Koss PortaPro - Headphones ( semi-open )

General Information

This high quality portable stereophone set performance and comfort standards for personal listening worldwide. Over the years, much to the delight of devout PortaPro enthusiasts, Koss has preserved the original design and performance that made the PortaPro a portable music icon. Today the PortaPro remains the headphone of choice for the discriminating listener.The PortaPro features dynamic elements that deliver exceptionally rich, deep bass and a remarkably wide frequency response from 15 - 25,000 Hz to capture every nuance in your favorite movie or musical performance. Constructed from mylar, the elements are extremely rigid, minimizing mechanical distortion and ensuring exceedingly accurate sound reproduction. Neodymium iron boron rare earth magnet structures enable the PortaPro to deliver greater volume so you can hear every note, even when competing against the sounds of a commuter train with a low-voltage MP3 or disc player. Oxygen free copper voice coils improve signal transmission and conduction for cleaner, clearer sound. Foam earcushions provide an open, hear-through sound that lets you keep in touch with your surroundings perfect to wear while running, at work, or while traveling. Whether you're listening at home or on the go, the PortaPro will bring the excitement of a live performance to any recording.

Latest reviews


100+ Head-Fier
Missing the Era of Walkmans?
Pros: Affordable
Light and Portable
Good Timbre
Warm Tonality
Fun Sound
Safe Tuning
Intimate Vocals
Cons: Unusual Headband
Somewhat Muddy
Not very technically capable
This full review is also posted at mobileaudiophile.com

Koss Porta Pro

Koss brand is kind of a legend among audiophiles. They were very popular during the golden age of Walkmans. Although much has changed in the music listening habits of people, Koss Headphones stayed on the scene due to their good sound and affordable prices. Porta Pro is the most famous and one of the oldest entries in their product line; a legend among the legends.

Koss Porta Pro


Without boring you too much, I don’t necessarily have a sound preference. I tend to enjoy different sound profiles as long as they do well what they intend to do. I’m not very sensitive to treble so I can enjoy the most notoriously bright headphones, however I’m somewhat sensitive to upper mids area. Please keep these in mind.

Built, Comfort, Trivia

Porta Pro, like the name implies, very light and portable, comes with a pouch and has a pretty complex headband for a portable on ear headphone. Headband has a comfort setting which changes clamp force and possibly sound a little. Also it has no memory of your choice of length or comfort setting. The headband may pull your hair when you try to adjust the headband length, but that’s not a big problem for me as I hear for the others. They don’t seal and isolate well. You can even call them open back or semi-open back headphones in this sense. Sound profile also confirms this claim.

Koss Porta Pro


These have a significant sub-bass roll off like most open back dynamic headphones. But the presence of the mid-bass hump makes you forget this absence, unless you are a “wub wub” addict. I am not. They are very dynamic in this sense and can punch pretty hard. Not very fast, but I never felt ends of tones lingered more than they need to.

Mids are warm, lush, somewhat muddy, if you compare to more neutral or technically correct headphones. Frequency Response Graph may suggest otherwise, but vocals are really a strong point of Porta Pros. Somehow they come as intimate and very appealing, at least in lower frequencies, until 2k hz or so.

Koss Porta Pro

As you go higher frequencies, Porta Pro insists on staying warm and maybe dark, of course again if you compare it to more neutral headphones. They are relaxed, smooth and easy to listen to. Treble does not extends too high, which is again contributes to the relaxed tone.

About the timbre, this is I think where the Koss headphones shine. Porta Pro has a warm tonality but nothing sounds weird or off. Every voice come as natural. They have a very fun sound which is not fatiguing in any way. They don’t extend too well in the highs. Soundstage and imaging are average. These are not very technical headphones per se. But tonally very well balanced which is not expected in this price range.

Koss Porta Pro


I like Koss Porta Pro headphones a lot. If I don’t like something, I immediately sell them but these are mine and here to stay. Maybe I don’t give them much time. After all, I have lots of headphones and IEMs, most of them are more expensive and capable than these. But I still sometimes take them with me when I go out to grab some groceries. They are very comfortable and portable. And their presentation is like a window to the vast audiophile world. Intimate vocals and impactful bass is a delight. If you need an affordable and decent pair of headphones or don’t want to take your expensive pairs out, give Koss Porta Pro a listen.


500+ Head-Fier
Pros: Very punchy and fun; non-aggressive
Cons: none at this price point.
Over the years I've acquired more than a few keyboards, CM, ducky, DAS, you name it. Guess which one's my daily driver? IBM Model M. It's turning 31 this year, but its every bit as good as its modern siblings. In my headphone collection I have HE6, LCD2 Rev.1, HD600 and Porta Pros. Guess which gets the most head time? Porta Pros.

Switching back to porta pros from any other headphones feels like going home. It's a sound signature I'm familiar with, and I can very comfortably sit down for hours with these on my head. Okay u say, where's the subbass? Missing. Where's the treble? Muffled, completely cut off above 10K. None of other headphones in my collection exhibit these problems, but none of them gets this much love.

There is a reason why portapro remains popular after 3 decades. It's non-offensive nature, its powerful mid-bass, its mids. There are a list of things I can say about PortaPros but let's not forget its a headphone engineered 3 decades ago, and it unmistakably exhibits that kind of sound you'd expect from the 90s.

None offensive in nature, yet highly dynamic and engaging. Porta Pro has that sort of power that sucks you into music without thinking about gears or anything audio related. I can definitely notice the missing subbass switching back and forth between these and LCD2s, the endless treble extension of HE6 also put these to shame. But the mid is among the most life-like I've ever heard. It's very muffled yet highly realistic. It conveys the emotion even Utopia fails to bring out, and romanticize it 1000 times more. There you go. A sound addictive like no other. Adding sub-bass or treble extension would kill portapros, cuz that's what makes them unique. I use them every day for more than 8 hours since I first bought em in 2002, and if u ask me to keep only one headphone, this is the one. It happens to be the cheapest one, but over the years it has proven itself to be the most loyal companion. My one and only safe house. To anyone out there who wants to buy one, don't be fooled by its price tag. There're only two headphones that'll drive you to tears: Orpheus and PortaPro.


100+ Head-Fier
Pros: Great sound clarity and details, lightweight, comfortable, punchy bass, lifetime warranty
Cons: Old looking design, headband that will rip off your hair, leak sound in and out, not quality cable
These headphones are well known for its low price and quality. I think they should be called shockers because when you look at them its one thing but when you listen to them suddenly they change to the most expansive cans you can get :)  Sounds is really impressive, something you must try. 
Overall great headphones. I actually prefer the design of Sporta Pro not Porta Pro... I had both so I took speakers from Porta Pro which are better and got them into the Sporta Pro headband which looks cooler. I also put double pads on both sides so they are a lot more comfortable. These are great for travelling where you dont have much space to take them with as they fold into pretty small compact size.
Koss should really reconsider to change the design of these as the headband could be done better way, they could try to make a closed version of these, replaceable cable and maybe rotating cups then they could seriously compete with HD25 from Sennheiser. The fact they do leak sound in and out makes them difficult to use outside which I find the biggest issue with these. Forgot to mention the cable quality should be improved too as it intend to break when you wearing them outside due to the hot / cold weather. This happens to all of them and I have 3 pairs.
I always wanted to try some other models from Koss but haven't had the chance.
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