Skip Navigation

Koss RUK40

On-ear headphones (Black)

2 Reviews

Item # 245RUK40B

This item is no longer available.

Shop all Headphones


Our take on the Koss RUK40

Impressive sound at a great price

Headphone pioneer Koss has long been at the forefront of producing inexpensive headphones that deliver involving, detailed sound. The RUK40 is their latest triumph of sound quality and comfort at a low price. These unassuming on-ear headphones will impress with their tonal balance and openness. And the cushiony earpads will make it easy to wear the RUK40 for hours on end, for non-stop listening on the go. Available in five colors, these are a great buy if you're looking for comfort and portability in a sweet-sounding set of on-ears.

Product Highlights:

  • flat, tangle-resistant 4-foot miniplug cable
  • pivoting earpieces for custom fit
  • frequency response: 20-20,000 Hz
  • sensitivity: 98 dB
  • impedance: 36 ohms
  • warranty: lifetime
  • Our 60-day money-back guarantee

What's in the Box:

  • Black on-ear headphones with a 4' flat cable (3.5mm plug)

Wanted a lightweight, good sound for when I run or walk. These surpassed my expectation.

Gadget lover, Ohio


Koss RUK40 Reviews

Average Customer Review(s):

(2 Reviews)

Lightweight quality

Gadget lover from Ohio on 7/12/2013

Crutchfield Customer Review (What's this?)

Wanted a lightweight, good sound for when I run or walk. These surpassed my expectation.

Pros: Lightweight, comfortable, good sound, works well with iPhone

Cons: Fit is not as snug as I would like


Nancy from Texas on 12/31/2012

Crutchfield Customer Review (What's this?)

Only had these a short time, but my teenage son loves them. No complaints. Price was reasonable.




Hands-on research

Features and Specs

Fit Style On-ear
Earcup Type Closed
Earcup Width x Height 2.467" x 2.467"
Noise-canceling No
Bluetooth No
Mic For Taking Calls No
iPhone Control ---
Lightning Connector No
Android Control ---
Frequency Response 20-20k Hz
Sensitivity 98 dB
Impedance 36 Ohms
Weight 2.9 ounces
Cord Length 48"
1/4-inch Adapter Included No
Volume Control No
Parts Warranty Lifetime
Labor Warranty Lifetime

Product Research


Overview: The Koss Rukus-series RUK40s are lightweight on-ear headphones. The uniquely designed ear cushions help eliminate ear fatigue, so you can listen comfortably for hours. The RUK40s use dynamic elements for smooth bass and a wide frequency response. The earcups pivot so you can lay them flat for storage or packing in a suitcase.

Cord: The headphones have a 4' tangle-resistant flat cord terminates with a slender 3.5mm plug. The narrow collar on the plug allows you to connect to recessed headphone jacks or portable digital music devices with hard cases.

Warranty: The RUK40s are covered by the Koss Stereophones Limited Lifetime Warranty.


  • Frequency Response: 20Hz-20kHz
  • Sensitivity (dB/1mW): 98dB
  • Nominal Impedance: 36 ohms

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.