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Koss Pro4AA review

In this review, I’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, I’m curious to see how they hold up by today’s standards.

About the author

I’m a producer, audio engineer, and songwriter with a decade’s worth of experience with a wide range of gear and recording techniques. I have worked with and tested a huge variety of headphones, including Shure, Sennheiser, AKG, Beyerdynamic, Sony, and Yamaha, among others.

Koss Pro4AA headphones review
Image: Higher Hz

Final verdict on the Koss Pro4AA 2.0

I 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.

What I like

  • Affordable.
  • Well built.

What I don’t like

  • No bass.
  • Wonky treble.
  • Painfully uncomfortable.
Available at: Amazon

Power and frequency response 2.0

The Koss Pro4AA headphones 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 good studio headphones would sound. The best part of their performance is how weird and unnatural they make music sound.

Build quality 4.5

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.

Koss Pro4AA build and comfortability
Image: Higher Hz

Comfortability 1.0

Let me 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 3.0

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 3.5

It was hard to notice the outside world with these on, perhaps because it was next to impossible to comprehend what exactly it was I was hearing. Above average noise cancellation overall.

Accessories 1.0

The Koss Pro4AA headphones come with only themselves and perhaps a manual. No carrying case or extra cables or anything.

Koss Pro4AA headphones with accessories
Image: Higher Hz

Compared to other headphones

Here are a few alternatives to consider in comparison to the Koss Pro4AA. You can also check out my pick of the best cheap studio headphones to buy for $100 and $50.

Koss Pro4AA vs Audio-Technica ATH-M40x

Without getting too wrapped up in the details, I highly recommend the ATH-M40x over the Koss Pro4AA. They’re far more comfortable and natural-sounding in their performance.

Read the full Audio-Technica ATH-M40x review

Koss Pro4AA vs Yamaha HPH-MT5

The Yamaha HPH-MT5 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.

Read the full Yamaha HPH-MT5 review

Koss Pro4AA vs Shure SRH440

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.

Read the full Shure SRH440 review

Koss Pro4AA vs AKG K240 Studio

Again, the Koss Pro4AA are not the best option. The K240 Studio headphones are phenomenal for the price point in terms of sound, comfortability, and design. It’s really a no-brainer.

Read the full AKG K240 Studio review

Who are the Koss Pro4AA headphones 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.

Available at: Amazon

1 comment
  • No bass? No treble? Either your unit was compromised or your ears. Sure the headphone is bright and closer to a flat response than it is to the Harmann curve but it’s bass is *deep* and extends well and clearly into the 10hz range as advertized. It’s highs are present and clear as well. If anything it’s issue lie on it’s mids that are harsh souding and bright and lack definition (as well as it’s extreme disconfortable design and weight). In general it’s not a pair of cans that scream high fidelity, as I feel they lack the definition and separation, but they definately have their use case, I’ve found that it pairs great with vinyl records and 70’s music in general, who’d’ve guessed! First Review I see on this website and already highly disagree haha, will look up others of headphones I’m also familiar with (like the AKGs) as to not judge a book by it’s first page, but odd assessment nonetheless.