Summary: Bestest headphones ever. I must have had them nearly 40 years and they are as good as new! Once, one of the 'speakers' became loose so I sent them to Koss for repair - they did a full service - everything, new 'speakers', foams and cushions and at a very reasonable cost. That must have been 20 years ago!!! These are absolutely THE BEST!!!
Summary: When I order these, shall be my 4th set since about 1971-72. They have traveled with me through my time in the service, been moved a number of times around the country, in boxes/trunks/car-trunks. Only problems I've had is getting the oil-filled ear-pads replaced. Other than that, they REALLY shut out most outside noise, has full/rich bass response, magnificent overall sound.
Pros: Magnificent sound, very full range, massive bass response
Cons: They do weigh a bit more than most may care for.
Summary: I purchased my "AA's" in '72 and use them almost daily. I have gone through several sets of pads but other than that they are still the set I go to when I want to listen to music in a busy room. Someday I should swap the 1/4" phone plug for the current 1/8" I tried the expensive noise canceling brand but these are more comfortable and just a quiet; maybe more so.
Pros: Audio quality, construction
Cons: A little heavy but weight is well distributed
Summary: I used these phones from 1977 till 1987 and beyond. I assume the original owner still has them. They were used to record and mix tracks in our small studio along with some other types. These were the favorites. They isolated you from room noise and they didn't lie. For the money and considering their anvil-like construction it was a fine deal. I hope Koss still uses the same materials and methods..
Pros: Rugged, good sound, neutral, good isolation
Cons: Heavy, sonically flat, can be uncomfortable...
Summary: I had a pair of the Koss PRO 4/AAs and they had stopped working. Not only that, the coiled cord was no longer very coiled and the plastic headband part was coming apart. These were very old friends used for Ham Radio and stereo listening. After reading other reviews about how Koss stands behind their products, I went to their web site and followed their instructions. Sent them in with the $9 requested and two weeks later I get was it essentially a brand new headset.
Summary: I have owned multiple KOSS Pro 4/AA headphones over the years. The Original high power, high volume, super durable headphones from the 1970s - there is a reason they still make them. The Good: They provide good, solid, clear communications audio. Compared to audiophile headphones, and with most consumer grade headphones, they are a bit light on bass, which is ideal for communications grade audio. The high end is more than ample to the task.
Summary: I grew up with these headphones after my father bought them in the 1970's. They have been used, abused, and continued to perform flawlessly for decades! Over time the ear cups deflated, the foam headband was lost, and they began to collect dust in the basement until I heard about Koss's lifetime warranty. I sent them in 2 weeks ago, and for only the cost of shipping they cleaned them up, repaired the headband, replaced the ear cups, and installed new drivers and wire.
Pros: High quality, amazing warranty/customer service
Summary: I was very excited to use these in conjunction with my Old Sansui receiver and Yamaha CD player, and the first time I plugged in, I was shocked. Not by how good it sounded, though, rather how different it sounded. I've always had to tinker with EQ levels with other headphones (usually around Bass - 10 Treble - 8) and I immediately noticed alack of bass compared to what I was used to.
Pros: EXTREMELY Balanced
Cons: Weight, but doesn't really matter to me with this sound quality
Summary: I have used PRO4AA for about 15 years. The warranty has replaced the phones several times because the joints that hold the band together comes apart and have so many gluings before I send in for repair. Also the insulation on the cord after several years will crack to the point of needing replacing. As a licensed broadcast engineer, now retired, I need critical headphones that seal out the sound so that I can hear audio.