Today, we’ll be taking a stab at the Koss Pro4AA closed-back headphones and comparing them against some modern competitors.
Designed and originally released in the early 70s, we’re curious to see how they hold up by today’s standards.

Our verdict on the Koss Pro4AA
We understand that these are incredibly affordable, but you don’t get much out of the expense.
The Koss Pro4AA deliver next to nothing in terms of high-fidelity, as they are lacking in both bass and treble. They’re also extremely uncomfortable and will need to be modified for any semblance of practicality to shine through.
If you’re curious to know what it would be like to produce music in the stone age, go and pick up a pair.
Check priceAmazon.comPower and frequency response
The Koss Pro4AA have a frequency of 10 Hz – 25 kHz and an impedance of 250 ohms. However, these headphones are lacking in just about everything that is high-fidelity.
The low end is fairly flat until rolling off at around 60 – 80 Hz. In general, the bass is incredibly lacking. Any “thump” is perceived more as a “click”, and all sense of texture is gone.
The midrange is incredibly flat, and fairly detailed. It adds no extra clarity of definition to vocals or lead guitars, but nothing is recessed. This is more or less the same until the frequency response starts to glide upwards around 1 kHz, finally resting upon 2.5 kHz.
These may be the closest one can find for a one-note pair of headphones, because right after this jarring resonance, the frequency response rolls off almost immediately – albeit with a few more wonky peaks and valleys.
Overall, these headphones sound like the opposite of how a good headphone would sound. The best part of their performance is how weird and unnatural they make music sound.
Build quality
Considering that the design of the Pro4AA is primarily made up of thick and heavy plastic, as well as metal, these things were built to last.
The vintage models of the Koss Pro4AA floating around should serve as a good indicator of how well these were built.
They are extremely heavy though, and may induce some neck strain.

Comfortability
Let us just say that these headphones are not only uncomfortable, but rather painful to wear. The weight is poorly distributed, they’re insanely heavy, and they squeeze your head.
The padding is very thin foam, which is the only thing separating your ears from the plastic grille over the drivers. A thin rope netting glued to the foam will cut into your ears.
You can save yourself some pain by resorting to a paper towel mod without affecting the tonality too much, but that’s about it.
Overall, one of the worst feeling headphones around.
Stability
They may stay on your head for a while, although you probably won’t like it. Don’t take them for a jog either, the sheer weight of them will most likely cause you to trip and fall.
Noise cancellation and isolation
It was hard to notice the outside world with these on, perhaps because it was next to impossible to comprehend what exactly it was we were hearing. Above average noise cancellation overall.
Accessories
The Koss Pro4AA come with only themselves and perhaps a manual. No carrying case or extra cables or anything.

Compared to other headphones
Here are a few alternatives to consider in comparison to the Koss Pro4AA.
Koss Pro4AA vs. Audio-Technica ATH-M30x
Without getting too wrapped up in the details, we highly recommend the ATH-M30x over the Koss Pro4AA. They’re far more comfortable and natural sounding in their performance.
Koss Pro4AA vs. Yamaha HPH-100
The Yamaha HPH-100 are an outstanding choice for musicians on a budget. They’re not the most comfortable but are much better to wear than the Koss headphones.
Koss Pro4AA vs. Shure SRH240A
While you can’t expect a budget pair of headphones to sound as great as higher end models do, these blow the Koss Pro4AA out of the water in terms of both their sound and comfortability.
Koss Pro4AA vs. AKG K240 Studio
Again, the Koss Pro4AA are not the best option. The AKG K240 Studio are phenomenal for the price point in terms of sound, comfortability, and design. It’s really a no-brainer.
Check out our full AKG K240 Studio review
You can also check our recommendations for the best cheap studio headphones you can buy under $100 and $50.
Who are the Koss Pro4AA best suited for?
If you’re an engineer curious to see what it would be like to work with headphones from the 1970s, the Koss Pro4AA are a perfect match for your niche and interest.
By today’s standards, they aren’t of much use. However, if that’s what you’re after – go for it.
- Affordable.
- Well built.
- No bass.
- Wonky treble.
- Painfully uncomfortable.