This is a Koss headphones and earphones review. Koss Corporation is an American based company that specializes in the designing and manufacturing of different kinds of earphones, headsets, and headphones. Unlike certain other headphone companies like Marshalls (which also specializes in electric amplifiers) or Logitech (which produces many different electronic products), Koss specializes in producing only headphone and earphone products.
Koss headphones and earphones are, for the most part, very inexpensive. The most expensive headphones in their selection only costs about $125 if bought through Amazon. All the rest of their products are sold for under $100, and some of their cheap earphones are sold for as little as little as $10. The common purpose is to make good quality listening devices available at very reasonable prices.
For the most part, Koss products are very light and very portable. Many of their products are popular as sports headphones or ear buds for running. Frequency range is normally quite wide, and harmonic distortion is usually lower than 0.2% – 0.3%. Most are optimized for use with Apple products like iPhones, iPads, iPods. And most Koss products have a limited lifetime warranty.
There is a fair range of diversity in Koss products. Some are noise canceling headphones, and others allow sound penetration. Some are in-ear headphones, some are over-head headband headphones, and some are clip-on earphones. Some are headsets with microphone and remote for use with cell phones and MP3 players. Some of the most popular products are described below:
Koss “The Plug” Ear Buds
Koss “The Plug” In-Ear Headphones (Black) are a very popular, inexpensive, high-selling set of sound isolating ear buds. On Amazon they cost only about $10, and they earn a score of about 3.8 stars out of 5 in Amazon reviews. There is a bit of a discrepancy about the frequency range. Amazon lists the range as 16 – 23,000 hertz, but the official Koss website lists the frequency range as 10 – 20,000 hertz. Apparently Amazon has a misprint. The connecting cable is 4 feet long with a standard 1/8 inch connecting cord. They come in several different colours. The soft memory foam sleeves provide a very high noise isolation. Sound distortion is less than 0.3%, and sensitivity is 112 dB SPL. Impedance is very low at just 16 ohms, so it is easily powered by any cell phone, MP3 player, or portable device. It comes with the standard Koss limited lifetime warranty.
Koss Stereophone Sportclip
KSC75 Sportclip Earphone is a clip-on earphone, optimized for sports, exercise, and for travel. On Amazon it cost about $22, and it gets a score of about 4.3 stars out of 5 for customer satisfaction. Another variety of the Sportsclip would be the Koss KSC75 Stereophone which, is a bit cheaper at about $15 on Amazon. There are only a few slight differences between the two models. What they have in common is a frequency range of 15 hertz to 25,000 hertz, an impedance of about 60 ohms, and a harmonic distortion level of less than 0.2%. They have a 4 foot connecting cable with a standard 1/8 inch jack plug. The clip-on design is open-back, so they have no noise isolation. They are very portable, they only weigh about 1.4 ounces, and they easily fit into a shirt pocket or a purse. It has the Koss standard lifetime limited warranty.
Koss PortaPro Headphones with Case is a very light, portable, on-ear headband headphone. On Amazon it sells for about $40, and it earns an excellent score of 4.5 stars out of five. This is a very popular, high-selling product. It collapses and folds into a very small, compact unit that easily fits into a purse of a briefcase. Frequency response is 15 hertz to 25,000 hertz, impedance is about 60 ohms, and sensitivity is 101 dB SPL. Harmonic sound distortion is below 0.2%. It comes with several comfort features, including pivoting ear plates, a sliding headband adjustment, foam temple ear cushions, and a very light weight of just 6.4 ounces. Unfortunately, the on-ear design has no noise isolation. PortaPro has a standard 4-foot connecting cable with an L-shaped 1/8 inch (3.5 mm) jack plug. They come with the standard Koss limited lifetime warranty.
Koss Portapro KTC Headset
Koss Porta Pro KTC On-Ear Ultimate Portable Hephone for iPhone, iPod and iPad sells for about $49 on Amazon with a customer satisfaction score of about 4.2 stars out of 5 in Amazon reviews. This is very much like the regular PortaPro headphones, except this has a KTC (Koss Touch Control) on-cable 3-button remote and microphone to use with cell phones and portable devices. It works best with Apple devices like iPod, iPhone, and iPad. Besides the on-cord remote and mic, features and specifications are the same as those of the PortaPro. Frequency range is 15 – 25,000 hertz, impedance is 60 ohms, and sound harmonic distortion is less than 0.2% with a SPL sensitivity of 101 dB. The connecting cable is 4 feet long with a standard 1/8 inch (3.5mm) jack plug. Comfort features include a light weight of 6.4 ounces, soft foam ear pads on pivoting ear plates, sliding headband adjustment, foam temple cushions, and a comfort zone pressure adjustment. They have a Koss limited lifetime warranty.
Koss KMO10 Earbuds
Koss KMO10 Earbud Headphone (KMO10P) come in two colors: pink or green. They cost from about $9 to $16 dollars, depending on which style you choose. These are not well known, and are likely to be discontinued soon. They fit on the outside of the ear much like the Apple ear buds. Cable length is 4 feet. Impedance is only 16 ohms, so they work well for portable devices like cell phones and MP3 players. Frequency range is limited, only 60 hertz to 20,000 hertz, so they don’t have very much bass. Like most Koss products, they come with a limited lifetime warranty.
Koss UR40 Headphones
Koss UR40 Collapsible Over-Ear Headphones Koss UR40 Collapsible Over-Ear Headphones cost only $29 on Amazon, which is a discount of about $10 off the list price, and they get a score of about 4.0 stars out of 5 among reviewers. They are very light over-ear (circumaural) headband headphones which weigh only a little more than 6 ounces. The ear cups are open-backed, so they do allow some sound penetration, but they also allow some air circulation to keep the user’s ears from getting too hot and uncomfortable. Frequency range is 15 hertz to 22,000 hertz. They use a 4 foot, dual-entry connecting cable, they have a sensitivity of 98 dB SPL/1 mW, and they have an impedance of about $60 ohms. Like most other Koss headphones, they come with a limited lifetime warranty.
Koss ProDj200 Headphones
Koss ProDj200 Studio Headphone – Black/Silver cost about $70 on Amazon. They get a very good score of 4.6 stars out of 5. As the name suggests, these are suitable for professional work like DJ and Studio applications. This is a folding, closed-back, on-ear, noise isolating headphone. It is also optimized for use with MP3 players, iPhones, iPods, and other mobile devices with a much lower impedance of 38 ohms, so that it needs much less power to operate it. The ProDj200 has a frequency response range of 10 hertz to 25 hertz, which is more than enough to cover all the low bass tones and high treble pitches that the human hearing can hear. SPL sensitivity is rated at 99 dB. It comes with two detachable, interchangeable connecting cables. One cable is a coiled cord that stretches to about 8 feet, and the other is a 4 foot cord with a 3-button on-cord KTC (Koss Touch Control) remote and microphone. They come with a limited lifetime warranty.
Koss Pro-4AA Headphones
Koss Pro-4AA Studio Quality Headphones are a bit more expensive than most Koss products, but they also come with several impressive features. They cost about $89 on Amazon, and they earn an impressive score of about 4.4 stars out of 5 among Amazon reviewers. These use closed-back ear cups with a over-ear, circumaural ear cushions for a high level of sound isolation. They get a wide frequency range of 10 hertz to 25,000 hertz with a high impedance of 250 ohms for professional sound quality. High impedance make these headphones more suitable for professional desktop equipment, so you would probably need a portable headphone amplifier to use this with a portable device like a cell phone or an MP3 player. It uses a single-side-entry, stretching coiled cable which extends to 8 feet when extra length is needed. Like all Koss products, this has a limited lifetime warranty.