This full-size professional quality stereophone has long been the headphone of choice for broadcast and recording professionals whose careers demand reliable equipment and superior performance. As the first dynamic stereophone to deliver true full frequency, high-fidelity performance, the PRO4AA set the standard when it was introduced in its original form in 1970. In the late 1980s after long service, it was retired and replaced by a newer model. Customers clamored for its return, and by 1988 it was brought back by popular demand. Since then, though we've incorporated performance-enhancing technology and updated its style, the essence of the PRO4AA remains unchanged and it continues to set the standard for performance and reliability today.The PRO4AA features dynamic elements for an exceptionally wide frequency response from 10-25,000 Hz. Designed for frequent use over extended periods, the PRO4AA's durable steel and rubber headband is generously padded. Adjustable slide bars ensure a snug fit, also critical for hearing every note and keeping unwanted sounds out. The heavy-duty, single-entry ten-foot coiled cord affords ample flexibility of movement. It includes microphone mount hardware for complete versatility. The PRO4AA has a 6.3mm (1/4") plug and an 8 foot coiled cord.Whether you are a sound professional or simply love music, the PRO4AA will deliver excellent isolation, accurate sound reproduction, and the excitement of a live performance to your recording.

Titanium Coated High Polymer Titanium Diaphragm for Accurate Sound Reproduction

Oxygen Free Copper Voice Coils for Signal Clarity

Closed Ear Cushions for Maximum Bass and Isolation

Stereophones, with 3.5mm plug, and 6.3mm adaptor

Adjustable Slide Bars Ensure A Snug Fit

Closed Pneumalite Cushions Form A Positive, Comfortable Seal Around The Ears

Freq Resp: 10 Hz-25 Khz Imp: 250

Average Customer Review: ( 92 customer reviews )
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When I got these I loved them from the start. I never knew they made headphones that sound better than a quality stereo! The sound detail is excellent with audio CDs and MP3s, and the bass is strong but not overpowering. I haven't yet tried these out on DVDs, but I would imagine they would be awesome. As far as isolating goes, I don't know why you would need any type of noise-cancelling headphones (which sacrifice sound quality for technology), because with these babies on, all you hear is the music. My roommate has to throw something at me to get my attention when I have these on! For the newbies out there: these are not for use with a portable CD player or MP3 player; they fall far short of the amplifying power needed to push these phones. If you want something sensitive enough to use with a portable (look for something with impedence around 32 ohms as compared to 250 ohms for these) buy something from the Sennheiser line, as they are also lightweight. I use these mainly to listen to rock, rap, and R&B, with some classical here and there (when studying). These are ideal for the first three but the quality of the classical is not what I would imagine a "purist" would deem extraordinary.

The look and feel of these phones just exude confidence in the craftsmanship and the quality of parts. Simply put, these are some awesome looking headphones. The pads are comfortable but will stick to you in warmer weather. If you don't think you'll be able to handle two extra pounds on your head for an extended period, don't buy these. I only find slight discomfort in my neck after wearing these (and I wear them for 2-3 hours at a time). The 8-foot cord and 1/4" adapter provide ease of use while wheeling around a stereo or computer.

I would recommend these phones to anyone who wants some high-end headphones (from Koss, the people that basically created the headphone) for isolation or just overall excellent quality of sound, with a guarantee for the life of the product.

25 of 30 found the following review helpful:

Great sound, Nice design, not completely perfect.Nov 21, 2003
By Brian C.
Just got these phones last night & I am loving them. I bought them from amazon along with Blink 182's new album on the 18th. I got both items on the 20th! Great service.
Anyway, back to the phones. I pulled them out of the box, adjusted and then put them on. They look great and feel very comfortable. I have a fairly large head, but not the biggest. I dont think these phones would fit anyone much larger than me, I put them out to their largest setting. One reviewer said they were too heavy. They are going to be heavier than normal walking headphones, these are designed for studio and field recording. If you are looking to wear these all day to listen to your walkman, dont bother! While they are very comfortable, after an hour and a half or so of wearing them, your ears will get a bit hot. The cups fit very stug and dont leave much room for your skin to breath.
As for quality, I love these phones. While listening to the new Blink album I could pick up on every little detail, even a few mistakes! They are great for bass as well. The middle of the song 'Obvious' has a great low hit from a bas guitar which sounded great on these phones.
Cant forget to mention that these things are sexy!

9 of 9 found the following review helpful:

Awesome Sound...but heavyDec 12, 2005
By Mark E "the listener"
Bought them for the sound quality and lifetime warranty. After only one week of use I am pleased with the sound, but the weight of these is killing my neck. They do create a nice seal around my ears to block out noise, but my ears almost start sweating after and hour or so. Now, not to knock them too hard cause they are nice, but I have too big of a head for these. Fully extended the headpad still gives me a headache from resting and pressing up there. Great headphones for short listening periods and excellent sound quality, but just not fitting me right.

8 of 8 found the following review helpful:

Professional quality at an affordable price.Oct 25, 2005
By DJ Neal Money
I was a Club DJ for eight years and I've always used Koss headphones on the job and at home. This is my forth pair of Koss headphones, my first two pair lasted up until a year ago so I replaced them with the Pro4AAT and as a backup I purchased a pair of Koss R/80's. The sound quality of both are nothing less than superb. Koss also stands behind their product

with a lifetime warranty and will repair or replace your headphones for just the cost of shipping. There are plenty of high priced headphones on the market that claim to be for audiophiles and serious listeners, I've listened to a few and none can compare. Koss user for life.

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