Picture of the Koss KEB30K Noise Isolating Earbuds, package front view.

Koss Earbud Headphones KEB30K Headset Review

The Koss earbud headphones KEB30K noise isolating earphones overly emphasize midrange, sacrificing decent bass and treble response in the process.  Good for novice listeners though, who don’t really care about such things.

The drivers, while excellent at reproducing vocal vowel sounds, the lows, due to the excessively miniature size of these buds, do indeed suffer. What you gain in miniaturization, you lose in richness of sound. The high frequencies also seem to roll off too abruptly in the audio response.  As we write this, we’re listening to Shania Twain’s “Any Man of Mine,” country waltz song, and through these stereophones, the kick drums, that should dominate the music during the verses, sound like a kid tapping a little pencil on a desk; the deep bass barely perceptible.  With our iPad Mini 2 equalizer on flat, the lack of high end (weak symbols and S and T vocal sounds) reminds us of the AM radio listening days, the high frequencies above 5 KHz are completely attenuated.

But on a positive note, these earbuds accept boosted bass and treble from an equalizer at fifty percent volume levels, without noticeably distorting. So you can restore the reduced ends of the audio spectrum bass if your media device has an equalizer.  Also, the noise isolation properties function well to significantly reduce surrounding ambient noise from reaching your eardrums while listening to pop, rock, and country music.  But insufficient acoustic noise shielding here renders the KEB30K earphones not well suited for the quiet passages of classical and a Capella pieces.  For the casual mainstream music listener however, the KEB30K buds work reasonably well.

Picture of the Koss KEB30K Noise Isolating Earbuds, unpacked view, showing the earphones, ear tips, instructions, storage case, and instructions.
The Koss KEB30K Noise Isolating Earbuds, unpacked view, showing the earphones, ear tips, instructions, storage case, and instructions. Koss earbud headphones KEB30K review.


Koss Earbud Headphones KEB30K Benefits, Pros, Features, and Advantages  

Convenient Storage Case Provided

The included stow-away, leather-looking case features a self-closing, spring-loaded opening, that prevents these stereophones from escaping.

Included Warranty and Disposal Instructions

Instructions tell of how to safely dispose of spent earbuds.  Nothing though about avoiding possible hearing loss, or how to insert them, except for a brief diagram on the back of the original carton.

Fit Small Ears Comfortably

A pair of small-diameter replaceable ear tips is included for those with smaller ear canals.  Apply these if your ears have smaller openings.

Built In Volume Control 

A slider volume control is provided.  Note however that this differs from other headsets that feature UP and DOWN volume setting buttons.  Those units rely on sending command signals to the hosting mobile device, which in turn adjusts its volume output.  In these earbuds however, your device volume remains unchanged while the variable resister in the volume slider is what regulates the volume.  No commands are sent to the device.  In fact, the cord here lacks that fourth command conductor.  True, you may still control the volume via your device, but you would be unable to change the device volume setting via this control on the KEB30K.  So if you’re going to use the device to set volume levels, we recommend setting the control here to maximum.  Likewise, if you want to use this control for volume adjustment, set the device volume to maximum.

Strain Relief on Some Joints

Flexible and effective strain relief on the 3.5 mm male gold-plated plug (that inserts into your audio device). Each earpiece also features rigid strain relief as well. However, the built in volume control has none.

In Ear Wearing

The KEB30K drivers insert deep into the ear, touching the eardrum, for improved fidelity and isolation from surrounding sounds and noises.

Ported Speaker Design

There’s a small hole at the rear of each earphone, that affects the sound somewhat when blocked.  Apparently, these buds require this port as part of their acoustical system, to produce its specified frequency response curve.

Acceptable Fidelity, Decent Sound

Reproduces low-mid, midrange, and the lowest-high audio frequencies well. Not excessive sound coloration or harshness thus in this part of the spectrum, although as noted, the low bass and high treble output appears way reduced when playing on flat, which effectively exaggerates the midrange audio.

Visible LEFT and RIGHT Channel Labels

The left and right silver and black earbuds are printed with easy-to-see L and R letters respectively, located on the inside side of each cord stem.

Symmetrical Driver Design

Hard to confuse LEFT and RIGHT speakers. The KEB30K implements a symmetrical ear bud design, in which the LEFT bud fits most comfortably and sounds the best, in the left ear, and the RIGHT bud fits best into the RIGHT ear.

Good Sensitivity

They play plenty loud with even the lowest power media players.

Long Audio Cable

Over three feet of flexible audio cable is provided from the bottom of the Y vertex to the plug, and an additional twelve inches of cable from the top of the Y to the drivers.

Gold Plated Connector

A stereo gold-plated 3.5mm male plug (three conductor) promotes longer-lasting, reliable connectivity with less intermittent operation as the plug becomes dirty or corroded.  The connections remain true for the life of the earbuds.

Low Magnetism Leakage

You can make the drivers in other earphones repel each other if you position them close to each other. And they’d even stick to some surfaces. However no discernible magnetism leaks out of these pearl-like driver assemblies.

Multiple Ear Cushion Tips Included

Koss supplies three pairs (small, medium, and large) semi-transparent silicone ear tips.


At between $8 and $18 per pair, depending on where you purchase, the KEB30K  earphones cost quiet a bit less than Apple’s Earpods model ($29.99), and feature about as much sacrificed sound quality as well. If you’re at all sensitive to how faithfully your earbuds recreate your music, then raise the stakes, and skip over these buds and buy the Earpods instead. Believe us.  Once you become accustomed to hearing truly high fidelity music through high quality earbuds, you won’t be sorry you spent a bit more up front.

Limited Lifetime Warranty

Picture of the Koss KEB30K Noise Isolating Earbuds, package back view, showing specifications and ear tips.
The Koss KEB30K Noise Isolating Earbuds, package back view, showing specifications and ear tips. Koss earbud headphones KEB30K review.

Disadvantages, Problems, Cons, Limitations, and Concerns about Koss Earbud Headphones KEB30K 

No Cord Slider

This would enable adjustment of how big the Y cable joint is, where the left and right ear driver cables come together into one. Such a feature augments comfort and reduces catching and snagging on clothes buttons and zippers, and as cheap as it is to implement, really should appear on all earbuds.

In Ear Design Means Less Sharable

They’re more apt to become soiled with ear wax, which you may wish to avoid transferring from person to person by sharing these buds.

Volume Control Subject to Failure

Since the volume level setter here is a variable resister, it can become dirty and  “staticy,” and fail after a much shorter time than the more advanced, software-regulated, pushbutton controls of headphones with full remote control functions built in.

Easy to Hurt Ears

Be careful though, not to blast them too loudly, because they can generate enough volume to mask out exterior sounds like trucks coming. We’d recommend against playing these while walking along and across busy roads, because while they still allow in much external sound, they still, particularly while playing your music loudly, may prevent you from hearing approaching vehicles.

Also, these buds produced somewhat higher levels of notably distorted audio than the original iPod stock buds.  Note that these buds sound significantly harsher and “cheaper” than Apple’s current stock earbud offerings.

Reduce Outside Noises

May be inappropriate for certain environments, where the user would like to hear well the surrounding noise. Since these buds “stop up” the ear canal, they somewhat reduce outside noises from being heard while listening. So you may not perceive important sounds (like your baby crying or husband calling).

Could Annoy Travelers Near You

On the other hand, since the degree of sound isolation is reciprocal (works equally as well (or not) for keeping internal sound in while fencing external sounds out), and the KEB30K does not keep the music inside the ear very well. Some media sounds escape to the outside via the rear ports.  So you may disturb nearby passengers on trains and planes, if you play your music too loudly.

Likely Not Fixable

Given the very small audio cables and connections here, these earphones cannot be repaired practically, as the wires inside are hair-thin. So once they break, they’re finished. No biggie for el cheapo earbuds like these. But we’d still prefer that our earbuds be repairable should they fail, the more expensive they become.


  • Frequency response: 15 – 20,000 Hz.
  • Sound pressure level: 109 DB.
  • Impedance: 16 ohms.
  • Cord: 1.2M, 47.25 inches, type Y.

Our Rating

We rate the Koss KEB30K Noise Isolating Earbuds at 75 out of 100. Very far from the best earbuds, they’re among the lowest priced. Their sound quality equals their low cost.  They can fall out of ears too often and require frequent adjustments to keep them properly positioned. While they’re great for kids and beginner listeners, you’d certainly grow tired of them quickly. So we decline recommending them to any audiophiles or refined music listeners, to another. *grin*

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References for Koss Earbud Headphones KEB30K 


Revision History

  • 2019-02-19: Added key phrase targeting, more tags and subheadings, and fixed some typos.
  • 2017-02-27: Revised the tags list.  Added the Related Posts section.
  • 2015-10-15: Added appropriate tags.
  • 2015-09-29: Originally published.