasses like trumpets and trombones, they sound brilliant and rounded respectively. And last but not the least, on the percussive ones,  snares have a penetrating sound, tom-toms have that resonant sound, field drums have a sonorous sound on every stroke and kettledrums have a rumbling and yet a bit dry sound. Pianos seem to have a rather balanced tone as it has a rich, sweet and vibrant sound.

HIGHS/TREBLE:

The treble response on this one is quite lustre and also relatively balanced sounding but I noticed that its airy extension is rather meagre in my opinion given that beryllium-coated dynamic drivers are known for its sufficient airy treble quality. I noticed that there is a noticeable elevation on upper mids up to the presence part to give a sense of clarity and definition on some vocals and instruments but there are some instances of a bit metallic, piercing and sharp sound on some tracks.

The brilliance section of this one is that as I mentioned a while ago, it has an inadequate airy extension with an ample sparkle that would be enough for harmonic presence. Cymbals have a lustrous sound, hi-hats sound dry and dull, celestas have those sweet sounds and glockenspiels have those thin sounds.

SOUNDSTAGE, IMAGING & OTHER TECHNICALITIES:

On how this set projects its sound/speaker stage overall dimensions, it has a reasonable width on its lateral span from left to right, and also a good height reach and satisfactory depth that makes it moderately roomy within my head room.  The stereo imaging presents a more concave stereo presentation with just a decent layering on its soundscape and acceptable separation of musical elements in which it has less precise on locating the exact placements of vocals and instruments.

The cohesiveness of its hybrid driver configuration is quite impressive as the performance of the contact-type bone conduction driver will add some depth and ambience while its beryllium-plated dynamic driver delivers the clear, clean and crisp sound. The resolution capabilities of this one is pretty decent enough to highlight the varying degree of loudness of dynamics on between chorale lines and instrumental passages, while on its micro-detail retrieval is sufficient but not it doesn’t have that sharp definition on extracting grains, nuances and subtleties from a sonic background from a played audio track.

PEER COMPARISONS:

Since I don’t have a particular set that has a similar price range with the KB02 but I would compare it to the sets with beryllium-coated dynamic drivers.

SIVGA QUE

• This is SIVGA’s entry-level set and it only has a single driver configuration.
• It uses a beryllium-coated diaphragm dynamic driver just like the KB02.
• It was encased in a composite shell chassis made of wooden faceplate panels and a metal alloy.
• This one is well-packed with quality accessories including a high quality stock cable and a storage case made of protein leather.
• This one has a bright U-shaped sound profile that is also quite a well-coloured tonality.
• It has punchy bass response, recessed yet balanced with ample weight on it enough to highlight the texture and details of vocals and instruments and a tad brighter and shimmering treble response with good amount of air on it.
• As for its technicalities, this one can project a spacious sound/speaker stage, good layering and separation, and also pretty well resolving on how its beryllium-coated driver performs.

KIWI EARS CADENZA

• The inaugural model of KIWI EARS but unlike the KB02, it has only a single dynamic driver.
• This one also sports a beryllium-coated dynamic driver.
• It has a resin shell chassis that encapsulates its single driver set-up.
• Like all Kiwi Ears sets, this one has a decent inclusions but it offers three types of ear tips.
• This one has a U-shaped type of sound as it has a sufficient punchy bass response, a bit recessed yet ample textured midrange and a smoother but less airy treble quality.
• Regarding its technical performance, it has a rather intimate sound/speaker stage, a satisfactory layering and less resolving, particularly on micro-dynamics.

TWISTURA D-MAJOR

• Another inaugural model from a recently established audio company, this model has a single driver set-up.
• Another IEM that also has a beryllium-coated dynamic driver.
• It has a metal alloy shell structure and  it has a detachable nozzle with tuning filters.
• This one is well-packed with a quantifying amount of accessories that even includes a DAC/Amp dongle.
• Due to its detachable nozzles, it offers three types of tuning profiles and all of them are of U-shaped sound signature from a warm to the brighter tonality.
• It has a good sound/speaker stage dimension with a good  resolving resolution capabilities mainly on micro-dynamics.

It appears that KB EAR is able to offer an IEM with an unusual driver technology at an affordable price and as we all know about this type of driver that implemented to other sets are usually priced around US$200/£140 but this audio company actually delivers it. It also has a likeable tonal profile that makes it more enjoyable as we will delve upon its sound quality that we are able to feel that depth and reverberation of its bass quality, a rich and smooth vocals and instruments on its midrange and then a smooth and inoffensive treble response.

There are some limitations and compromises about the tuning choice of this unit as there are some aspects that need a bit of polishing but for its asking price, I don't think that it will be not a major issue at all as this set is probably one of the best releases from KB EAR.

KB EAR KB02 is now available at KEEPHIFI, I provided a non-affiliated link below if you are interested about this model.

LINK: https://keephifi.com/products/kbear-kb02

SPECIFICATION:

MODEL: KB EAR KB02

IMPEDANCE: 40Ω

SENSITIVITY: 108dB

FREQUENCY RESPONSE: 20Hz – 20KHz

CABLE LENGTH: 1.2M

PIN TYPE:  2-PIN CONNECTOR (0.78mm)

PLUG TYPE: 3.5mm

DRIVER UNIT(S): (1) DYNAMIC DRIVER + (1) ELASCTIC-TYPE BONE CONDUCTION DRIVER

PROS:

● A lightweight, solid resin-like shell chassis.

● Offers a comfortable fitting with good noise isolation.

● Hybrid driver configuration.

● Probably one of the most affordable set with a bone conduction driver which is quite unusual for its price.

● Three types of ear tips to choose from.

● A sound quality which is fun and engaging which will be enjoyable for a casual listening session.

● Tactile and incisive  bass response.

● Warm and a bit energetic midrange quality.

● Smooth and rich sounding male vocals.

● Full, crisp and brilliant sound on some instruments to sound somehow closer to natural sound.

● A tad and vibrant treble response.

● Commendable cohesion on its hybrid driver performance.

CONS:

● Coloured sound profile, not for neutral heads.

● Not even for bassheads as the bass quality of this one is less punchy, not boomy that makes it less authoritative.

● Recessed midrange presentation.

● Instances of tinny, piercing and metallic sound.

● Intimate head stage presentation.

● Less sharp definition on micro-detail retrieval.

● No storage case.

TRACKS TESTED: ( * = 16-bit FLAC, ** = 24-bit FLAC, *'* = MQA, '*' = DSD, *'= .WAV)

Alison Krauss -When You Say Nothing At All *

Jade Wiedlin - Blue Kiss**

Led Zeppelin - When The Levee Breaks **

Mountain - Mississippi Queen *

Queen - Killer Queen **

Guns N' Roses - Patience *'*

Eric Clapton - Tears in Heaven '*'

Sergio Mendes- Never Gonna Let You Go '*'

Pearl Jam - Daughter **

Roselia - Hidamari Rhodonite *

Assassin - Fight (To Stop The Tyranny)*

Celtic Frost- Visual Aggression *

New Order - Blue Monday *

The Corrs- What Can I do (unplugged version) *

Jimi Hendrix Experience - Voodoo Child *

The Madness- Buggy Trousers *

Metallica - Motorbreath **

Mariah Carey- Always Be My Baby *

Destiny's Child - Say My Name *

Malice Mizer- Au Revoir *

Mozart - Lacrimosa *

New York Philharmonic Orchestra - Dvorak- Symphony 9 " From the New World." *

Eva Cassidy - Fields of Gold (Sting cover)*

Michael Jackson - Give In To Me *

Exciter - Violence and Force *

Diana Krall - Stop This World **

Debbie Gibson - Foolish Beat *'*

The Sisters of Mercy – Lucretia My Reflection**

Suzanne Vega – Luka **

Lauren Christy – Steep *

Ottoman Mehter - Hucum Marsi *

Diana Damrau - Mozart: Die Zauberflöte*

Type O Negative - Black No.1 *

Felix Ayo - Vivaldi: Presto **

Three Tenors - Nessum Dorma *

Mercyful Fate - Witches' Dance *

P.S.

I am not affiliated to KB EAR nor receive monetary incentives and financial gains as they provide me a review unit for an exchange of factual and sincere feedback from yours truly.

Once again, I would like to send my gratitude to KB EAR REP for providing this review unit as a loaner unit. I truly appreciate her generosity and trust towards me and other reviewers.