Koss EQ50 3-Band Stereo Equalizer

I have the the older Koss EQ30 portable equalizer to help clean up the sound of my TV when run via headphones. It's pretty good, but over time has gotten some loose wires, and occasionally crackles. I would love a replacement but, sadly, that item is no longer available.

The new version, the EQ50, is a poor substitute. It relies too much on the strength of the source signal, and does not do a very good job. It works OK on some equipment, but still not as good as the earlier version. Plus, the EQ30 was more compact and easier to clip onto a short pocket. Why in the world Koss decided to discontinue a better product is baffling.

Probably best to keep looking.

Don't buy it.

Also, a lot of jacks with wide collars won't fit.

I'm always looking for that DEAL. Well, you know that old saying: You get what you pay for? (or a fool and his money......) Here it is, in all it's splender and glory. I wouldn't call it trash, or even the worst thing you could buy. Because in the real world, the Koss EQ50 could be used by someone with 60% hearing loss and love it. But, in sound evaluation, there's more Hiss here than what you can find between some AM stations. This little beauty isn't worth your time or money.

Just got this device today. I purchased it because my ZUNE does not have eq functions.

I used to work in recording studios so my ears are trained... I am not only familiar with what all different types of distortions sound like, but I also have a pretty good frequency spectrum recognition (trained by hours of playing with warble sine wave test tones and various parametric equalizers.) This is what I have to say about this unit...:

First of, the specification of this unit is 30hz - 20khz, but there is no tolerance indicated (+-db, THD, etc) so this number is pretty much garbage... The center frequencies of the graphic EQ are 125hz for bass, 1Khz for mid, and 10Khz for treble, with all bands adjustable +- 10 db. There is no information on the Q and bandwidth of the curves applied. The bass and treble bands are likely shelved, but I have yet to play any sine wave test tones through this unit so I cannot verify this.

This unit emits a hiss noticeable at approximately 10khz - 16Khz, which is why I suspect the treble EQ is shelved... This is not all bad or unacceptable for a unit this cheap...

However, I am not all that pleased with the choice of center frequency of the bass EQ. Most pop music sound much punchier with a boost of bass EQ centered around 50hz or so. I am not all that concerned with frequency below 40hz or so since all earphones by design cannot do an adequate job with bone conduction hearing anyway... Bass EQ centered at 150hz is way too high and makes modern pop recording sound bloated without the more satisfying lower notes. It makes a recording sound like those cheap boom boxes... I suspect KOSS chose this bass band center frequency to cater this device to ALL cheap headphones on the market, as increase of the lower tones will greatly distort headphones that cannot handle that kind of boost.

So if your expectation is very low, and your device does not provide any EQ at all (like the new ZUNE), then this unit will likely satisfy you. However, I do not think this device is of any use for devices that already have build in EQ functions. There are only 3 very coarse bands, the bass band center frequency is way off for any descent music listening, and there is small amount of noise (which is the least of the problems)...

I purchased this product to use in conjunction with my iPod as I have always felt the iTunes EQ lacks control. The Koss unit had a good range of boost and cut in the three provided bands, however it would have been nice if the bass band were centered at a lower frequency. As it is, the bass adjustment made the sound very "boomy" and did not enhance the low bass. This is a minor complaint when compared to the amount of "noise" this unit generates. The hiss on the output is tremendous, it over powers any advantage the EQ section provides. I was very disappointing as Koss in an excellent name in headphones and has been for years. I returned the unit to Amazon.com