I really like Sennheiser HD25, the sound is very detailed and balanced. I love the sound isolation which is I think the best from within all other closed headphones. They are very light and small which is great. The design would be superb if the cups could rotate 90 degrees but they cannot. I especially like that every single part is replaceable which I think is the reason why so many people buy these. 
You dont want to spend too much and be forced to throw them away or pay for expensive repair after couple of years. 
 
I would wear them in public but I dont like that the headband is sticking a bit outside from the cups which makes them wider than they are. Small design changes would bring these headphones back to the #1 position. 
 
So many times these headphones simply crush anything else around them in terms of sound quality. They are precise, detailed and well balanced. The bass is nice and punchy but I would prefer if it could go slightly deeper. But dont worry its still deeper than most of the headphones within this price range. They are very loud which is another reason why other djs and professionals buying these. If you like them then do not hesitate as I dont think you find better on ear headphones. Yes, maybe Beyerdynamics DT1350 but for some reason I dont think they are so cool than these are. 
 
If the soundstage would be slightly bigger that would be fantastic as comparing to the other headphones they might sound a bit in your face. These are great for work such mixing, editing, mastering etc. Specially if you use them in noisy environment. 
 
When I search for new headphones I often use the term I look for something like HD25 but around the ear  Definitely wear them / check them in terms of the comfort before you purchase. 

No introduction is needed for this pair. The "rumours" about the sound quality are true. Some people disagree that they are good for music production, but I am not using them for this reason, so I cannot comment on that. When I am listening to music I prefer it to come to my ears as the musicians and sound engineers intended to, and I think that these headphones are doing it to a great extent.
 
Some people also find them to be uncomfortable. Well, they are not as comfortable as HD 598 for example, but this is to be expected from a closed-back pair. I would not expect more comfort than what they give. I'd describe my head as medium size, so people with large heads may find them a bit more uncomfortable.
 
Overall, very, very highly recommended!

 

Specs​

 

I've owned 2 pairs of these headphones over the past 10 years so feel I've gotten to know them pretty well. Apart from the cheaper SP version these are the only decent headphones above a budget level that I've really tried.
 
Looks
 
I don't think this headphone is for the fashion conscious but they do have a cool look of its own in an industry standard geeky DJ kind of a way.
 
Durability
 
This is a mixed bag for me although maybe it is harsh to complain about a pair of headphones that last so long. Overall they are pretty indestructible and I regularly take them to the gym and put them in there and take them everywhere without a second thought. You don't need to treat them nicely for fear they will break. I've never had any problems with the headbands or drivers. However there is a fundamental design flaw with this product that has occurred with both of my units and is well documented by other users. After a while (often many years) one of the cups will develop issues with intermittent sound requiring you to wiggle the connector cable to try to make it work again on a regular basis. The problem is that the spring inside the ear cup which the headphone connector is placed inside become faulty. If it wasn't for this i'm pretty sure they would last forever which I doubt sennheiser would want - they want you to buy another set. I'm sure it could be easily remedied if they slightly altered the design. 
 
 
Replacement Parts
 
It's a positive that so much of the headphone is user replaceable. However, although readily available, they are also ridiculously expensive such as the £40 price tag for a new cable.
 
Comfort
 
There are definitely not the most comfortable headphones out of the box. They exert a significant amount of pressure on your ears although the do loosen up after a time and become comfortable. That coupled with their lightweight design does mean when they have broken in I do find the comfortable to wear for sustained periods. 
 
Impedance
 
These do go very loud when using a dj mixer, a sound card or my macbook pro laptop. When using portable devices such as android phones I find that they are only just loud enough for me so I need to push the gain of my music app to its maximum before distortion to get the level I desire. They are loud enough to use but I would prefer quite a bit more headroom so I would only half recommend them for portable devices. Something designed to be so portable and durable really should have been updated to be more compatible with phones and portable music players.
 
Sound
 
I do like the sound and they offer excellent isolation. They sound exciting but a bit harsh in the highs and boomy in the bass. They have almost a dark sound and sound very full and not at all tinny. I wouldn't call the neutral. They are great for djing especially since the kick is emphasised in the low mids but for producing I'm not convinced. When mixing with them I find I tend to end up with mixes that are dark in tone, overblown in the bass and quite dull and lifeless in the highs. I really find it hard to make informed decisions about what is happening in the low end and mix the bass and kick particularly. Maybe high end harshness is part of the problem that leaves me with dull mixes. 
 
Conclusion
 
I need to replace these now and I am tempted to get another pair because they are very versatile in that you can use them for djing, sport, sound design, and to a limited extent mixing. They are also durable, lightweight and comfortable after a while of breaking them in. However I can't help want more from them - a pair that are more comfortable from the outset, that I can reliably mix on and that don't develop a fault after so many years with the ear cup connectors. Maybe I should buy these for recreational/dj use and then another pair for mixing as I could end up disappointed trying to improve on them. 

Design/durability: They look professional. As for the build quality, these are certainly the most rugged headphones on the market. It is practically indestructible, and if a part comes to break it is possible just to replace the part itself (ear pads, cable, headband, you name it). They can be thrown in a bag and not be worried about. Designed to last a long time, if not a lifetime.
 
Fit/comfort: Average. Many complain about the clamping force of the HD25, but I find it to be okay after a few months using them. The headband becomes more loose and flexible, although it still has more pressure than on other headphones. Definitely not the most comfortable cans around, though.
 
Isolation: Among the best headphones when it comes to this aspect. They don't equal IEMs, but still have a superior isolation to most other headphones of its category. Good for outdoor use, even for air travel, unless you fly a very noisy turboprop.
 
Sound: Excellent, and still a reference despite the years. The sound signature of the HD25 is rather warm (V-shaped), and very revealing from bottom to top frequencies. The bass has a nice texture to it, and sounds fast and powerful. Mids are slightly recessed but they remain neutral, not colored. The treble is bright and slightly aggressive. Also, the HD25 have a good amount of energy in them, an almost dynamite-like punch that can handle any fast track. On the downside, soundstage is quite small although imaging is good. The HD25 provide an enjoyable, dynamic and polyvalent sound with a fair amount of details.
 
Bottom line: A classic that remains a classic, and a good bang for the buck guaranteed. Mine are 8 years old and still going strong.




HD-25 retrofitted with velour pads

My impressions is that these don’t sound significantly different than the cheaper SP version in terms of sound signature. The biggest difference is detail, more extended highs and smoother mid. If you didn’t like the SP version’s general sound you probably won’t like this either.

 

Comfort:
I personally don't like on-ear headphones that much because of sweat and heat reasons and this is no exception. These will keep my ears reasonably warm on a rainy day. Takes a little fiddling around to get a good seal. My ear gets warm over half an hour. The clamping force is just right, not loose or vice grip. 
 
Build:
Everyone says these are built like a tank and I agree. These headphones feel very solid and hard despite their plastic build. They will be able to withstand a good amount of abuse. I don’t suggest walking around with these in the rain though without an umbrella. Good headband construction. I like the two piece headband so it makes it easier for me to wear the headphone tilted back as the balance is better.
 
Isolation:
Not as good as my Westone IEMs but that is expected as these are on ears and not over the ears. If you’re a loud listener these are be ok on the bus or for walking around the city but for a really noisy subway train it might not be good enough as I found myself reaching for my IEMs.
 

High:

Sound somewhat rolled off. Cymbal hits decay fast. Snares sound a little thin and distant. As someone whose preferences are in a bright sound I would not say these headphones are bright as the HD558 sounds brighter to me and grados are far brighter than both. I would say in general these headphones don’t have any spike that would sound harsh; occasionally the upper range of female voices can sound a little scratchy and thin. I wouldn't listen to classical with these.

 

Mids are fairly forward even though it "sits behind" the bass often. Vocals sound quite close.  The mids sound smoother than the HD558 but in comparison it could sound more distant because of the bass presence. Male voices can sound nasally sometimes. I don’t hear any sibilance in voices. Midrange is pleasant to listen to most of the time, no harshness unless the recording was like that. HD25 does a lot good in this area with no glaring issues. 

 

Bass:

The midbass hump is prominent on every song and makes sounds sound warm. This can be good or bad depending on your preference. To me, it seems like the bass is the loudest part of all the whole frequency response. The mid bass is the body of the sound for these headphones. I notice it’s a little boomy as well.  These are good headphones for DJs as songs from deadmau5 or music in dubstep and trance genre will shine as the pacing of bass beat is very suited for these headphones. These are the headphones that your pop loving friend might like as well. Music with rhythmic repeating bass beats goes well with the HD25. Bass reaches depths that surprised me for the size of this headphone.

 

Soundstage:

Fair for a closed headphone, doesn't sound significantly wider or deeper than my Westone UM2. No artificial wideness or anything like that. I would not use these for gaming as pin pointing can be hard. I never get the feeling the sound is coming from outside my head but quite the opposite; the sound is coming from inside my head and stays there. A closed headphone like the ATH W1000 is much closer sounding to an open headphone than HD25 but that’s another discussion.

 

Detail:

Don't expect globs of micro detail but enough for enjoyment. You can hear nuisances but they are more blended in and again, the bass makes it harder to hear these small details. I wouldn't use these for mixing or for critical listening. Separation is reasonably acceptable but plucking of string instruments are not as distinct as grados for example.

 

These headphones are fun to listen to. If you are very critical of detail these are not for you. This is one of the closed back headphones everyone talks about so I figured I'd try it. These sound somewhat like Westone UM2 with a smoother midrange, more bass and midbass tossed in and less dry sounding. I will stick with my UM2 because I think the bass is a tad much for me but otherwise I can see why these are popular.

I'll make this clear - the sound signature of these headphones will not blow you away. I was expecting a lot from these (after reading the many positive reviews) and when i first listened to them i felt a little underwhelmed.
 
We've all had that experience where we listen to a piece of music and think...meh it's ok - and then months later you're putting in your top 10 all time favourite list. Well i've had the same experience with these cans. I have grown to love them!
 
 
Design - They're lightweight, surprisingly portable and have a minimal look and feel. They can be used as DJ headphones due to their tilt cup design (the left headphone can be tilted away from the ear). They are also modular which means you can replace the parts if they ever go wrong.
 
Comfort - At first these things did hurt my head and gave me a bit of ear ache when listening for long periods. However after about a month of use, the comfort significantly increased. The clamping force became much less intense and i can now wear them for many hours.
 
Sound Quality - As i've already mentioned, the audio quality will not blow you away. These are a neutral set of cans with an emphasis on detail and clarity. The sound stage is lacking and some tracks can sound a little flat. At first i thought this was a bad thing, but soon i began to appreciate the purity in the sound that these headphones offer. Give them high quality audio and you will hear every bit of detail. What puts the icing on the cake though is the instrument separation - this is what these headphones do best and at very high volumes too (i sometimes DJ in a club where the booth is ridiculously loud and no matter what the volume is - i can always make out the low, mid and high without any bleeding of the sound).
 
Bass - A little more emphasis here, but they never overwhelming and sound punchy rather than warm
Mid - Clear and neutral in texture
High - Clear without sounding bright (not fatiguing on the ears)
 
These headphones are great for electronic music (house, techno, tech-house) and sound great with older flavours too (trance, progressive etc.)
 
Value - Not that cheap and even though they're modular in design, the parts are pretty expensive. However these things are build like a tank, so in my opinion they justify the price tag.
 
 
9/10 - i absolutely love these headphones and recommend them to anyone who is looking for a closed back design.

I have own the Sennheiser HD 25-1 II for more than 6 years now, and everything is still in perfect condition. I have always love the analytical sound this unit delivers... These have turn to be my personal favorite headphones for tracking live instruments and recording vocals, but I use them to listen to music when traveling, and they are my favorite portable headphones as well.
 
They are not really that confortable, I find them to be a little uneasy to wear for long periods of time, but they isolate really well and sound great with theire slightly v shaped sound signature. I will recomend this headphones for anyone looking to something portable and with great sound isolation.

This is my reference for what a portable closed headphone should be.
It's neutral and sounds good on all genres.
It's not a giant killer like the DT531, but keep in mind it is closed and portable and has the most durable build quality of anything I've seen.
Also, it has the cheapest, most cost effective upgrade available for it, the upgrade to an HD650 cable.

In my opinion it is the second best deal to be had in headphones for a beginner to this hobby, second only to the Beyerdynamic DT531, if you can find it.
The Beyerdynamic DT531 has better high range sparkle and soundstage, but less midrange realism, depending on the genre you're listening to.
Anyways, neither are a perfect headphone, and calling either a giant killer is an exaggeration.
What I mean by that is for someone new to the hobby, the Beyerdynamic DT531 and Senn HD25-1 are just an amazing deal in terms of price: performance ratio.
Yes they are bested by even mid-fi headphones in the $600 range. But considering the price you can find these for used, I'm not sure I'd recommend someone to 'upgrade'  and spend 500$+ an amp if they're happy with the sound.

Listening to John Coltrane - A Love Supreme I preferred the HD25-1 to my HD650 balanced system powered by a Beta 22/Lavry DA10.
The HD25-1 has a seriously sweet midrange for being as neutral as it is. Tonally accurate, yet easily heard in the music, almost 'highlighted'.
This mysterious midrange quality is it's greatest strength and the most stand-out part of the headphone followed immediately by it's tight, tuneful base.

Now for the negative part. Over time the closed in soundstage makes them less fun to listen to. It kind of builds on you over time and threatens to distract you completely from the listening experience.
But if you listen while doing other things, like snowboarding or skateboarding, biking, you don't notice this.

That's all I really have to say for negatives. For the right person, these are the ultimate portable and rugged, yet amazing sounding headphones.
If they redesigned the arc assembly so that the headphones folded outward when sitting on your neck, we'd have a new FOTM (flavour of the month) on head-fi.

These headphones are clearly designed for DJs in dance clubs and I can't recommend them for general or casual use.  They get 3 stars for doing what they're designed to do well enough but could be much better.
 
They are very isolating as a result of a strong clamping force that crushes my ears to the point of pain after 10-15 minutes.
 
The sound is very forward and punchy.  Good for techno/dance but lacks refinement, subtlety and space.
 
They are overly bright and there's a treble peak that causes sibilance and is very unattractive.  Though I didn't use a high quality amp this peak seems to be recognised in frequency response charts and other reviews here that state they can be too bright.  I'm not sure if this is a deliberate decision so that DJs will tend towards making club music darker but it could well be.
 
If using an iPhone or low-power analogue out you'll need to use a treble reducer or custom EQ to even listen to these without serious fatigue and pain, though bass response without amplification is still decent.
 
Overall these have a very specific application and purpose and unless you're a DJ that needs high isolation and a "club" sound you should steer clear.

Summary: These headphones give an accurate picture of what the producers had in mind when they mixed their music because they have a well-balanced, present, but not over-powering bass.
 
Songs Used for Listening/Critiquing:

1. Stuck on You - Michiko
2. Unlike Any Other - Jeremy Ellis
3. Garden - Totally Enormous Extinct Dinosaurs
4. Basically, **** You - Deru
5. Flashlight - Parliament
6. Creator - Santigold
7. Petrified - Fort Minor
8. Jamba - Tyler, the Creator
9. Ballad of NGB - Stateless
10. I'll Never Leave You - Rogue Wave
11. BloodStream - Quartet Session - Stateless
12. Blue Ridge Mountains - Fleet Foxes
13. Sunburn - Muse
14. Rhino - Solander

 
I know that headphones are truly the best consumer audio market right now, and that's cuz I said so.
 
Just kidding.
 
But seriously, not a day goes by where I don't see at least 250+ people with headphones or earbuds on their heads, listening to these ridiculously leaky headphones that tell me more about their music taste than anything else.
 
Firstly, I think these headphones are quite something else. I can't put my finger on it exactly, but I know that they are amazing. Honestly, words can't describe the satisfaction these headphones bring to the table. I don't think I could describe the sound quite like others do (spacious soundstage, sweet treble, warm mids, supported bass, etc). On a side not, I work in the food industry, specifically coffee, and every day I have to work with coffee from Intelligentsia, people who describe their products with fluffy descriptive, pastoral, and picturesque diction and abstract syntax; I am not that kind of guy. I prefer to describe everything simply and with ease of understanding, so here goes.
 
These headphones are good. They get the job done. They are utilitarian. They are affordable. They are the PERFECT consumer product because they do everything that a consumer needs.
 
I own a pair of Sennheiser HD595's as well as Ultimate Ears Triple Hi Fi 10v (or something like that). I have also listened to the Senn. HD598, HiFi Man 500s, the Senn. OCX800, and a variety of Beats, Monsters, and other things. Of those, the HD598, HiFiman, and the Ultimate Ears were my favorite because they had noticeable clarity. They sounded good and didn't give me fatigue. I'm sure some have noticed that when listening to bad headphones, subconsciously or not, you get tired of listening to that music. I mean, if you listen trap music or like Blink 182, MUSE, and other high-gain songs that have massive compression and gain boost on the final mix, then duh of course you'll get fatigued, but I'm talking about Dave Brubeck, Kronos Quartet, and the Hilliard Ensemble. Listening to Stacey Kent's beautifully soft voice is tiresome when I have ****ty headphones on because those headphones don't sound natural, at all. The headphones that I liked were all natural-sounding headphones, with authentic sound that comes with quality engineering and technology.
 
Then come in the HD 25s. It is an amazing product because it sounds just like all the other headphones I listed above but with more bass. Why is that important? For me, it's very important; my mama always loved Earth, Wind, and Fire, Parliament, Chic, etc. and my dad loves Led Zeppelin, Deep Purple, Bread, America, Sultans of Swing, etc. My uncle loves Jimmy Hendrix, Beethoven, and Bach (weird mix right?), and I love electronica, rhythmic world music, and folk music. With all that exposure (and rest assured, I listen to all of those genres on all of my headphones, all day, every day), the one common factor between all of them, from Bob Marley to Aphex Twin, is bass. This is pretty obvious, considering the fact that bass notes hit harmonics with higher notes, immediately beefing up the overall density of sound that is produced. For example, when I was in a band and played one of my songs, I'd always incorporate a melodic bass line that runs against the upper register instruments (like the piano), and it never sounded thick or dense, but when the band played solid, unified chords, I was so astonished how much of a difference it made. This subtle, meticulous balance of bass and other frequencies is hard to accomplish, and that's where these headphones shine.
 
The bass on these headphones are not overpowering to the point where you can't hear other instruments, but they aren't thin like the HD595 to the point where Fleet Foxes sound wispy. They are perfect. They make the MUSIC sound BETTER. Now, I am not a pro audiologist, audiophile, whatever you wanna call it, but I can appreciate a well-balanced, supporting, not overwhelming, not nonexistent bass with a low range that goes all the way down to hit the sub-sonic frequencies in Tyler, the Creator's "Jamba," and these headphones are remarkable.
 
This is, again, my opinion however, and I think that is an important fact to consider. Some people like powerful bass, some don't, and I am neither of those, so consider my recommendation with a grain of salt. Furthermore, there is no such thing as "best" headphones; that's like saying there is such a thing like the "best" car, "best" steak, or whatever. It doesn't mean ****. Yet I can't help but appreciate how affordable these headphones are; they aren't, say, as cheap as some other headphones, but what you pay for and what you get is remarkable. On top of that, maintenance is super easy! Cables, ear cups, and other parts of the headphone are easily replaceable, a feature I love.
 
The worst part about these headphones? The looks. See, I think these headphones should be the standard headphone for everyday consumers; it gives accurate pictures of what the producers wanted to make in their labs, so you see an honest, untampered musical idea. Beats, for example, have a stronger emphasis on bass, and so every song will have a bass emphasis, even if the producer didn't want one. But they aren't pretty, and they aren't marketed well. They do really well with professionals, but I have such an itching to have my friends all listen to these side-by-side with their headphones just to open their "eyes" to what's out there. Clamp force is strong, but if adjusted well, it's fine (plus, a good seal on the ears = better bass).
 
Regardless, thanks for reading my ridiculously wordy, sarcastic, and boring review (just kidding, my reviews are the BEST). I recommend these headphones to anyone who's looking for something that is affordable, accurate, and eye-opening.

Happy Listening!

OK I've never reviewed headphones before but think that the Sennheiser HD 25-1 II are the perfect set to start out with, I really love these headphones, I think they look good and as for sound quality they are really great all round performers, great bottom end, good mids & good tops. I'm not gonna get technical with bright, dark, veiled, sibilant etc etc. I'm not good with all these terms, my ears tell me I like them, I wouldn't say they were sound perfection but I've yet to find a pair that could be described that way. I actually own/have owned many headphones, all of them have some kind of flaw. If I had to describe the flaw with these I would say they have a 'very slight screechy sound' but they do make up for it with their excellent sound quality & general performance, as I said before personally I think all headphones have some kind of flaw. I hope that my description doesn't put you of because I honestly think these are one of the better headphones available and out perform many at twice the price.
 
Nowadays I see more and more people wearing them in the streets & I think to myself these are people who care about how their music sounds, I got my first pair in the late 90's for DJ purposes, They are unbeatable. I've dropped them hundreds of times, the worst thing that ever happens is the ear-cups fall off, you just clip them back on again and your back in business, I've trodden on them more times than I care to remember, they've been literally ripped from my head when some fraggle went & got caught up in the cable (this has happened more than once). The cables are really strong. Durability wise these headphones are in a class of their own,
 
Comfort: They are tight but I wouldn't say excessive, they're not going to fall from your head, I always use them when I'm on my pushbike, safe in the knowledge that they are safe and secure. Sometimes I remove them for a few seconds to give my ears a break but in my opinion they're a comfortable fit, I like the way the headband separates, with a little bit of adjustment you will find the fit that's best for you.
 
As for portable audio once again I reiterate these are great headphones, they are of low enough impedance to perform well when plugged into an iPod. They are even better when plugged into an amp or my little Hisoundaudio Studio-V (DAP). Yes I do recommend them but I am biased because I totally am in love with them.
 
Bottom line... You can't go wrong with these headphones, they are highly sought after & have a high resell value, they make men look wise & women look sexy.

Sennheiser HD25-II is one of hot model in on-ear headphone. I buy it because of high rating from different users.
However, i feel very disappointed when I use it.
 
First of all, the headband structure is too tight. It makes my head painful and can't wear for more than 5 minutes, 1 song?!
 
Bass, quite strong
 
Mids - not natural
 
Highs - clear, but the highs are too aggressive. It hurts my ear when listening for long time.
 
I can't use it for more than 5 mins because of the headband pinching force. No matter how the sound is, the headphone is useless for a user if they can't use it daily.
 
Sorry about that. Sennheiser.

I'm pretty far from what I'd consider to be an audiophile.  I know that based on the extremes that people can go with this stuff that I'm never going to bring myself to justifying that kind of obsessive behavior, but I do believe in quality and performance and when you find something that works that the price is usually well worth it.  These headphones are the definition of money well spent.  I had bought blister pack junk in the $50-100 range for years with about every single year requiring replacement.  Not only did they not hold up, but they just never really sounded great.  I think that the sound quality has been discussed to death on these over the years as they are far from being a new product.  The only thing that I'll mention in that regard is that they are one of the most sensitive sets of headphones I've ever heard. When I was shopping for a "big boy" pair of cans I A/B'd every single headphone I could get my hands on and I discovered pretty early on that some of the higher end ones were going to require a dedicated headphone amp.  These do not.  I would be afraid to put an amp through these out of fear of blowing my ears out.  Portable, computers, etc., all drive these to insane volume levels with no problems and to me that means that their amps don't have to work as hard so I have less chance of distortion from overdriving the circuit. 
 
Perhaps I'm mistaken, but it makes sense to me.
 
The reason why I'm posting this "review" is because I recently replaced the cord on mine.  Now it wasn't that it wasn't working any longer, but I wanted a coily one so that I wouldn't be running over it with my chair anymore and I came across this place in my online search for a replacement.  It's funny because this was the place that I found when I was shopping for them the first time.  I thought that it would be cool to do a ten year trial period review. 
 
I've had to replace the earpads once.  I've replaced the cord with a coily copper one from Sennheiser.  Now I don't get all wrapped up in the oxygen free depleted uranium titanium shielded kevlar cable stuff, but I did notice a marked difference in sound quality.  Not massive, but noticeable.  While I'm sure some will argue that is because of the copper I honestly chalk it up to the fact that the other cable had been run over about 2 million times in the last decade by a chair containing my large backside.  I'd like to see how well you performed after that kind of abuse.  The fact that it still worked in the first place is amazing to be honest.
 
I'm not an occasional headphone user either.  I'd say that over the course of a month there is probably about 3 days in there that I don't use them.  I have never had a second's worth of problems with them in that time. 
 
Some people may not like the way they sound.  I love them, but everyone's taste is different.  But I don't think that I've ever owned anything as reliable and if you calculate the money that I spent on headphones prior to buying these I would have saved a few bucks if I had just bought these in the first place.  If you figure out the cost of replacing $50 clunkers over a ten year period it's not even worth considering.  I've not only enjoyed outstanding performance the last decade, but I've actually come out about $250 ahead in savings on garbage.  Subtract about $100 for replacement parts (pads and cable) and I still have $150 leftover and a pair of headphones that are still working as well as they did when I bought them ten years ago.  I don't think that I even have anything in my house that's ten years old anymore (besides my kid and his days are numbered). 
 
One of the best investments in anything I've ever made and I can't recommend them highly enough.

I love my HD25-1 II Headphones. They are, in my opinion the perfect portable headphone. I am not a huge fan of on-ear headphones but I do quite enjoy them. The sound quality is addicting, they are easily driven by an iPod or iPhone and have quite a bit of low end (perfect for modern electronic music), but when put on a proper amp the low end levels out the headphone becomes much more accurate.
 
The only real problem I see with them is they have quite a clamping force and when put on with glasses can become very uncomfortable. I use them for a max of 2 hours.

Being a non-professional, but a general music lover, My review will probably be in layman's terms, but why not. It will give the perspective from someone that observe music in a different way than the purely analytic fashion.
 
Once, I had a great home stereo consisting of NAD CD-player, amplifier and B&W speakers with some fancy cabling. -So I am not completely rookie regarding what sounds good and not. Neither am I a person that thinks that resonating boomboxes (cars) driving by is coolz because of lotz of basz. I like to hear all kinds of music. Anything from Mozart'ish music to music 'designed for serious PA-systems'.
 
Being without my stereo for the longest time and getting tired of the 'noise' rendered by my speakers integrated in the laptop, I figured out it was beyond due time to get myself some headphones. Getting a proper soundsystem is out of the question due to limited space and girlfriend.
 
First problem was: What am I looking for. Go for a pair that is more fitting for the stuff you listen to the most. If You only listen to classical orchestras and alike, I guess You should stop reading. You need to look for stax-phones. Very Expensive. Only worth having if you are a feinschmecker.
My playlist when trying out music is stuff like Deep Purple, Child in Time, Roger Waters Amused to Death, preferably the whole album. Nina Simone, Feeling good, Peggy Lee, Fever, Jazz, Blues. That kind.
That'll tell me wether there is bass at all, if there is decent mid-range, and also if the treble is non-offensive.
 
By reading a lot of reviews, these phones came out pretty good. Although! -The impression I was given by other reviews were that they were a little expensive compared to the sound given. This was when my critically inclined mental alarmbells went off. Things like being warm, 'muffled', having a 'veil' between the music and ear, making the music feel distant. I then recalled the good old days, where I built my own speakers, -the horror of screwing up the expensive hobby project, just to later have that Aha!- feeling of having to actually 'run in' the speakers before they are able to show off what they are good for.
 
Eventually, I decided for  these ones. I know Sennheiser from before, and I have never had/heard about any real issues about them before, Not being tempted by any fancy modern bling with buttons, sliders and glossy paper/plastic, I found a dusty box pushed in the back of the shelf.
 
The reviews were per se correct. warm, muffled, not very precise music. -So I bought them.
Day one. One big ''Meh. I exchanged the fake skin pads with the velour ones. Much more comfy.
and playing music, wearing them for six hours, before my ears got physically tired. I have a small head by the way. If you have a full size head, perhaps consider something else. They are a little tight, but I am trying to expand the headband(s) a little by the use of something wider than my head. This is probably the only minor con i have with the HD 25-1 II.
Day two. Sleeping well, doing other stuff, going back to my headphones, turn on the music. Same repertoire as yesterday. - There is a difference already. there is actually a soundstage there now, albeit small. they veil is disappearing and it doesn't sound that warm and muffled anymore. It is not neutral sound, but on the other hand, if I were to listen to a lot of classical, I wouldn't buy 'rock-speakers' anyways. I read reviews about how the phones were lacking in the upper levels, that sounds like -'S', -'SH', -'CH' etc would be... ...not perfect. Well, day two improved from day one in this aspect too.
The bass wasn't 'fluffy' anymore, but still deep. actually plenty deep, imo. and the midrange had improved a lot. from having to 'look' for it, to get it all the way to your ear without having to notice it was missing. Six hours, before they get uncomfy. -and after six hours, anyone will get tired in their heads/ears.
The headbands are not noticeable... ...and the cable is not in the way, nor noticeable.
Day three. Hah. Even better. After a total of 18 hours, the phones are now ready to be listened to.
You could say the virginity of it is now gone, and it is ready for some proper exercise and training.
I am not going to blast the volume on max for any reason, just so its said, but now i don't mind my equally critical friends to listen to them.
Day four. time to write a review.
I can only assume the sound in them will get better and better as time goes by.
The only, and ONLY thing that would make these better, were if the sound picture was wider and deeper.
It isn't a must, but it would be nice. After listening to High-end systems with SNELL speakers, more expensive than my pants can carry the cash, an open environment, -or the lack of it iin this case -will be burnt into your mind, and one will never be completely satisfied, unless buying super expensive stax with equally expensive amplifier(s), used on an equally expensive high end stereo setup.
 
These are lightweight, durable, good bass, good mid-range, good treble, even for sibilant music (Beware of Justin Bieber... ...the phones can't take that. The speakers will crack and fall into a hot,deep pit where beelzebub and his minions are removing impurities from the liquids in their forges.)
Seriously, the higher areas of music are just fine in these phones. -already by day three/four.
Every part can be exchanged.
If only the Amperior was cheaper, I'd go for that one. It is better, but kinda expensive if one doesn't have the money for it, you know what i say.
 
All in all. You can't go wrong with these ones. -unless you have extrordinaire music taste, are analythical instead of enjoying the music, like a nice glass of brewerage. I don't taste and spit the red wine. I drink it, and enjoy it for what its worth..

I never thought that there's such a headphone like this existing! Everything that I'm looking for for a headphone, I found it all on this hp. Cool looks (at least for me), changeable parts (especially the cables), superb clarity with excellent bass response, and lastly, known for its superb durability.  

 
The HD 25-1 is more than a great sounding headphone, it has stood the test of time, and proved to be one of the worlds most durable and versatile headphones. There's many detailed reviews of this classic headphone, so I won't go too much into the details. In short, all I can say is the hype and praise these headphones have received is well deserved. After owning these, I began noticing professional DJ's and Sports Announcers on TV wearing these all the time. Funny I never noticed that before, but I can see now that they use them for a good reason. I think the reason these are so well regarded is more so because of their design/comfort/durability/versatility vs their sound quality (which is great too).
 
Sound (9/10)
 
The sound signature of these is quite balanced, with a slightly above average bass response, likely due to the above average isolation they provide. The sound stage is about average for a closed headphone in this price range, but the separation on more complex compositions is impressive to me. They are very sensitive and easy to drive, which makes them ideal for portable use. They get loud enough to be dangerous, even from portables. Like most higher end headphones, they also benefit from high end amplification, but it's by no means required to reach their potential. Due to their balanced sound signature, these will please lovers of any genre of music. They are equally suited for gaming or movies also. Gave it 9/10 due to the average sound stage, there's other closed headphones that do better in this regard.
 
Design/Comfort (10/10)
 
The reason Sennheiser built a reputation off this model is the design and versatility of it, it is a true feat of engineering. The plastic is of high quality, making them light and durable. The clasping force is moderate, and combined with the Velour ear pads, I notice no discomfort at all when wearing them all day, even with my glasses on. With the leatherette ear pads they come with, you will get warm after 1-2hrs, but you get a slightly better seal, which improves bass impact slightly. I think the added comfort of Velour more than makes up for the unnoticeable decrease in bass impact. It's easy to get the right seal on all head sizes/shapes. Once there on, they stay there, even when running/exercising. The split headband helps keep them from moving. 
 
They look good when there on, not overly stylish or big, a more minimalistic look. The cable is just the right length too (1.5m), and conveniently terminated to a 90 degree 3.5mm connector, with a screw on ¼ inch adapter too. For those who care, mine say Made In Ireland. Because these are so modular, you can easily take these apart and customize them with custom paint jobs or after market cables if that's your thing. All the parts are easily replaceable, and easily available, which is something no other headphone achieves in this price range with this sound quality and comfort/durability. For many, this headphone is the last one they ever purchase, simply because it won't break, sounds great, and is so versatile. For those who manage to break something, a replacement is easy to find. That's why you see so many professionals using these on a daily basis.
 
Verdict (9/10)
 
I highly recommend this headphone, for anyone. It will be the last headphone you buy. I can honestly say I was skeptical of the hype these had, but after owning them, I quit using all my other closed headphones in favor of this one, not just for the sound quality, but the versatility it provides. It's like a good ol' Acura; it might not look the most flashy, or perform spectacularly well in any one area, but it does everything well, takes a beating, and never lets you down. Gave it 9/10 due to the constantly raising price of this model.

Good sound quality and good comfort. It is fairly lightweight but durable. The stock cable has some horrable mechanical transported contact noise (Some call it microphonics but microphonics is where mechanical vibration is transformed into electrical signal) so i replaced it with the HD650 stock cable. Yes i had to reverse the cups to make it fit.
I use it with a rockboxed iPod video and the RSA Hornet. Listening with crossfeed on i can listen to this combo for hours.
I listen mainly classical music. Opera, orchestral works, string quartets etc.
In my opinion, a closed can does not need to be perfect. i use a closed can to be isolated from outside noises but no passive closed headphone can isolate me for 100% so i will hear always hear some distracting noises
 
a great allrounder.
I do not really need a neutral sounding headphone since what is neutral nowadays? only my own ears listening to a live concert.
and my ears are not yours