I have owned a pair of Koss Pro 4X Plus headphones for twenty plus years and the sound is incredible! I thought I would 'upgrade' after reading so much about the Pro4AAT and could not have been more disappointed. These sounds just awful. I do professional restoration work for Casey Kasem on American Top 40 and sound quality is everything in what I do.

I concur with the complaints of other reviewers:

1. The bass completely lacks and sounds like a roll-off at 100 Hz and below.

2. The midrange is recessed and the highs are exaggerated. Overall the sound is harsh and brittle and really hollow.

I could only take about 5 minutes and have to say these are the worst sounding pair of headphones I have ever heard in my life. A TOTAL waste of almost $100.

As I said, the Pro 4X Plus has so much more dynamic range and response and I'll continue buying them up every time I see a pair come available.

Excellent audio quality for a good price! Very balanced in the whole frequency range. High tones are clearly reproduced, whereas the bass does not dominate. Can be recommended for all music lovers! It is worth its price.

after trying a few different open backed headphones i knew i had to have closed back phones. these koss pro4aat's are right for me. block out almost all ambient sound while delivering the music as you want it to sound.initially i found the sound muddy and booming-easily cured by turning bass levels down (not something i normally do!!) some reviewers find them heavy or hot on the ears-but not me. they also look good and are well made. you would have to spend a lot more money to get a better headphone.

These lasted me about 6 months before the plastic piece that holds the left earpiece on snapped into two pieces. They did get dropped quite regularly, but they broke one day when I took them off, I heard the sound of plastic snapping and the left earpiece was hanging by a wire not much thicker than a thread. I partially blame the fact that I dropped them so much as I do the fact that I have a large head.

Regardless considering how often these got dropped, they held up quite well for headphones these days. I have had plenty of headphones that did not hold up as long that I never got the chance dropped (mainly Sennheisers, they don't hold up at all) or broke the first time they were dropped from half the height.

The best part, is if you ask anyone who ever dealt with Koss before, they will tell you to ship them to Koss and Koss will replace them no questions asked for the price of shipping.

These headphones do sound quite good for the money. I'm very picky when it comes to sound, and these don't give me much to complain about. There is a slight drop offs in certain midrange frequencies, but other than that the sound is very balanced with clear highs, good bass and good low mids.

I would recommend the big brother of these headphones, the Koss Pro 4AAs to anyone considering these headphones or headphones in the $60-$150 price range. The sound quality is top notch and they are built like a tank and will withstand all the abuse you can throw at them. I currently own a new pair, and have used and abused an old pair for many years as kid (they still work but the foam on the headpiece has fallen off and pulls my hair out). Only downside is they are even heavier than the Pro 4AATs, but it has not been a problem for me.

I had a friend who owned some Koss UR20s, and they were awesome headphones. The bass response was good, they were THE most comfortable headphones I've ever worn, and they've lasted a good many years.

Contrasting this, I decided to "go all out" and buy some Pro4AATs. The statistics on the Pro4AAs were blowing the UR20s out, so I bought it.

I've been dissatisfied with my purchase ever since.

The Pro4AATs have mediocre bass response at best. The sound quality is thin. They weigh too much! I can't wear them for longer than an hour, because it presses down too hard on the top of my head.

3 years later, I'm still using these Pro4AAs, and my friend is still using his UR20s. I did a sound test, and the UR20s still wup up on the Pro4AAs.