[matt1039lp]

I just picked these up for my girlfriend as her christmas present.  They also came with the IEM pulse KEB40 as well for free
 
I own Sony mdr v6, Sennheiser 595, and Denon A2000.  I've got a Superpro 707 DAC and Total Airhead Amp.
 
Obviously my daily listening is with cans much better than these, however, first impressions are good!  They need burned in, but so far they seem pretty good, though they clamp a little too tight for me, though it's not a fair comparison with the 595s or A2000s as those are in another class.  For 50 dollars, they seem pretty decent. They do feel kind of cheap to me but what can you expect for $50.  I like that Koss has a lifetime warranty, which I've used on another set of headphones before and they replaced them with zero problems.
 
The bass on these suckers is very prominent in a good way.  The mids are quite a bit muffled right now...but we'll see how they sound after burning them in. Right now I dialed down the midbass hump and turned up the highs just a tad and they sound more pleasant to me, but that's personal preference.

 

[tdockweiler]

Believe it or not this is caused by the metal grill and the fabric behind it. I compared two different pairs of UR-55s. One with the grill and one without. I don't like to suggest removing the grill due to risk, but it's worth it 100%. It really does transform the headphone into something much better. It's soundstage when open is even better than my AKG k240 Studio!
 
UR-55 is really impressive when the grill is removed. It's really a fun sound signature and I prefer it over the KSC75 and Porta Pro.
 
Quote:

  The mids are quite a bit muffled right now...

 

[matt1039lp]

tdockweiler, thanks for the tip.  Actually I did see your review and mod as it seems that you are all over the internet talking up the UR55s (head-fi, amazon), haha.  The unfortunate thing is that you can't do the mod without losing the lifetime warranty and as these are a gift, I've got to let it remain as-is.
 

 

[tdockweiler]

Quote:

tdockweiler, thanks for the tip.  Actually I did see your review and mod as it seems that you are all over the internet talking up the UR55s (head-fi, amazon), haha.  The unfortunate thing is that you can't do the mod without losing the lifetime warranty and as these are a gift, I've got to let it remain as-is.
 

Yeah, I'm a huge fan of the latest two Koss 2010 headphones (DJ100 and UR55). Never was a huge fan of koss before that. Not since I had the TNT/55 (anyone know what driver that used?). I did post an amazon review of the UR-55 since I liked the headphone so much. DJ100 is the one that almost nearly turned me into a koss fanboy. Close, but not quite. Tried the UR-40, UR-29, Pro3AAT and Pro4aat but never liked those. Only older koss headphone i'm a fan of is the KSC75.  I guess what stinks is almost NOBODY here uses or has tried the DJ100 and UR-55 and that's just too bad. Maybe a few. DJ100 is so great to me it deserves much more attention.
 
I imagine removing the grill will void the warranty. It just seemed like Koss would have noticed what the poor grill design does for the sound. It's not awful with the grill installed, but the difference is enough for me to keep it removed.
 
 

 

[PhoenixJ]

Just ordered me a set of these on the advice in this thread, £25 (About $40?).
 
Looking forward to them! I need a set for work as my Grado SR60s aren't exactly suitable for the office environment.

 

[amfitontds]

very cheap plastic still there -- koss just not the same)

 

[tdockweiler]

Quote:

very cheap plastic still there -- koss just not the same)

Do you ever own these? The plastic is actually pretty good and even higher quality than the junk used on the HD-598.

 

[PhoenixJ]

Currently using these. Sound leakage has been totally exaggerated, my colleagues sat next to me say they cannot hear anything when listening to music at normal volume. Excellent sound for the price, very much worth it.

 

[mertz]

I have to agree. I demoed the UR55s a couple months ago and fell in love with them. I wouldn't say they are the most articulate or transparent cans in the world, but they do exactly what I like. The bass is full, deep and tight, but not bloated or overdone. The mids are clear but not harsh at all. The highs are slightly soft. You can still hear lots of detail, but it's not at all harsh or fatiguing. I really liked the sound over all. Kind of Gradoesque, but less fatiguing. For the price, they are incredible.

 

[mertz]

Any pics of the mod?

 

[germanium]

I just bought a set of these about 2 weeks ago. I find their sound considerably better than my Denon AH-D1001 earphones. The Denon's are very boomy sounding compared to the Koss's, The Denon's also have a very slight treble emphasis compared to the The Koss's. Both the earphones have an emphasis in the lower mids that make the sound very closed in though worse on the Denon's. Tdockweiler's mods does not get rid of this characteristic though it does improve things very very slightly. It's not a  night & day difference at all. The same type mod on the Grado SR-80 has a huge effect but not here. The lack of boominess on the Koss's is traced to not having any undamped holes in the back of the driver. All holes have damping material over them. The holes are large enough to allow for some incredibly low bass response for an open phone. The driver looks to be 50 to 55mm & is considerably larger than driver in the Denon's which is 40mm. Most phones have 1 undamped hole in the back of the driver & that is why I find most have boomy bass which detracts from all sounds above & below the resonance caused by this undamped hole
 
I consider these to be open phones as these leak sound both from the back & front. The earpads are open cell foam with what seams to have a calibrated leakage which combined with the well damped  large holes in the back of the driver produces excellent bass levels without boominess. I just wish they had a little more upper mid's & treble. What is there is very clean but could be more. There is definitely some emphasis from 500Hz down compared to above 500Hz. I slowly turned on some boost from 1KHz and above so there is 3db boost at 16KHz & they sound much better balanced. Similar EQ to the Denon's does not improve things as the sound is still closed in.
 
The Denon's are sealed phones which causes your ears to sweat & become uncomfortably hot over time. The Koss's open nature reduces this but not eliminates it. The Koss phones do squeeze your head tighter which for some people may find uncomfortable but I'm fine with that.

 

[germanium]

I just removed cloth over the front over front of the earspeaker & they sound much better balanced now with good extension at the top now. Much less closed in sound now. No need to boost frequencies over 500Hz now

 

[newphones]

Quote:

I just bought a set of these about 2 weeks ago. I find their sound considerably better than my Denon AH-D1001 earphones. The Denon's are very boomy sounding compared to the Koss's, The Denon's also have a very slight treble emphasis compared to the The Koss's. Both the earphones have an emphasis in the lower mids that make the sound very closed in though worse on the Denon's. Tdockweiler's mods does not get rid of this characteristic though it does improve things very very slightly. It's not a  night & day difference at all. The same type mod on the Grado SR-80 has a huge effect but not here. The lack of boominess on the Koss's is traced to not having any undamped holes in the back of the driver. All holes have damping material over them. The holes are large enough to allow for some incredibly low bass response for an open phone. The driver looks to be 50 to 55mm & is considerably larger than driver in the Denon's which is 40mm. Most phones have 1 undamped hole in the back of the driver & that is why I find most have boomy bass which detracts from all sounds above & below the resonance caused by this undamped hole
 
I consider these to be open phones as these leak sound both from the back & front. The earpads are open cell foam with what seams to have a calibrated leakage which combined with the well damped  large holes in the back of the driver produces excellent bass levels without boominess. I just wish they had a little more upper mid's & treble. What is there is very clean but could be more. There is definitely some emphasis from 500Hz down compared to above 500Hz. I slowly turned on some boost from 1KHz and above so there is 3db boost at 16KHz & they sound much better balanced. Similar EQ to the Denon's does not improve things as the sound is still closed in.
 
The Denon's are sealed phones which causes your ears to sweat & become uncomfortably hot over time. The Koss's open nature reduces this but not eliminates it. The Koss phones do squeeze your head tighter which for some people may find uncomfortable but I'm fine with that.

 
Very interesting write up. Thanks.

 

[germanium]

Been doing some more listening & comparing them with the Denon AD-D1001. The Koss UR55 are definitely superior in all aspects now compared to the Denons. These could definitely be used in a studio monitor situation. Their frequency response though still a little bass heavy are balanced well enough & are smoother in response than some other well regarded "studio monitor" earphones. Compared to the Denon's I have With the mod to the Koss's they have the same sparkle in the treble as the denons but with more body making the cymbals sound more real than they sound on the Denon's . It's a smoother sweeter sound, less tizzy sounding treble. Same with the mids & bass. Sound is just more even than the Denon's throughout. The Denon's don't sound bad until you hear the UR55 in all it's glory. Out of the box you get a somewhat good impression but nothing compared to what awaits you when modded.
 
The most important part of the mod is removing the cloth from the front side of the driver as this really balances the sound out nicely. The back side mods are much more subtle in effect. A very slight opening of sound stage but nothing to write home about. The front side mod is much more effective than the backside mods at opening the soundstage up as it creates the proper frequency response in order to extract the soundstage information.

 

[tdockweiler]

^ You're really making me want to get another pair. At one point I had two pairs and was A/Bing them with mods. I also liked how they sounded when removing the grill fabric. It's a bit tricky without knowing how to get the pads off. They just peel off sort of.
$25 for these on Amazon is a good deal. I remember paying $50 for mine when they first came out as a Best Buy exclusive.
 
When modded they work very well for a cheap gaming headphone too.
 
The only negative is that they're not crystal clear, but for $30, who cares? The mod helps somewhat with that.
 
Have you tried the UR-22v yet? You should..works with M50, V6 and Pearstone velour pads. Only $18 too. They're at nearly every Wal-Mart. Too bad there is a ton of clamp.