Sennheiser HD 555 Headphones

I happened to get these cans for $55 at that price I'd say they're well worth it. I preformed the foam mod about 10 minutes ago and, yes, I certainly noticed a difference. They've opened up a bit. My $55 purchase just became a greater value.
 
This is my first pair of audiophile headphones, and, unfortunately for my bank account, not the last.
 
put simply, if you're on a budget and need some good cans at a good price, these will be your huckleberry.

 Not much to say in this review. These are a great set of headphones for the price, they sound good straight out the box but great after being burnt in. The 'foam mod' makes these better again, essentially turns them into a pair of HD 595's which is great for the money. Good treble and mids but the bass can be a little muddy and drown out certain aspects of the music, one cause of this is probably my xonar sound card.

This is my first review here, so I thought it'd be on my first pair of Audiophile headphones.  After getting these things, I almost immediately found this forum and did the foam mod.  It sounded better, and that's when I got hooked.  I then adventured and did the soundstage mod and it made these sound even better.  At 6 months usage, these headphones are very nice for the price.  I can't imagine what higher priced phones must sound like, but I don't want to know so I am stopping with these phones.  They are more than enough clarity for my games, music, movies on my computer.  I am thinking about adding a small amp but I am unsure yet, doing more research first.

The hd 555 is good but not perfect

My ratings says them all. You can easily find much better hps than this one but for a lot more money. The sound is decent but lacks bass and clarity and the highs are pretty non existent. The level of detail is pretty bad. They probably sound better on a decent amp ( i have only a xonar Dx now). The best thing on this hp is the comfort and this is a big plus for me as i wear them 8-9 hours a day minimum. I skype a lot and play. Maybe i am to harsh to them but i really want more from my music.

I really like this pair of headphones. I bought them as my first "good" pair of headphones and now I'm addicted. I cannot go back to muddled base and blown out highs. If you're looking for a solid introduction to excellent headphones I don't think you can go wrong with these.

I personally wouldn't buy these again now (that I know more about audio) than $75 new. However, these are my first headphones, and I have some sentimental attachments to them. I actually prefer these to my HE-5/EF-5 currently, though unfortunately it is down and I can't do a perfect A/B comparison for now.

I wouldn't recommend anyone to get these now, but these were the first phones I toted to school and convinced three of my friends to purchase decent audio. All of them have gotten Senns (two of them with the HD555s - one used, the other I will sell mine to, the other with a very similar PC 350, which is probably not any better, unfortunately). I do hope that they will also eventually move on and see even further up the chain, not necessarily relegated to Sennheiser's offerings (not an insult to these, I love them).
 
SQ wise, they do everything I need them to. Easy to drive, without fatiguing bass, though I'd prefer to have some more isolation for portable listening (will try ES-10s as the sole HP for both home and portable, though there is a good chance that may not work too).
 
In a nutshell, they have good SQ for the price, but they aren't the creme of the crop any more at the price range. However, I've had extremely positive experiences with comfort and build quality. These are supremely comfortable and I don't even notice them on much of the time. I leave them always even when I'm not playing anything. The velvety-like pads are also great for a slight bit of insulation on a cold day (though on the flipside, they are bad in heat over 28-30C, though that is infrequent in Vancouver, Canada).

They also appear to be indestructible to me. Throw in a few hundred hours of moderate to extreme rain, much use both indoors and out, being dropped several dozens of times, slammed, dropped from relatively high perches, hitting concrete and other hard surfaces, having its gold plated connector bent out of shape half a dozen times, and still working strong - that is simply incredible. Not everyone has had such a positive experience in this department, but I absolutely adore them for this and they will always hold sentimental value to me. I hope the future owner of my pair of HD 555s treats and enjoys them well.
 

Edit: For the purchase date, I believe I bought it in May 2008, give or take a month. Also edited ratings a bit to be a bit more fair.
 
Edit 2: A lot of owners complain about issues with build quality, which is another reason why I would never suggest anyone to buy these phones now, with better options for whatever use you may have for these unless you can get these for under $100, preferably in the 70s range. However, the unsatisfied are always the more vocal bunch, and this has been perfect for me in my 2 years of extreme abuse (no kidding).

Edit 3: A (possibly) final append to my review - despite the low impedance and high sensitivity, these are NOT the definition of easy to drive. Yes, they are very easy to drive at home, and both my Auzentech X-Fi Prelude & Nuforce uDac will drive them to their potential, but they will NOT sound good straight out of an iPod or DAP (in my case, a Cowon S9) [Actually, the uDac does a much better job, as the Prelude botches the bass, has worse separation and sounds more veiled and muddy]. Look for phones made specifically for portable in this case - a 3 M cable, a 1/4" to 1/8" adapter plus sub-optimal sound quality overall is atrocious for outside usage, not to mention excessive sound bleeding and nearly no isolation (they're open cans, after all). ES-10s, in contrast, are excellent even when driven straight out of a DAP with no external (even portable) amplification or DAP, and I actually prefer the sound signature out of my S9 over my uDac.
 
ES10s of course, also do benefit greatly from superior amplification.

I will not write some looong review. Just things I noticed with my HD 555.
 
They need pretty long burn-in. But its worth it. You need decent audio source to get some quality from them. Headphone amp is not mandatory, but definetly helps. If you want, you can use iPod with them, it sounds pretty good, but it will eat your battery pretty fast. They are also suitable for using with PC. Which means they are fine with soundcards like ASUS Xonar STX or Auzentech X-Fi Forte 7.1 and Bravura 7.1.
 
Audio characteristic is kinda suprising, cause they are very neutral (at least to my ears). I had HD 650, which are far from being neutral (but they are fun) and AKG 701, which has those nice high pitched sound that will remove your brain from skull if you use them too long (curable by proper amp).
 
Those have nothing of this "qualities". They simply sound like they should. Maybe bit more emphasis on bass, not exactly briliant mids, and I find highs quite nice (though, HD 650 actually have better ones, but they should considering price).
 
Only real downside is build quality, after year they tend to crack where headband is attached to driver part. It will eventualy crack completely and fell apart. Its fixable, but it shouldnt be this way.
 
One of main "pros" is that they are comfortable. You can wear them for hours, even half day and you wont even notice them. I think that only HD 800 are such comfortable things (probably only way you can compare them to HD 800 ).
 
Thats all, if you want Sennheiser for some all-around activity (I suggest listening music on PC, iPod, or gaming) its good choice. HD 595 are similar, just have bit "crisper/clearer" sound.
 
Yea and if you want to game on PC and use 3D sound effects, you should buy ASUS soundcard, as Creative CMSS 3D doesnt work too much with this (it works best with closed cans, not open ones).
 
PS: "Sound reflector" is piece of tape-foam inside headphones, google out how to remove it and do it. (its easy and safe as long as you dont drop anything inside drivers, metal screws for example are very bad idea). If you leave that foam there, you will be tired fast from listening and sound clarity will be much worse than it should be. But please, be careful while doing this "mod" and dont destroy your headphones.
 
EDIT (14.1.2015) : After using quite a lot of another headphones, I will give HD 555 one more star. They are far better then they should be. Recently I came back from DT880 to my repaired HD555 (cause one driver in DT880 is either dead or half-dead). And I was absolutely stunned how much clearer HD 555 sound is. DT880 sound much smoother, more "melodical" you might say, but clarity like in HD 555 isnt there (neither accuracy I suspect).
 
Also small bonus for all HD 555 / Foobar 2K users in link. Its profile for HD 555 for Graphic Equalizer of Foobar2K. Im using it with Asus Xonar Essence STX. For me, it sounds nice.. try if you want.
 
https://www.dropbox.com/s/v8t1uoa8tgzsn2l/HD555.xgeq?dl=0