KB Ear F1 Earphone Review – Refreshing

KB Ear F1 featured

Are you bored with the current trend of pseudo-custom type shells that everyone is doing? Sure they fit and isolate noise well but sometimes you want to stand out from the crowd. Today we review the KB Ear F1 single balanced armature driver earphone that has a unique style of its own.

This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

  • Handsome, original design
  • Lightweight and comfortable
  • Detachable MMCX cable
  • Tight bass and clear midrange

  • No ridge on nozzle to secure eartips
  • Occasional sibilance

Package and Accessories

The F1 comes in a black box with green highlights and a clear image of the earphones on the front. On the back is a list of specifications. Inside the box, the earphones are seated in a soft foam insert, along with 2 extra pairs of silicone eartips. There’s a smaller box here too, which contains the detachable MMCX cable and 3 additional pairs of KZ Starline silicone eartips.

Build Quality and Design

The KB Ear F1 is nothing if not striking from a design standpoint. It’s an original and easily identifiable look that is sure to be a conversation starter. The body is L-shaped with an angled corner and made from an amber-coloured transparent resin (also available in black colour).

Internal components and the single balanced armature driver are clearly visible within the shells. There’s a KB Ear logo in silver on one side of each shell too, which is handy for identifying the left and right earpieces.

On one end of the body is the MMCX connector and on the other is the nozzle. The MMCX connectors have a crisp, tactile click when attaching the cable. However, the nozzles do not have any lip or ridge so I had a hard time finding eartips that did not slip off easily (I settled on some large Spinfits).

Due to the nature of this design, the F1 can be worn either cable-down or over-ear, adding versatility and function. My preference for this IEM is cable-down. As far as build quality goes, the F1 is fantastic for a budget earphone and gets extra points for originality.

KB Ear F1 side view
Comfort and Noise Isolation

Comfort with the F1 is great, whether worn cable-down or over-ear. It’s very small and lightweight and the only part that really comes into contact with your ears are the eartips. Noise isolation is about average and suitable for most everyday environments. Noise leak is minimal.

KB Ear F1 underside and nozzle

The included detachable cable is pretty good for a budget earphone. It is a twisted 4-strand that is pliable and has no microphonics. At the top are transparent plastic MMCX connectors. There is no memory wire or pre-formed ear guides present as the cable is designed to be worn either down or over-ear.

The Y-split is a small, lightweight aluminium cylinder which, unfortunately, is positioned way too far down the cable. With the position of the Y-split, the thinness of the wires above it and lack of a chin slider the cable is very prone to tangling.


Gear used for testing includes the FiiO M6 and iBasso DX120 DAPs. The F1 is easy to drive and does not require a powerful source; it will work fine with any smartphone or DAP.

The KB Ear F1 has a fairly balanced signature with a polite bass, clear midrange and crisp, detailed treble. For a single balanced armature driver IEM the F1 delivers an impressive full-range sound with good clarity and tone.

KB Ear F1 frequency response

The F1’s bass is surprisingly satisfying for a single BA driver. Sure, it can’t compete with dynamic drivers when it comes to impact and authority but it’s no slouch either. Sub-bass depth is only moderate, which remains (in my opinion) the biggest drawback with BA drivers.

Lower bass notes create a gratifying resonance and light rumble that can actually be felt physically but the extension in the lowest registers is retrained. Mid-bass, however, has a nice weight and delivers some nice punch while staying nimble and controlled.


The F1 has a fairly typical midrange with a boost in the upper mids to add some clarity and presence. Male and female vocals sound natural and lively and rise up clearly above the polite bass and relative balance of the upper midrange.

Firing up Riverside’s “We Got Used To Us”, it’s easy to get wrapped up in the lyrics without distraction. I will say though, that on occasion the F1 can be a little sibilant but thankfully it doesn’t happen too often. Just be warned though and try to steer clear of inherently sibilant recordings (like almost anything by The Pineapple Thief).


A healthy amount of lower treble adds clarity and some brightness, along with the aforementioned sibilance. The treble is probably the weakest area of the F1 but it’s not bad for a budget IEM. It adds a sense of openness and energy to the sound but is at times a little strident.


The F1’s soundstage has moderate dimensions and feels more like a large room than a hall. It has surprising depth and moderate width. The stage is stable but it does start to deteriorate during busier segments. For the most part though, positioning and imaging are what you would expect for earphones in this price segment.

KB Ear F1 internals


There are some things to really like about the KB Ear F1. I love the design and aesthetic (especially the transparent amber version). I also like what KB Ear has achieved with the sound from a single BA driver. If they could just get a handle on that occasional sibilance they would have a real winner on their hands.

As it stands though, the F1 is a worthy earphone which I would readily recommend, especially for anyone who wants something a little different from the norm. It also points to some real potential from this fledgeling new brand and I’m looking forward to seeing what they deliver next.

  • Driver: 1 balanced armature
  • Impedance 22Ω
  • Frequency Response: 20Hz-20kHz
  • Sensitivity: 105±3db

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