The Venerable Koss Porta Pro

Long before I became professionally involved with headphones, the Koss Porta Pro was a great little portable headphone. In fact, it was one of the first headphones designed particularly for portable applications. It has remained relatively unchanged to this day ...

... thank goodness. If it ain't broke ...

Koss Porta Pro ($49)
Cast you mind way back to the early eighties --- Olivia Newton-John's "Physical" was at the top of the charts; if you were really cool, you were into roller disco; and Sony's Walkman had just appeared and was taking consumers by storm. It was in this environment that John C. Koss decided to jump on the portable audio bandwagon and produced the forerunner of the Porta Pro, called the "Koss Sound Partner" or KSP headphone, and a portable AM/FM radio called the "MusicBox."

Over the next couple of years, Koss continued to work on their designs and discovered they could improve on the KSP. From the Koss website "History of the Koss Porta Pro:"

"The Porta Pro transducer was designed to be assembled as a part of the ear cup assembly on its own pivoting ball and socket. A specially crafted ear plate was painstakingly developed to front load the transducers to optimize diaphragm excursion and limit distortion. Rear damping and specific resistance was accomplished through the creation of a series of tiny perforations molded into the element case and originally discovered in earlier engineering work in Koss electrostatic technology and computer optimization of acoustic performance with the Koss computer maximized loudspeaker systems introduced in the late 1970s. "

In 1984 the Koss Porta Pro was introduced. Now with it's new driver housing and "Comfort Zone" earpad pressure adjustment, the headphone was ready for prime time. It is truly a testament to these performance portables that they remain little changed today after all this time ... and that they remain strongly competitive long after cassettes and the Walkman have gone the way of the dodo. These are great little cans.

John Koss in the 1980's shows off the Porta Pro and stands on his head to demonstrate how secure they are on his head.

General Description
The Koss Porta Pro is a small earpad (on-ear), open (unsealed) headphone. Usually a sealed headphone is used for serious portable applications to cut down on external noise, so I would characterize these cans as light-duty, general purpose headphones rather than strictly portable headphones.

The physical design of these cans is quite unusual, and telling in that it was designed long before the wealth of headphones we see today. They are very obviously the result of innovation across the board, and developed without the context of an array of competitive products. Quite unique.

The headband is two simple metal bands in an arch to go over the head, which slide relative to each other to provide head size adjustment. This is a simple and effective mechanism, but can catch your hair from time to time.

The headband terminates in a plastic piece that acts as a "temple pad" and allows three settings of adjustment for how hard the earpad rests on the ear, called the Comfort Zone adjustments. This adjustment is spring loaded and won't remain in position when the headphones are removed. I felt that this adjustment is fairly useless as the headphones don't exert very much pressure on my ears when set at its firmest position, and the headphones sound best as they are more closely coupled to the ear.

A now-discontinued lower-cost version of these called the Porta Pro Jr. didn't have these adjustments, and I felt they were a real bargain at the time. There is now a low-cost version called the Sporta Pro, and a clip-on style called the KSC-75; both use the same driver and have very similar sonic qualities --- which are quite good.

Between the temple pad and the driver/earpad is what Koss calls the "ear plate." This is a small arm that changes its position with the Comfort Zone control. This arm folds inwards and up into the band area for storage. When folded up it reveals a small hook and loop on the undersides of the temple pads, which hook together and make the headphones into a very small package for transport and storage. I don't recall ever seeing another headphone with this type of design ... but it does work very well.

The earpad/driver is mounted to the ear plate using a balljoint, which provides ample swiveling to conform to the angle needed to lay flat on the outer ear.

Ergonomics and Comfort
The Porta Pro is a very light headphone weighing in at a mere 2 ounces. This headphone remains very securely in position on the head with very little clamping force due to it's amazingly light weight. Even at it's firmest setting, the earpads do not press hard on the ears, making these little cans easy to wear for extended periods of time.

The four foot "Y"-cord cable is just the right length for use with portable players and laptops, and is terminated in a fairly small 1/8" mini-plug, that should fit through the holes in most portable player/cellphone cases. The headphone does come with a 1/8" to 1/4" adapter

Koss Corporation
4129 North Port Washington Road
Milwaukee, Wisconsin 53212

Armaegis's picture

I've owned a pair of these, but I just couldn't get a comfortable fit. Just the way it rested against my ears, it produced a pinch or the hook would dig into the top of my ear and the discomfort was high enough that I couldn't focus on the music. I have a slightly oddly shaped head though.

DaveBSC's picture

Sennheiser also used to compete at this level with the even more portable PX100, but the new PX100-II is twice as expensive and I'm not sure its twice as good (or twice as good as the $30 street price Porta Pro.

Tyll Hertsens's picture

I agree with you 100%.

I find the PX 100-II a very good sounding headphone ( I think I prefer it over the Grado SR60), but it is basically twice the cost. I think it might be twice as good, but I don't really know what that means, so I can't say for sure. I can say for sure that either headphone is a great value ... for sure.

LFF's picture

Nice review and I agree with everything you said about these classic headphones. I think they are among the best alternative for those people who hate IEM's and are looking for a good, cheap headphone to use around the house or at work.

gorboman's picture

After watching your video, I finally gave the Porta Pro a test at Jaben store in Jakarta. I was expecting to be surprised by the real sound coming out of the porta pro, but it caught me off guard. The sounds are amazing!

However, I think it has too much bass for my taste and the kind of music I'm listening today (which is Skrillex's dubstep). I'll stick with my Sennheiser HD202 for dubstep for the time being.

Btw, Tyll, I guess you've got this question a lot: which do you recommend between the ATH M50, Solo SL150, or the SkullCandy Aviator?

tomasz's picture

Thank you for this review Tyll. I would like to present my own opinion on differences between Koss Porta Pro and Koss KSC-75. I mainly listen to good headphones in my home through headphone amps made by myself. But sometimes I like to listen to music outside home and only then I use Koss headphones with my mobile phone. I own both Porta Pro and KSC-75. I believe you Tyll that these two are made from the same driver, but in my opinion KSC-75 sounds much better: more natural and spacious, with much more clear mid-tones. I know this is very subjective, but discovery of KSC-75 was unbelievable for me. I heard so many headphones even 6-times more expensive that didn’t sound as good and I never heard any headphones that were as good and were so mobile. I don’t have such feelings toward the Porta Pro. So for me the differences between these two are profound and I highly recommend for everyone who consider Koss headphones to have a listen if that’s possible, because I personally feel KSC-75 are clearly better. I feel that Headroom recommendation for KSC-75 as one of 10 best headphones in the world is not an overstatement
I would only add that I listen only to classical music and my main headphones are HD650 and K702.

crazykiwi's picture

Sorry, know this is a really old post but I was just comparing the KSC-75 and the Koss Pora Pro. Is there any chance that you like the KSC-75 more because the driver sits further from the ear rather than being pressed onto it. I find them to sound different also. However when I put HD414 pads on the Porta Pro which pushes the driver further from the ear the sound seems more similar.

InspectorLewis's picture

I have had these for 13 years now. Last weekend, carelessly, I vacummed them. The cables were pulled from the the actual earphone, BUT, it never snapped. They still sound wonderfully. I am not planning on getting a new pair of headphones. Of course, all my friends envy me. 

Also, great review, but for the sake of grammar: ITS = possessive. Ex.:  The Koss headphone produces great music. Its bass is tight.

IT'S= Contraction of it is. Ex.: The Koss company makes wonderful products. It's a great company. 

Sorry, I am a teacher and we read reviews for homework. 


Rivaldo's picture

My first Porta Pro was a false copy of the real one.

When I notice it was a false one, I buy a authentic Porta Pro and now  have both.

Well, I can tell your, Porta Pro is so good, which teh false one is excelent too, and barely dont have differency bettween both they, just some cosmetic things, like color of some  parts..