Pros: incredible mid-bass, detail, build quality, isolation, soundstage, comfort, engaging
Cons: sibilance, too bright sometimes, unforgiving of low quality recordings, the holographic soundstage, comfort (a little clamping for some heads)
One of the best headphones for gaming and movies - superb for EDM and dubstep
Source 1: Asus Xonar Essence ST (OPA2170 + JRC2114)
Source 2: Audio-gd NFB-3.32
Cables: Signal Cable Analog II and stock coiled Neutrik 3,6mm
Amplifier 1: Matrix M-Stage (with LM4562)
Amplifier 2: Violectric V200
Skrillex, Knife Party, Netsky, Adventure Club, M83, Infected Mushroom
Florence and the Machine
Foster the People
(All the tracks were FLAC/ALAC 16bit 44.1kHz and 48kHz with ~1000kbps)
The Ultrasone PRO 900 have very robust / sturdy and have a beautiful silvery/metal-like finish to it on the sides of the phones. The general build quality seems very solid and it wouldn't amaze me if this thing could take a lot of beating and survive. They're also a bit heavier than your average headphones, depending on your model of course. Other closed headphones could be a bit heavy, but open cans are generally very light in comparison to these. They're also designed to be portable, probably a really good thing for DJing? You can fold the phones up to the rim and if you have deep pockets they can fit in there, otherwise you have a neat little bag that's included. Changing earpads is also easy peasy, you just rotate/screw them gently to either side and they come right off. Putting new earpads on is just as simple, just press them in where they fit with the bent edges (just like placing a square or a star into one of those boxes for babies) and then rotate them on so they lock.
At first wear they feel odd on the head. Since the headband is fairly bendable there's not necessarily much clamping force, but there's a tad more force on the upper areas of the earpads just above the ears. But after a while this is overlooked and the headphones are pretty comfortable, not really that clamping, and the earpads are softer and a bit more comfortable than the ones on the HD650, but still doesn't beat the comfort of the DT990. Overall I would say they're comfortable, more than could be expected. But I should add I have a fairly small head - and I could probably see and issue with people who had bigger heads. Earsize could make an impact as well, but unless you have troll-like massive ears I wouldn't be worried. They're about the size of the DT990. Some people have complained about the padding on the rim which feels uncomfortable on their heads. I can feel it sometimes too, but I won't attribute it to the padding but rather the weight of the headphones - they are fairly heavy, noticably heavier than my HD650 and DT990. Atm I feel quite comfortable with them on. They're not clamping and I don't sweat with them on. However, sometimes the weight can be a little straining and fatiguing; that is my only dislike about the comfort of the PRO900.
Initial impression (Burn-in 1-2h)
The first hour of burn-in the Ultrasones PRO900 was hideous. I tried it first straight through the HP out on my Xonar Essence ST. As soon as I connected my Little Dot MKIII it became much more bearable. The warm tube amp managed to soften the higher end of the headphones and brought extra thump and depth to the bass, but still, the highs were prominent and on some tracks I felt a terrible sibilance that could not go left unnoticed. At this stage I realized that I will need many more hours of burn-in. At this stage I also played a random trailer in HD called 'Sorcerer and the White Snake'. I'm a huge film buff, but this trailer seemed like a total piece of laughable garbage. But nontheless I was captivated by the sound the PRO900 managed to present that I disregarded the cheesy CGI effects of the movie. The bass was brilliant: deep and detailed, the highs in this case worked well in the trailer and I can see the V-shape working quite good in movies and possibly even games. The soundstage also felt deep, but not necessarily very wide. I wouldn't call it bad, it's good. But going from the DT990s I felt something odd, I think it could be because of 2 things: the intruding bass, and the fact that the headphones are closed designed - but nontheless there was a good soundstage despite it not being very airy/open (I suspect it is the S-Logic in the works). I also took the liberty to listen to a few dubstep tracks. Generally I don't listen to this genre much, but I thought I'd bring some of it in when reviewing the PRO900 since they should excel in this type of electronic music. I have to admit they have much more power and thumping bass when comparing to the DT990s. Some tracks however were very heavy on the highs, there was still noticable thumping in the background, but you could definately feel the texture on these tracks, which you could not on the HD650 for example (the bass wasn't even present on the Sennheiser). Skrillex - Alejandro is not that bass heavy track, but there's a beat in it that I dig, and it was really present and deep on the PRO900, I remember how I kept tapping my foot to just this track, and even though it was just the first hour of burn in and the highs felt at times pretty sibilant, the PRO900 were very enjoyable with this genre. The DT990s were also bright, but softer and with less bass, at least not as deep and punchy as that of the PRO900. I felt the soundstage was more enjoyable on the Beyers.
~24h Burn-in: The bass has become more pronounced and emphasized. The highs are slightly, just slightly more defined but still quite sibilant at times. It's less dry, but only by a margin. I believe I will have to wait longer for the final burn-in process to finish. I'm estimating around 100+ hours judging by the other members.
Burn-in after 24h
The bass seems to gradually come forth more, and apart from minor detail adjustments I felt more impact from the beats. The highs were a little smoother, but just a little. I can imagine I would need a lot more time to burn these in, I'm expecting around 300 hours considering what other people have said.
Conclusion: If possible, I would recommend a warm amplifier - but since it's a low impedance headphone you would mostly be restricted to solid state amplifiers, unless you have the money to go for a tube amplifier with an output transformer - or possible a hybrid amp like LD1+ if you find it good sounding. Having a warm source might help also, but only marginally - however I can imagine either the Yulong D18 or Rega DAC having some impact with their rather analogue sound (I have not tried these DACs so my I'm only speculating).
My gear consisted of rather budget-oriented equipment but in good stuff for the buck. I can imagine the Ultrasones sounding even better on more expensive gear. I recommend these headphones for some electronic music (mostly dubstep). But overall I would classify these headphones as great for movies and games, it brings a new dimension to these medias' sound and make them more immersive than is. A little convenience of these cans is that they're portable: either by using the small neat bag, or by just folding them in - just expect to bring them to a place where the equipment is made to drive them properly. But, portability might not always be a convenience with these cans. Maybe if you wish to take them with to a meet or to a friend's. People have reported that the PRO900 work well with the portable Fiio amps. Just because they have low impedance does not make it easy to drive in my opinion. You have to take into consideration 1) output impedance and high damping factor for better bass response and 2) output power. The M-Stage runs at 5ohm output impedance (which is ideal for 40ohm) and 400mw/60ohm. It does quite well for the PRO900 and its slightly warmer signature is a good compliment to the brightness of the Ultrasones. However I can imagine these headphones pair very well with the Violectric V200.
Impression after 300h
I let the headphones play for more than two weeks through the M-Stage and normal to high listening volume (listening only 15 minutes each 2-3h interval). I can attest to the marginal difference in sound (without trying to be affected by brain burn-in). The bass feels fuller and it seems as if the low-end has gotten more body than it used to have. The sibilance however is still a big factor in this - making some tracks less listenable to, but it's not as terrible as it used to be. The op-amp change in M-Stage could factor in on this.
There is definately a discernable holographic soundstage on these headphones despite them being closed. They aren't as airy as the HD650 or DT990, but they do have a sense of width and depth, still. Some people may call it 'fake' or 'unnatural' and to a certain extent I would agree. The best I can compare this type of soundstage, most likely a bi-product of the S-Logic, is to Dolby Headphone. What it does is that it creates an audible space between the ears and the instruments, making it feel as if the sound is further away from where the drivers actually sit. If you know what Dolby Headphone with Virtual Surround sounds like then you can expect a similar effect from the PRO900. Though its effect is probably just half of what Dolby Headphone produces, which is good news for you who don't like DH. I find this ideal for HD movies and gaming, especially if you have Dolby Headphone enable when using the Ultrasones.
This is an important factor to closed headphones, mostly because you don't want any sound leakage for others to hear, but also to help prevent you from being disturbed from outside noise - it also contributes to the bass response, as you may be aware of. When I wear them I barely hear much from my surroundings: I have a mechanical keyboard which can make much noise sometimes, especially when I play games or chat. Playing music while typing is no issue, but I can still hear the keyboard if I stop the music. Also, when people speak I usually have to take off my headphones to hear them clearly. From a 3rd person perspective there was minimal leakage on medium to semi-high volume on bass-heavy tracks.
This is probably what makes the greatest representation of the PRO900's signature. It's quite deep, very punchy and detailed+controlled. I would say it excels more at mid-bass rather than low-bass. I haven't tried any headphones that do low-bass very well, but I believe the Sony XB-1000 or the XB-700 and the Denons should fit this bill. The bass on these headphones can probably be described best as a built in subwoofer. When the bass hits as deepest (especially with some EQ) on some tracks or movies it literally feels as if the ground is vibrating; as if you have a subwoofer standing on the floor. It's a very interesting sensation, although it's all in your head.
On music the mid-bass shone. It gave so much texture and quality + quantity to dubstep that I could listen to the genre for hours even though it's not really something I prefer listening to. The impatcful and quick punches worked really well with the treble on most electronic songs (but mostly just dubstep, it don't work so well with most Röyksopp tracks). The sub-bass was also quite good. For example, 'Knife Party - Sleaze ft. Mistajam' was head-shaking and punchy on the PRO900. However, do enjoy this type of mid-bass at its fullest the tracks got to be emphasizing this frequency, I found most of the tracks from Knife Party and Infected Mushrom do this well.
Another part of the signature, contributing to the V-curve in its frequency chart. Think of it like this: the highs are just as prominent and exaggerated as the bass on these cans. Whether it's a good thing or a bad thing is up to you. Personally I think it's more straight forward and engaging, but it's gone way further than the DT990 - even to the point where you could hear sibilance depending on what song you listen to. Burn-in helps soften the initial peak, but it won't go much further down. Luckily, it does go down after burn-in, unlike the bass which seems to go up after burn-in. Listening to Fleetwood Mac was not a very nice feeling. It was overly bright most of the time, and when the cymbals struck it was really high and screechy. To sum it up, on dubstep and most electronic music I ended up raising the volume for more bass thumping; but on pop and folksong I had to lower the volume due to its excessive amount of sibilance. Röyksopp was a mixed bag. I absolutely loved how the Ultrasones performed on 'The Girl and the Robot' for example, but on other tracks the highs were too umbearable. Same goes for 'Florence and the Machine - All This and Heaven Too' where sibilance was very noticable on the many 'sss'es ontop of it being a female vocalist. Same goes for the cymbals and drumkicks in 'Foster the People - Waste'. Short answer: depending on the source it can become very fatiguing at times, and rather than tapping your foot to the rythm you oftentimes end up taking the headphones off for a break. 'Susumu Hirasawa - Yume no Shima Shinen Kouen' however was by far the worst track for these cans. It was so bad that I felt like pressing two screwdrivers into my ears just to remedy the damage done to my head. These headphones need very specific music! You have neutral cans, you have allrounders, and you have basshead cans, THEN you have the Ultrasones.
The Sibilance and its Sensitivity
This is the inconvenience of these headphones. Due to its bump in the higher frequencies the sound can be very sibilant depending on the recording. Florence and the Machine did absolutely not work on the PRO900. Florence has such a bright and loud voice which I love, but on the PRO900 it is something that I hate. The PRO900 is also quite unforgiving of low quality recordings and quickly points out the flaws of your tracks. This could be attributed partly to sibilance but also its sensitivity. I still have some 128kbps to 256kbps songs and the Ultrasone did pronounce how low of quality they are, and it can be very unforgiving. Through the V200, which is generally very silent, the PRO900 made a little noise audible at max volume without extra gain setting. And while listening to some orchestral tracks in FLAC/800kpbs, I noticed some background noise of the instruments and recording room which I had never heard before. May this be a good or bad thing, in any case I wouldn't recommend them with classical and orchestral tracks.
Not a strong point of the PRO900 as the mids are very recessed, even more so than on the DT990. And consequently it makes some genres of music quite unbearable to listen to, especially Susumu Hirasawa, Fleetwood Mac, Florence and the Machine or Depeche Mode; that is when my HD650 shines. In comparison PRO900 sound hollow.
I think an amplifier in general is important overall for hi-fi headphones, but more so for Ultrasone PRO900. I tried three different amps in this case, gradually stepping one in the price range and quality and sound signature. The first contender was the built-in headphone amplifier in Asus Xonar Essence ST which runs at around 11ohm output impedance and can drive headphones up to 600ohm - it did a good job driving my DT990. But how does it go up with PRO900? So-so. The most think that I found was lacking was the bass, the treble was too overwhelming. Of course I could counter this somewhat with some equilizing - but without damping factor in motion I could hardly get to the PRO900s true signature - and the treble still peaked the bass on bass-heavy tracks. As soon as I switched to the Matrix M-Stage everything seemed so much better! The ouput impedance is at 5ohm on the M-Stage which is a perfect suit for the 40ohm on the Ultrasones - plus the LM4562 op-amp added a warm coloration over the stock op-amp that went really great with countering the treble-peak of the Ultrasones; it also added a thin extra layer of bass quantity. And this time I felt that the bass was more emphasized than the highs but not only that... they felt fuller now and powerful and not as thin and metallic as they did through the sound card. In my opinion the M-Stage is a perfect match for these cans at this price range. Now, can the Ultrasone PRO900 get any better? These are things that I've heard, but since I no longer own the Burson HA-160 I could not try it out. Although, I have tried it on the V200 and found that its grainy treble was 'tamed' by the smoothness of the Violectric. However, the treble will always be there (maybe less sibilant on greater/coloured amplifiers), but not so much if you compare its use on cheaper amps. I don't honestly think it's a true musical or detailed/analytical audiophile headphone, but it's still very fun (maybe hateful and unforgiving sometimes) and very engaging. Other amplifiers I do believe work well with the PRO900 are Burson HA-160 and Yulong Sabre A18 since they share similar character as the V200, but maybe even more so, at least the Burson HA-160.
In other areas
Brilliant headphones for FPS gaming, I'd say. Battlefield 3, Counter Strike, Metro2033, Skyrim felt much more immersive and engaging. Especially with its S-Logic holographic soundstage and deep lively bass. Explosions never felt more powerful and real when shooting from a tank or having a grenade explode some yards away from you. And the shouts never felt as overwhelming and authoritive in Skyrim as with the PRO900 (especially in the intro theme: you can literally feel the choir reverberate in your head). And in this case I really think the V-curve sound of these headphones work really well! It might just be my personal preference but I would generally prefer games to emphasize the highs first and low-end to mid bass. Bass would attribute to the more immersive sound of explosions and gunshots for example, while the highs apply to voices and detail to footsteps etc. I have used my HD650 when gaming as well and felt them less engaging and alive than my PRO900 simply because of its emphasize on midrage and weaker bass. Of course they feel slightly more airy/spacious as they are of open design, but other than that I don't feel the same vibe in games I get with the PRO900. The only issue I had with these cans in gaming were possibly in games like Crysis. Because of the extreme highs the voices over the radio were very shrill and annoying. I also mentioned that explosions and shouts seemed very powerful - to a degree it is true, but the gunshots were more prominent as these cans emphasize mid-bass. For more rumble I'd suggest a pair of cans that has deeper bass extension and does low-bass really well. The PRO900 does it well in fact, but its strength lies in mid-bass.
Ultrasones went really well with movies, especially with the action genre (and its many sub-genres) as it presented a very lively and powerful bass and this semi-artificial soundstage. It sometimes felt as if I was sitting in a room with speakers and a powerful subwoofer pumping on the floor. Similar sensation can be achieved with Dolby Headphone, but I found the Ultrasones working just fine without any DSP. I should also add that when comparing the Ultrasones PRO 900 to the DT990 600ohm in movies (where I would say the DT990 won in terms on soundstage), there was an interesting finding that I made in one scene of the film 'Tower Heist'. It's an indoors scene and you can hear a car drive by outside rather faintly. On the DT990 there was nothing unusual, sounded just as a car should. But on the PRO900, on the other hand, it sounded rather unnatural and impactful; imagine watching 'Transformers' or something with exaggerated electronic/robotic sound with a plentiful amount of raised bass - that's what it sounded like, as if the car's movement affected the door/walls of the building making them 'vibrate'. I kind of like this effect when watching films, but might not be suited for those who want a more natural film watching experience. Of course, I would resort to my HD650 when watching more serious films; the PRO900 will be reserved for shows or commercial (mostly action-packed) movies. The film genre must be very specific when choosing to use the PRO900 respectively the HD650.
If possible, I would recommend a warm amplifier - but since it's a low impedance headphone you would mostly be restricted to solid state amplifiers, unless you have the money to go for a tube amplifier with an output transformer - or possible a hybrid amp like LD1+ if you find it good sounding. Having a warm source might help also, but only marginally - however I can imagine either the Yulong D18 or Rega DAC having some impact with their rather analogue sound (I have not tried these DACs so my I'm only speculating). The V200 is quite warm sounding, but with detailed highs, perhaps not as emphasized with rolled off highs as perhaps a Burson HA-160, but a good pairing with the PRO900. It smoothes the excessive treble peak and refines the sound even more - especially in the bass department as it bolsters a great bass extension.
I can recommend these headphones for some electronic music (mostly dubstep). But overall I would classify these headphones as great for movies and games, it brings a new dimension to these medias' sound and make them more immersive than is. A little convenience of these cans is that they're portable: either by using the small neat bag, or by just folding them in - just expect to bring them to a place where the equipment is made to drive them properly. But, portability might not always be a convenience with these cans. Maybe if you wish to take them with to a meet or to a friend's. People have reported that the PRO900 work well with the portable Fiio amps. They're not hard to drive, but I can imagine you'd want a considerably altered sound in your amp when using these ultra-bright, ultra-bassy headphones. I switch between both my HD650 and PRO900 from time to time but generally it looks like this, usagewise: Music + Films (less intense and more acting, scenic) for my HD650, and Games + Films (intense, action-packed) for my PRO900 (with perhaps the exception for EDM and dubstep when listening to Music). These two headphones are so dynamic in that they have so many differences in both strengths and weaknesses that sometimes I would recommend people to own at least 2 pairs of headphones - instead of focusing on just one pair as allrounders for all your sound oriented activity. Even if music is your primary (or only) activity then one type of headphone could perhaps not be enough unless we're speaking expensive orthodynamics and you're on a tight budget already. Think of whatever activity you value the most, or what music genre you listen to the most. If you listen to a lot of EDM, Dubstep, etc. then the Ultrasone PRO 900 is one of the best headphones for this kind of listening - they offer that umph that headphones like HD650 lack (or open headphones in general) and yes even the DT990s. Don't get me wrong, I loved the DT990s, but the electronic music I felt they worked well with felt quite restricting, tracks that the PRO900 nailed it in felt less intense and engaging on the DT990.