Summary

Ecellent headphones overall, but the mid bass boost is too much for me. (The HD-595 is better in this aspect)

The spatial sound field is incredible .... it's like the music is in your brain (I can't say it in a better way).

Strength

Warm yet uncolored.

Nice resolution .

Very comfortable to wear..... very very comfortable.

Replaceable cord and pads.

Weakness

Mid bass too boomy.

Customer Service:

Excellent. Real audio enthusiasts.

Summary

Solid highs, never fatiguing. Solid mids, no apparent dips or peaks (atleast to my ears). Solid bass extension and impact - perhaps not subwoofer-like, but good enough in the world of headphones. For the price, it is hard to beat the HD555. The HD595 are about $100 more, but the performance difference between the two is almost neglegible. The HD555 are a solid contender in the sub-$200 arena with a warm, balanced sound that can be somewhat forgiving to bad soundtracks. Although this may not be the most neutral phone, it certainly is warm, lush, and inviting. The HD555 are truly musical. One word - make sure to amp the sucker. Or atleast run ir from a receiver's headphone out to get the most out of it.

Strength

Balanced sound.

Weakness

Perhaps not the most neutral.

Summary

OK, so here's what they give you after over 200 hours of intensive burning in: Generally speaking, it's a nice, detailed and pretty well balanced sounding headphone. Now to be more specific. The harshness of the treble is pretty much gone. The highs got clear and crisp, they give you a lot of detail. They are not as smooth and natural as in the HD590, but then again - comparing the HD555 with high-end phones is a little unfair, considering the price. The bass. Surprisingly, it got a hell of a lot better after some 50 hours. It is very powerful, yet still natural. Almost. I doesn't reach as deep as I would like, but still blows away all floorstanding speakers under 700$. The mids got louder in time, causing the overall sound to be quite well balanced. They still lack the warmth of some higher class Sennheisers, however. But there's one important thing - the HD555's feature a new invention called the Surround Reflector. I have absolutely no idea what it is exactly, but it's something with the positioning of the drivers that causes the sound to be much more upfront. It's amazing how three-dimensional some recordings sound - you just think the singer is right there in front of you, with the band behind him. I have never heard an effect like this in any headphones without a 3D headphone amp like the Sennheiser Lucas/DSP Pro.

Strength

Amazingly three-dimensional sound stage, lots of detail, got quite comfy in time

Weakness

Still no warmth in the mids, lack of really deep bass

Summary

I bought these cans as an anniversary gift after only a short audition. Well, I really do hope they will perform better as soon as the burn in, because so far they're performing below my expectations. They lack detail in midrange, the treble is harsh and irritating, and the bass is overemphasized and lacks definition. They sounded a lot better and natural when connected to a Sennheiser headphone amp, but please - since when are dedicated amps a sine qua non for 100$ headphones? Another thing is the pressure on the ears. 3,5 N is waaay too much. Hope it gets weaker in time. I don't know what is happening to Sennheiser middle class. Five or six years ago they had good, versatile products in this price range. Then it started to get worse and worse. The HD570 model was a disaster with its total lack of midrange and this strange loudness effect. The HD555, which is supposed to replace it does sound warmer, but is still harsh and easily tires the ears. This review is based on the impressions of only the first hours. I think I will give another one after a couple of weeks, and I hope I will be able to give more stars by then.

Strength

still quite detailed, warm sound

Weakness

harsh treble, low quality and too strong bass, uncomfortable