Hello everyone. I'm going to review Sennheiser's HD598 audiophile headphones, and give you an overview of my personal opinions on it. These seem to be one of Sennheiser's most esteemed set of cans, so if you really want to know what all the jazz is about, well here you go. Feel free to agree or disagree however you find suitable, however I warn you, if you disagree with me, you are provoking the wrath of the almighty audio gods, so I would be wary if I were you.
 
I got these headphones about two months ago and have been giving them lots of good critical listenings through a variety of different situations. Overall, my impression of them is extremely favorable and going back and forth between these and different sets, I always seem to crawl back to these. I'm just going to break down each aspect of these step by step just for you. That's right. I love all of you... well, not really.
 
Source: Droid Razr Maxx @ 320Kbit/sec MP3. 10 channel EQ'd to my personal preference. 
Amp: FiiO E09K
 
20 hours of burn-in (if there even is such a thing)
 
Accessories
The HD598s don't really come with much, and this might be a little disappointing to some people. The only accessory that it comes with is a 1/4 inch (6.3mm) female to a 1/8 inch (3.5mm) male adapter. It's my opinion that Sennheiser should have at least given some sort of complimentary box, given that you shell out a little over $200 for these (which some ignorant people might find to be excessive). But to no avail, nothing else is provided with them.
 
Cable
The cable is nice and sturdy. It is removable from the headphones, and only goes into one earpiece, which is nice since now you don't have to worry about jerking your headphones off of your head. However, the fact that it terminates in a 6.3mm plug is sure to cause a lot of frustration with some people. These headphones definitely do NOT need an amp to run proficiently, and the fact that if you want to plug them into your phone or iPod, the plug coupled with the adapter effectively becomes as big as a pencil. Now, while the fact that these cans were never meant to be mobile is quite obvious, it still is annoying that you can't really replace the proprietary cable with anything else. What would have been better is if they made the cable terminate in a 3.5mm plug, and if you want to plug them into an amp, just get an adapter for it. Really, a 3.5mm to 6.3mm adapter is not that big or intrusive at all. Minus one for intelligence.
 
Build
This is really where the 598s begin to hit the high note (no pun intended). The creamy, somewhat antique look to them is sure to please a lot of people, but it is also sure to repulse others. To me, I think it looks absolutely gorgeous. Everything on this is plastic, but don't fret yet (hey that rhymes!) because this is a very, very high quality plastic (I know it sounds cheesy). I don't really know what to compare it to, but I assure you that the plastic feels very good, and it doesn't feel cheap at all. The headband is cushioned with almost an inch of padding, and when you put these on, it's almost like you forget they're even there. Another plus is the ear pads. The brown velvet is extremely comfortable, and if you've ever had those really soft pajamas that you feel like you just want to cuddle up into, that is what it feels like. Very nice. Sometimes I will find myself just petting the ear pads like a dog because I feel this incessant need to give them love.
 
Let me reiterate, the overall weight is so little, that when you put these on, they almost literally disappear. They just become another part of your body.
 
Sound
Now for the good stuff.
 
This has been the centerpiece for a lot of controversy in the audiophile world. In no ways is the bass on these powerful, and it is most certainly not the main attention that these headphones give. That doesn't necessarily mean that they are bad, just a tad bit recessed compared to other headphones in the same price range. Sub bass is slightly underpowered, and mid to upper bass are both more present, but seemingly lacking just a tad bit (however this is totally subject to opinion). Now don't let this get you down, because you can still hear the beat of the drums, the pluck of the bass guitar, and everything else that the audio masters want you to hear, but don't expect to be wowed by them. To some people, this is actually a good thing and they feel like it provides a perfect tonal balance. Others feel that it could be given a bit of a boost. Opinion: Even though I am a little disappointed with the bass, that doesn't drive me away completely from them (for reasons later mentioned). Even with excessive equalizing, these still have trouble accurately representing bass-heavy tracks. For instance, take Another One Bites the Dust by Queen for example. If you don't know this song, get out right now. I want nothing to do with you. Anyway, I'm actually listening to this song right now, so here's what I'm hearing: While there is still a bit of punch that you can feel from the drums, the main bass line lacks impact. Yes, I can hear it perfectly, but it just seems to me like there's just something missing. My friend's tube amp actually corrects this problem, but unfortunately I don't have one of my own. If you try to play dubstep on these headphones, you might be better off trying to convince Nancy Pelosi that capitalism actually works better than communism. Just won't work.
 
Again, this is completely up for opinion as if you like this aspect of it or not, so if you're not sure, try to find someone that has the 598s and see for yourself.
 
Edit: After about 40 hours of burn-in, I have actually noticed that the bass has become more pronounced and punchy, however still a little recessed. Nonetheless, I actually like the bass better now as it seems to have more umph to it. Even though I stated before that I'm pretty critical of burn-in, I can't deny that either my ear or the headphones have changed to make the bass a whole lot better. Whatever it is, it is a lot better. However my rating still stands as I believe it can still be just a little bit more punchy. But it still is very nice now!
 
If I could sum up the characteristic of the mids on this set, it would be "tasty". Yes, tasty. Hold on a second, let me switch the song. Okay, now I'm listening to Still Got the Blues by Gary Moore. The guitar solo that Mr. Moore shreds out around 3:45 is EXTREMELY well presented by these headphones. When he switches down to the bridge pickups on his guitar, it literally makes my spine tingle with how well the mids on these things do. It is just so intensely crunchy and powerful. Almost makes me want to cry. Besides that part, vocals are very very easy to hear above the instruments. It does not strain you at all to understand what the singer is saying. If you care to look at my review I did on the Sony XB-1000s here on this website, you will find that they did an absolutely horrid job of presenting vocals. That's to major contrast with the HD598s. It's just absolutely fantastic. I don't really know what else to say about it because it's just so freaking perfect. Smooth as silk.
 
A lot of problems that headphones have is with sibilance. Sibilance is that cringe-inducing sound produced by the crash of a symbol or by the iteration of the "ssssssss" sound. With the 598s, I can say with utmost confidence that sibilance is completely non-existent. The symbols on drums are heard very clearly, yet they don't make you cringe at all. Squeals on the guitar make your spine tingle. Everything about the highs is buttery smooth and not fatiguing in the slightest. When playing games such as Battlefield 3 (CoD sucks by the way), gun shots are head rattling and whenever a sniper bullet whizzes past your head, it makes your heart jump. It's intensely powerful yet staying reserved enough that it doesn't rustle your jimmies. It's like these are balanced just oh-so perfectly, and really I wouldn't like the mids or highs to be any other way.
 
***Note about burn-in***
The only time I've really noticed any change in the sound signature in these headphones is around 3-4 hours. After that, I haven't noticed any other changes. However, I am extremely critical of burn-in, so I'm assuming that it may just be my ear getting accustomed to the headphones.
 
WOW!!! That's all I've got to say about that! Instruments are spaced out extraordinarily well, and sometimes you are left wondering if what you are hearing is coming from your headphones or the world around you. Like other reviews have done well to describe, it's like you are in the actual studio (or stage) where the band is playing. This is especially good for gaming because it allows you to hear precisely where other players are. I can't tell you how many times I've been able to get the upper hand simply because I could hear someone coming my way before I could even see them. I can't impress upon you enough how well the spacial distancing is on these cans. I can literally tell exactly where someone is coming from and about how far away they are solely due to the fact that the soundstage is so amazing. This characteristic can be mainly attributed to the open-back design of the speakers. Note that this actually might be a problem for some people because they block virtually no sound. People around you can also hear everything that you are listening to as broad as daylight.
 
These are also some of the most clear headphones I've ever heard. Every beat, every pluck of the pick, every breath of the singer can all be heard with the minutest of detail. I was also shocked to realize that in certain songs, I could actually hear the metronome in the background, which is something that most headphones would fail to present. Beats fanboys would say "hurr durr why would you want to hear a metronome." Well, that's not the point. The point is that the headphones produce such great clarity that it just so happens that you can hear the metronome. My goal in life is not to purchase headphones that play the metronome. It's just BECAUSE they are so clear, that you can hear it.
 
It is just absolutely astounding the resolution and clarity that these provide. Now don't get me wrong, I agree 100% that there are clearer phones out there, but for the price range, there is almost nothing that beats it.
 
Overall Impression
The wow factor on these headphones is truly something to behold. While the bass to some might lack impact and force, the mids and highs make up for it by presenting a crunchy and very satisfying tone. The cable is a little annoying and I wish that Sennheiser would have included a 3.5mm terminated plug since these headphones most certainly do not need an amp to be driven sufficiently, but I can see the reasoning behind it. These were never meant to be taken out of the house. Sound leakage is a problem, but that is certainly to be expected with all open-back headphones. If you are looking for an excellent entrance into the higher-quality headphone community, this has got to be on your list of consideration. It really is a great set.
 
Price range rating: 9/10
Would give 10/10 if Sennheiser would include a 3.5mm terminated cable and if the bass had a little bit more impact.

This is just a short review for the monstrous XB1000 if anybody wants some opinions on it. I realize I'm a little late to the party, but hopefully this thread can go onto Google caches so future people can make an informed decision.
 
 
I received the headphones about a month ago and have had enough time to thoroughly gain a (somewhat) accurate opinion on these. Previously, I had owned the MDR-XB700s which are the 1000's not so little cousins, and being quite satisfied with them, I decided I might as well go ahead and step up the game with the huge 70mm drivers that the 1000's are famous for. Well let me tell you this much, when you receive them in the mail, pictures really cannot do you justice to explain how tremendously huge they are. They are bigger than the width of my palm, and the dictator-sized cushions that Sony lavishes you with are initially extremely comfortable, and are sure to give you lots of strange looks, should you go around town with them (which you probably shouldn't in the first place).
 
Amp: Fiio E09K desktop amplifier
Source: Android HTC Rezound (with radio turned off to prevent RF interference) @ 320 KBPS MP3. I know I know, get over the fact that I don't have a DAC people.
 
20 hours of pure white noise applied
 
Build: These headphones are built very sturdy and have an almost complete metal construction, unlike the 700s which consist of a plastic backing to the actual speakers, while still maintaining a metal band. The complete black look with this odd cube(ish) design on the 1000s is very visually impressive, and it gives them a very urban feel. I haven't really felt like any part of the phones was designed poorly, in such that something might break. They feel very robust and sturdy, which is something I think is a big plus for these.
 
Comfort: While the huge pillows that rest on the side of your face was initially a very good idea, I think Sony might have really done too much with this one. While they are very comfy for a while, the sheer weight of these monsters start to become extremely noticeable when you wear them for any length of time. The headband has very little padding at all, which is slightly disappointing. I've played games with them before, and after about 2 hours of wear, it becomes almost a burden to see these things in your peripheral vision all of the time. If you try to sleep with them on, forget it. You can't turn your head anywhere except for a straight on 90 degree position (to your actual pillow).
 
Sound: This is really what you all have come here for, isn't it? Well this is a little bit complicated to explain, and it's probably best to just break it down step by step in accordance to the appropriate frequency ranges as most reviews seem to do.
 
 
The lows on this thing are some of the deepest and most lush sound lows I have ever experienced. It can almost be compared to having two huge subwoofers placed directly next to your head. That is how crazy it is. I looked up a bass test on YouTube and did one of those, and holy mother of God, it is so extreme that these headphones were successful in *literally* shaking my head. The drivers on these things are so ridiculously huge that they were almost jumping off my head. It could handle deep sweeps very well (and with ease, might I add), and seemed to handle rough tracks to play very well. It really is just to leave it at this: just think of a really good set of subwoofers in someone's car. That's what these are like. I think that this is the most refined bass in the entire XB series, and it is most certainly noticeable once you first try these out. It manages to be very tight, and is very good with any song that has lots of bass.
 
 
This is where we begin to lose it a little bit. I'm not the best at explaining mids, so just bear with me. Since such a disproportionately huge amount of emphasis is placed on the bass, I think the mids are kind of lost in the shuffle and seems like they are almost forgotten about. Voices are sometimes extremely hard to hear, even with the best equalizing, and really aren't that good at describing a tracks more "feel-good" tones. While it is still possible to equalize a song so that you can hear more of your favorite ranges in the mids, it always seems kind of off and not exactly right. For example, when a guitar player is shredding out a really sick solo (think Still Got the Blues by Gary Moore), you can't really feel that crunchy, spine-tingling resonance that Gibson Les Pauls are trademarked for making. It's like you're always thinking about the bass on these headphones, because it's always present and noticeable. Not good.
 
 
This is where I have by biggest gripes. I think that the highs are almost completely washed out by all of the other frequencies. Sibilance (the sound produced by pronouncing an "s;" live around the 2-4K range) is a huge problem with these. No amount of vain contesting with the EQ is able to get rid of this problem and it leaves you always cringing whenever the singer sings just the wrong words, or the drummer hits just the wrong symbol. This is something I've noticed almost directly out of the gate, and is probably one of the single most outstanding acoustic design flaws with this set. If highs are what you crave, you might as well be better off buying some Bose QC 3's *gasp*.
 
Overall impression: I don't know if it was intentionally designed this way or what, but it seems as if this set is produced solely for dubstep, house, rap etc (the stuff with bass). In no way, shape or form are these good for anything like classical, rock, country, pop, Lady Gaga (I consider her to be a completely separate *terrible* genre), or anything of the like. If dubstep or rap is all you listen to, these headphones are great! However, anything else and you will be left in want. Just a word of advice, it is imperative that you use an amp with these because even though they have a relatively low impedance, the 70mm drivers command lots of energy flow to be able to move all of that air.
 
So, what did I eventually do with these? Sold them.
 
I hope you all have an excellent morning, noon, afternoon, day, night, midnight, or double sun set if you so happen to live on Tatooine.