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Ultrasone PRO 900


Pros: Great bass and treble

Cons: Slightly recessed midrange, sounds can "bleed" a little, especially at high volumes

I've had these for a couple of years now (although they don't get as much playing time anymore) so I figured I'd write a review.  Of all of the headphones I have owned these are the ones that wowed me the most upon my first listen.  The bass on these is just ridiculous.  They are easily driven by an iPod/Phone but do sound a good bit better when paired with a nice amp.  Like many others have said these do best with electronic music, or anything aggressive, however I have found that they perform more than adequately with all genres of music.  They are a very clean and sharp sounding headphone.  My main complaint about these would be comfort, they clamp very tightly and it can get uncomfortable after a while.


Pros: Capable to deliver awesome bass / Comfortable / Detachable cable / Straigt and coiled cable / Two pairs of velour pads / Slick look

Cons: Way too strong on the lows out of the box / Perhaps not so good for music with vocals


This cans are able to deliver outstanding lows, but to sound good they need some EQ tweaking imo... I ended up lowering the region between 50 and 150 Hz and slightly raising the region around 2 and 10 kHz. I mainly use em for electronic music, that's where they shine and probably beat most other headphones out there. For other stuff like Rock, Metal or Classic I didn't enjoyed em that much, the mid/low region feels "anomalous" here, hard to describe.



I find em very comfy, just like my Beyers, velour pads FTW!



If they were 100 bucks cheaper I'd give em 4 1/2 stars and recommend em to anyone who likes Electro/Dubstep/Drum&Base etc. But for what they cost I only recommend to get em if other "basshead" cans (like the HFi580 or DT770Pro80) are not enough for you ;)


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

Music played:
Skrillex, Knife Party, Netsky, Adventure Club, M83, Infected Mushroom
Florence and the Machine
Foster the People
Depeche Mode
(All the tracks were FLAC/ALAC 16bit 44.1kHz and 48kHz with ~1000kbps)

The Design
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.


The Comfort

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.


The Soundstage

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.



Pros: Deep impactful bass, great soundstage, extremely detailed highs and mids, comfortable, look great, detachable cable, efficient

Cons: Recessed mids, not the most portable, leak quite a bit of sound, highs can get a bit extreme at times, HIGHLY recommend an amp (Fiio E11)

These are some excellent bass-head headphones. The sound is extremely clear, with an extremely tight, deep, well-textured and impactful bass, a clear midrange, and a very detailed high end. The mids are recessed, so if you don't like a V shaped frequency curve, then steer clear from the PRO 900. The highs can get a bit extreme at times, but I wouldn't call it harsh or piercing... I actually find it quite enjoyable. As well, the soundstage is excellent for a closed headphone, and the lows, mids and highs are all seperated very well. The PRO 900 are also very comfortable imo, and can wear these for hours, because of the soft velour padding. They look great, with the all black matte finish and the aluminium ear cups. Even though these headphones are efficient, I HIGHLY recommend an amp, such as an FiiO E11, which will drive them more than fine. Also, the PRO 900 are not the most portable, as they are pretty darn big. Overall, excellent headphones which I wholeheartedly recommend.


Pros: - great build quality - good accessories - good comfort [for some] - easy amping - rap/hip-hop/electronica master - great bass - awesome for gaming

Cons: - overly expensive - inconsistent - harsh treble - shrill highs - recessed midrange - discomfort [for some] - unforgiving - instrument separation

NOTE: This review no longer represents my view of this headphone. If you wanna read the updated review, visit my ultimate write-up page [in the sig]





Hi guys, to celebrate my 100 posts, I have decided to write my very first review.


The Ultrasone Pro 900 are my very first "audiophile" headphones and as such taught me many things about headphones.


They also helped me understand my music preferences, even changed them slightly.


I now know what I want from my next set of cans (the HE-500 or HE-5LE) and even after my currently mixed impressions, I would probably buy them again, probably...


More on that throughout the review.


Onto the review then :)


NOTE /I own these headphones 4 months already. These headphones should be fully burned in, so the sound signature is likely definitive/





The headphone comes in a sturdy case. The contents are the headphones with velour pads on, a 1/4 gold platted plug 5 ft long (5 ft + the coiled part) Neutrik coiled cable screwing directly into the Pro 900, a 1/8 jack cable 5 ft long (also screwable), an extra pair of velour pads, manual and CD.


Both cables are fully and easily detachable


The stock cables are of good quality. Not as fancy as some of the aftermarket ones, but very durable.

To screw in the cable, you simply push it into the connector and twist it clockwise. Keep twisting and the cable will screw itself in.


The velours are quite comfortable and fit nicely, but I will get to that later.

The mechanism is similar to that of the cable. Push in and turn clockwise.


The CD contains some test songs. The manual is very brief and is mostly a showcase of all the Ultrasone products.




Case closed




The headphones as they come in the box




The case, extra velours, manual, both cables as well as the headphones (stand not included!)


Score 8/10





These headphones excel in this category. They are build like a tank, with very durable plastics. There is not a single metal part, which may make these feel a little cheap.

The only aluminium parts are on the cups. It is the signature logo as well as the 'Ultrasone' sign.

This is also the only part prone to scratching. It somehow got scratched when I carried them around in my backpack. It is only cosmetic though }It is the right cup, visible on one of the photos I posted]


Score 9/10





Very unique looking headphones. I kind of like the design, but they look ridiculous when I wear them. They may not look it, but the caps are really big.

They are really one of the most original headphones as far as design goes. I, for one, enjoy owning things that are radically different from the usual 'casual' ones, so this is a plus for me.


Score 8/10





With these cans, this is a hit or miss. My ears aren't particularly small but ain't huge either. But after a few hours [sometimes even minutes] my ears start to ache.

I was not able to pinpoint the source exactly, perhaps the cups are too small for my ears or maybe my ears are rubbing the drivers, or both.

So for me they are comfortable only for a given period or time, sometimes longer, sometimes shorter. 

Also, the headband padding as you can see is very narrow and increases the pressure on one part of your head.




The cups are really huge and can be comfy at times.


Score 5/10





These cost me 500 dollars new. Their retail price was 550 when released, Now to make this clear, At first, I believed they were worth their price.

Now, however, after I have spent some quality time with them, I have to say they were overpriced. Vastly for me, for others... well, I will explain later on.


Score 4.5/10



Let's move on to....





First off, I will rate how useful they are for individual purposes.





They work well when connected to a phone directly.

However, I'm inclined to recommend something like the Fiio E11, which has a slightly warm signature, which helps the 900 sound presentation ever so slightly.

The cables used are the stock 1/8 cable and an aftermarket NUforce interconnect 1/8 - 1/8 cable.

The Fiio has a bass boost and gain settings, as well as a protected volume knob to prevent it's accidental turning in your pocket for ex. 



The Pro 900/E11 combo




The device is very compact and small, yet very powerful and capable. Fully worth it's 60 bucks asking price.



Now, I don't mind their larger size. It can be bothersome for others, but because they play really well as a portable headphones, I can recommend these for such purposes.


Score 7.5/10



ISOLATION - They isolate very well, I was able to listen at loud volume levels, without disturbing people around me. They also isolate some ambient noise, just enough to be okay for portable use. They pass in this category.


Score 6.5/10





Now, would I recommend these for your home rig...

This is where things get a little more difficult.

Due to their size, one might think they will benefit from better amplification and improve greatly with a desktop amplifier.

The truth is it does, but just a little and it depends on what amplifier you are using


I use the Audio GD NFB-16 as my main amp. It is a very neutral amplifier, with good dynamics and very transparent



The problem is, you don't want a neutral amp for these, not at all

I found the Fiio to be a better match than the Audio GD because it is a little warmer.

Now, why is neutral amp bad for these...

I will get to that later as well.

As of now, I wouldn't recommend them as your main set of cans.





The setup




The generally recommended Foobar player in use



Now, I am not saying they won't appeal to some of you, I just don't think they were meant to be used as a home rig but rather as a portable rig.

Ultimately, I was not satisfied with their performance with the desktop amplifier.


Score 4/10





Now gaming, much like portable use, is a category where they perform well.

I use a DTS 7.1 converter as well as my PS3 as my gaming rig.

They are a very 'fun' set of cans. They have nice dimensionality for a closed set of cans.

With their deep bass and prominent highs, they make every game very enjoyable. Be it shooters, RPGs, racing games or sports games, they produce exciting sound throughout.

Deep explosions, nice accuracy... Its all there in your games. May be a bit too aggressive for some.



PS3 hook up




The way its all connected



Overall I enjoy these greatly with any and all videogames.

They may not be the last thing in pinpoint accuracy and soundstage, but due to their sound signature, they are hard to resist. In this particular category they exceeded my expectations.


Score 9/10


Now, I will rate the Pros in individual categories across their whole frequency response.

These will be bass/lows,midrange,highs,treble,soundstage,instrument separation,bad source sensitivity and last but not least consistency

NOTE - if you listen to rap, hip hop and electronica ONLY, you can add a +4/5 points in the 'MIDRANGE','HIGHS' and 'TREBLE' categories.





From the start, it was obvious this will be their strong side.

They reproduce bass very accurately. It is not one noted or distorted.

The bass is deep, strong, slightly boomy [makes the earcups resonate sometimes] and very satisfying. Makes you smile once you get addicted to it.

Sometimes it gets slightly bloated or muddy, but overall the bass presentation is almost perfect.

Any low note instruments are presented with authority and domination.

Do note, that this makes the Pro 900 a very bass heavy headphone. So if you are a bass-head, crawling for more bass AND don't want anything else, look no further.


Score 8.5/10





This is where this headphone falls extremely short.

The mids are extremely recessed. I would say the midrange is practically non-existent, making this headphone a prime example of V-curved cans.

To understand, the mids are overpowered by both the thumping bass as well as the aggressive highs, both bleeding heavily into them, leaving no place for the mids to reveal themselves.

Here and there, the rare moments when you can hear it, you may realize it is quite nicely detailed. But most of the times, the mids are simply absent from the sound spectrum.

Now, if you listen to rap and hip hop or electronica only, this shouldn't concern you. Such songs in general do not require pronounced midrange, as a matter of fact they do not require any at all.

But the moment you want to listen to other similar genres, such as pop or [alternative] rock, you will realize these headphones were not meant to be used with these.

They are electronica, hip hop and rap masters, but as far as other genres go, they leave much to be desired.


Score 2.5/10





Aggressive, fatiguing, piercing, shrill, peaky, prominent, merciless, unforgiving.

These things come to mind when I think about them.

As a matter of fact, I'm terrified by them.

With burn in, they were tamed a little, but not enough for me, or my ears respectively.

I will explain - They are described as  'metallic'. They are detailed but not airy and at times unlistenable.

They sound very artificial and overemphasized. They are very peaky shrill. Cymbals for example, sound like a sharp knife, piercing your ear.

I have adjusted to this pierciness slightly, but even if I ignored the lack of midrange, this I can't ignore. Just no. Whenever there are highs, they are harsh. You expect it. You know its coming... I'm stuck with these phones until Christmas, but for anyone considering these, who listens to instrumental music, with female vocals of any kind, do your ears a favor and avoid this headphone at all cost.


Score 2/10 





Same problem here. Especially with female vocals. These phones are sibilant as anything.

Also, the vocals are not particularly detailed. They are very 'uninviting' shrill and unnatural. 

With male voices, they are fine, so again, if you only listen to hip hop or rap or such, this does not concern you. There will still be some minor sibilance though.

Basically, if you listen to any high-pitched vocals or anything that is high-pitched in general. Avoid. Keep walking and don't look back.


Score 2/10





For closed-headphones, the soundstage is good, still a little bit clustered/claustrophobic.

In the genres, where these excel, it is really good [again, for a closed can] as well as for videogames.

The soundstage is nicely defined there. I wouldn't call it 3-D like, but its ok.

But for their size, you might still expect a little more from them, in terms of width and depth.


Score 6.5/10





Instrument separation is fine.

But, due to the prominently V-shaped signature and over-aggressiveness, the instruments are hard to follow and seem kind of clustered together.

Nevertheless, they are nicely defined. Some are much more pronounced than others and due to the recessed mids, you might have a hard time when trying to hear all the instruments.

Chances are, you won't be able to. But since this is not the main focus of these cans. I will say they still sound fun and exciting.


Score 5.5/10





Now what I mean by this is how revealing/forgiving are these of bad source material.

Many people stated that these are very unforgiving of bad source material, but I would say this is not entirely correct.

It largely depends on the song itself. For example some songs sound good no matter what the bit rate, while others sound harsh even if they are of higher quality

This is probably largely doe to the 'S-LOGIC' proprietary technology. I was not able to figure a specific genre where this was more apparent. But with older songs the harshness seemed to reveal itself more.

In general, however, they are pretty unforgiving. The problem is, that with worse recordings, the treble and highs are further exaggerated making these songs virtually unlistenable.


Score 4/10





I think I made it pretty apparent that these headphones are highly inconsistent.

At one time, I find myself enjoying them greatly, but at the next I find myself in discomfort, with my ears ringing.

This leaves quite an unpleasant listening experience, forcing you to make a playlist of a few selected songs which sound good with these cans.

Long story short, the only consistent songs are the ones that are either bass-heavy or highs-shy.


Score 3/10






- great build quality

- good accessories

- good comfort [for some]

- easy amping

- rap/hip-hop/electronica master

- great bass

- awesome for gaming

- good for portable use

- detachable, good cables



- overly expensive

- inconsistent

- harsh treble

- shrill highs

- recessed midrange

- discomfort [for some]

- unforgiving

- instrument separation

- narrow headband padding





Overall score 5.5/10





4 months back, I bought these headphones thinking they were just what the doctor ordered. Sure, back then, they were exactly what I crawled for. But perhaps my listening preferences have changed since back then or I simply chose the wrong headphone after all. The thing is, as of now I don't like them nearly as much as when I originally bought then... The new toy syndrome faded away... and now I don't enjoy my music with them anymore. They are still great for videogames though as well as decent enough for portable use and the music genres I mentioned above.

But my ears don't like them and neither do I anymore.

That's why my next set of cans will be the more neutral and 'boring; HIFIman cans be it either the HE-500 or HE-500, I simply need something much more relaxing, less fatiguing and something that will make a good all-rounder.


Also, this is of course subjective and my opinion is only there to steer you in the right direction, if you so desire.

This is also my first review, so please be tolerant.







I gotta admit they are pretty though




The very last photo



Please, post your impressions and opinions on the Pro 900. I know there is an appreciation thread, but not for me... anymore amyways.


Thanks for your read.

Best regards, Luke


Pros: Great Bass, Good for Popular Genres such as Pop, Rap,RnB, sparkly highs

Cons: sibilance on some tracks, midrange is a bit recessed, leak a bit,

These are my first pairs of audiophile grade headphones. I jumped from crappy ibuds to this. This review will contain some detail but not much.


Build Quality

These headphones feel solid out of the box. They are made from hard plastic not cheap plastic but proper plastic. The only compliant I have is the swivel joints can make a bit of sound and is not smooth enough for my liking but I can assure you they are solid.



I think this is where the headphone lacks a bit. The velour padding on the cup and the headband are pretty soft but I wish the padding would compress a bit more. The clapping force is pretty strong out of the box(btw i have a small head) but they will loosen up over time. I found this problem where if the top headband was not positioned properly it hurts the top part of the head after half an hour, this won't happen if you place your headband properly.


Sound Quality

Straight out of the box they sounded better than my ibuds but they didn't WOW me like I expected it to.


After around 5 hours of burn in.



WOW. The bass on these headphones are amazing. They are very tight, detailed, impactful and extends well. THe bass is top notch. On dupstep and electronica tracks I feel like i just WANT TO DANCE. The only compliant i have is that they lose some detail down in the sub bass region and on some tracks can be a  bit overpowering.



As we all know the Pro 900s has a V shaped sounds which mean recessed mids. The midrange on these are recessed compare to the bass and treble but will gradually come out after around 70-90 hours of burn in. They won't end up with a flat response but will help cure the V shape to some extent. The mids are detailed and great sounding. They tend to lean a bit to the warm side, but i wish they could be a bit warm to suit my taste.



The treble are these headphones are sparkly and detailed. I don't find this headphone harsh at all although on instruments like the xylophone it can have a bit of sibilance. The treble is fairly smooth but will sound grainy on bad recordings.


Music Genres

These headpones works great with popular genres such as dupstep, pop, Rnb and such. I love listen to Ne-Yo on this as the bass is strong but not disturbing the vocal and for the first i heard the background singers. These headphone are fast works great with fast bass lines and bass drops on dubstep.


On genres such as rock, the lack of midrange  might make the headphones feel a bit less energertic on guitars. But these clearly separates the instruments and the vocals and have great positioning.


On classical genres, the headphones have a great and wide soundstage. The positioning of instruments are fairly accurate though i think these lack a bit of depth in the soundstage.



 I don't feel the surround sound of the s-logic to a great extent(maybe cause i have small ears). I heard that s-logic works for some people but not for others.  To find for information you might want to go on the Ultrasone Pro 900 Appreciation thread.





Don't listen to low quality tracks on these. These are revealing headphones and will definitely reveal impurities in low quality recordings. I recommend source above 256kps, but if possibly please go for FLAC or 320kps.



 These benefit greatly from a properly amplifier. I using the O2 amp btw. These might be rated at 40ohms but I assure you everything is better when there is proper amplification. With proper amping the bass tightens even more and extends a bit more. The mids are more detailed and overall more clear sounding. The highs extend more as will and will become smoother. 



Overall I would definitely recommend this headphone if you listen to popular genres and want a fast sound. For other types of music these do great with them but not as good as other headphones in this price range. This headphone is very clear sounding and revealing.


You can find these in America for around $330USD. It cost me $439 because i purchased it locally in Australia.


Pros: unreal with techno

Cons: Hot treble

Love my pro 9's. Best headphone out there in its price range.


Pros: Excellent sound precision, deep impact-full bass, detailed mids and high, excellent build quality

Cons: Can be tricky to get situated on your ears with S-Logic



So, this is going to be a more, let's say, “specifically special” review. I'm relatively new to Hi-Fi gear, but I know a decent amount about audio engineering and production. As I was looking into what headphones I wanted to buy, I found out that was a really tough thing to do. I listen to dubstep, per se, along with the similar glitchy electronica variations. But (I'm going to try and say this as least hipster as I can), I listen to really, really underground dubstep. There's mainstream (brostep like 99% of UKF), the leading underground (like Biome, Mala, Burial, etc) which are very “down low style” dubstep, and then there's the songs that nobody knows and are really only found on Soundcloud and scattered on miscellaneous YouTube pages. That's where I find songs I like. And it's a pain in the ass to find good songs, let me tell you. Before this starts sounding pointless, assuming it already doesn't, the music I listen to combines the “down low” of classy dubstep with the “excitement” of more popular dubstep and does so in a very melodic way. The mids and highs are there to create a feeling and the bass shoves that feeling down your throat. So, when I was looking for headphones, I didn't know what would fit my needs.



As for the “specific” nature of this review, I will be focusing on the style of dubstep I listen to and how well the headphones suit it. With that, the headphones are adjusted or, rather, tweaked for that reason. I have done Kees' mod, but I only put felt pads on the back wall and on the driver plate (I suppose would be what it's called). I tried it out with the cotton pad, but that just killed everything I liked about the bass. I have about 60 hours of burn in on them so far. It's been said before and I'll say it again, these headphones REALLY need a burn in. After the first day, I was about ready to return them. But even after just 60 hours (most people say 200+ for complete burn in) they have improved incomparably much. I will reserve a post under this review to comment in a couple weeks after the burn in is complete. I will be powering these phones with a FiiO E17 being used as a DAC through USB from my PC. And with all that hub-bub out of the way, I'll get started.



1 week old Ultrasone Pro 900s with approx 60 hours of burn in and the “felt pad” part of Kees' mod.

Fiio E17 being used as a USB DAC + AMP (+12db gain) (35-42 volume) (0 Treble) (+4 Bass).

Foobar2000 with WASAPI and flat EQ.

Songs are 320kbps CBR, 44.1k, 16bit, mp3s.




Songs being analyzed. (And a little description as to why. I'll go into more detail during the testing)

Vexare – Clockmaker (bass + mid range emphasis)

Hulk – To The Stars remix (low low bass + low vibes + vocals)

Biometrix – Running (bass + wobbly goodness + vocals)

Mitis – Don't Know (bass + huge mid range sounds + extremely complex background sounds)

Mitis – Elevation (progressive style bass + high wobbles that drop into low bass very rapidly)

Mitis – Identity (for being the most beautiful song of all time. And bass)


Build quality

These things feel awesome. I wouldn't expect any less from a German manufacturer than to build top quality durability with looks and functionality. They are made of that really good plastic that America, apparently, hasn't yet accepted as being better than metal for such things. The pads are are paddy and stuff (and there's an extra pair). The adjustable-ness of the headband is very solid; it stays where you set it. The removable cable port is strong (which is a really good thing) with no wiggle. So, yeah, they're German. What do you expect?







This is kind of tricky. They aren't uncomfortable. But, they aren't very comfortable. Due to the circular nature of the cans, there's not really an area where your ears can be so they aren't touching something. And, due to S-Logic, there's only 1 area your ears CAN be so that you're getting the most out of the technology. So, there's quite a bit of adjusting them over and over and being finicky about how they're sitting. Or maybe, I just have a previously unknown OCD regarding circles and ears, I dunno. But, I can usually get the correct placement and just hold them there. I don't wear my glasses while I'm listening to music, so it's not like I have anything else to do but nod my head, close my eyes, and imagine all the decibels are little warriors of the Trojan war trying to break in to my head. Because my name is Troy. :D





I'll have a mini talk about the different frequency ranges and then I'll have an “overall” summary of them. And then I'll go on to talking about the actual songs I'm testing.


Lower Mid Range (150hz – 1000hz)

I like to think of this range as the “perfect sounds” range. These are those dark piano notes that just seem to get you, know what I mean? In any case, this range is very, very important to me. Other than the bass, it's the main part of the song in a lot of the music I have. With the Pro 900s and the E17 (which has a good mid range emphasis), there's just so much detail... so much. Forget anything you've heard about the mids being recessed, I don't know what they were doing wrong. The mid range reaches out and touches you and then falls back into place with graceful pleasure. Piano notes hit strongly and fade away quickly. Wobbles move up and down without any “friction” from interference with frequency change. The range is clear, detailed, quick, and versatile. It stands out from the commotion above it and builds on top of the bass from below it.


Upper Mid Range (1000hz – 3000hz)

Normally, these frequencies aren't kept separate from the previous ones, but just keep reading. I'm not going to explain myself while explaining myself. This range marks the end of the “dubstep noises.” Mostly. You don't really see wobbles or heavy frequency modulation sounds past 2khz'ish. And, with filter or pitch LFOs they extend up and down from 3khz to 1khz. The kind of sounds in this range would be the very agitated sounds that old people find disgruntling. But, with the agitated nature of these sounds, they need to have a bit of control. It's more tough to pair bass with the lower mid range, so when there's an emphasis on this range, there's usually some wubwubwub'ing that matches it. Ultrasone must have had me in mind when they made these, because this range has just a little bit of space to it. It's tough to explain, but, along with being incredibly detailed and vibrant, there's also some extra room in there for the bass to come in without disrupting anything.


High Range (3khz – infinity and beyond)

Everything past 3khz tend to be the rhythmic bits of the song (hats and claps and snaps and such) and lots of overtones. Overtones errwhere. Upon looking at the frequency response graph for the Pro900s, I got a little worried seeing that they got really happy at 6khz. I don't particularly care for 6khz. We've never liked each other. That said, I don't really notice the spike. I used to notice it, but not anymore. Whether it settled down with the burn in or there's just too much going on below it for me to pay it any attention, I'm not sure. But, the entire high frequency range is relaxingly supportive. “Oh, but Troy, everyone says the highs are super bright and harsh. Get outta town!” (that's how you guys sound to me in my head). Well, yes they are bright. Since the burn in and Kees' mod, they aren't harsh at all, and brightness doesn't have to mean that they stand out over everything. With frequency modulation, there's a lot of importance to overtone quality. I don't want to get really technical here, but if note A at 440hz is a square wave (I love square waves), there's lots of maths and physics going on and it's also producing a note at 1.3khz, 2.2khz, 3.1khz, 3.9khz, 4.8khz, etc. And these are all very important in frequency modulation because you can pick and choose which overtones you want to mess with and do fun things with them. Long story short, the brightness of the Pro900s accents these notes very well. Being overtones, they are paired with lower frequencies, but they don't stand out over them at all. These are sort “side sounds” off of the “real sound” and they are there to add to them in neat ways and that's exactly what they do.


Upper Low Range (80hz – 150hz)

I saved the bass for last. This is where the kicks are and some wobbling will occasionally be put in the mix to try and permanently damage your hearing. Other than that, though, this is where the “backbone rhythm” of the song is. Kicks will emphasize a large sub bass coming in along with keeping the rhythm. This range is actually the most boosted part of the phones, as far as the frequency response is concerned. But, here's the thing... there isn't too much of the mid bass. And this is coming from a guy who is a big fan of sub bass. It's actually kind of soft feeling. But impact-full too. Lots of impact with care. It's like a pillow fight with Tempur-Pedics. The bass rolls around really well and noticeable as the size of the bass is awesome. With all the loving care that it boasts, it doesn't intrude on the mid range at all. It stays behind it and plays nice as the backbone that kind of keeps the rest of the song in check.


Lower Low Range (20hz – 80hz)

Awwwwww yeahhhhhhhh. Okay. These are not sub-woofer headphones. If you're looking for something that will squeeze your face sideways and be a force of Zeus, the M-Audio Q40s are a nice choice. The Pro900s aren't like that. At first, I wasn't sure what to think about this either. Before these, I was using phones with D2000ish sub bass levels. So, when I popped the Ultrasones on, the first thing I thought was “where's all the damn bass people were talking about?” Oh, it's there. But, it's not a prideful bass. It doesn't want to bully you, it doesn't want to force you to do something you don't like. It wants to help you. Let's see, how can I explain this...? Hmmm... Well, first off, the sub bass part of dubstep is very, very important. There's all the stuffs going on above it creating a song as songs have always been songs. And then, the sub bass comes in and adds a new element or a new sense, if you will. I'll put it this way. Without the sub bass, the rest of the song is playing and creating a feeling or emotion in your mind. With the sub bass, one of your other 4 senses (touch) also comes into play. The song is touching you. Now, both physically and emotionally. Think about that. The short range of frequencies that the sub bass covers has so much meaning to it. With as short as it is, the most needs to be made out of it. We can't just have everything below 60hz being an earthquake. What Ultrasone has done with the bass on the Pro900s is something I have to use metaphors upon metaphors to try and explain. It's a wonderful creation of sound. The depth of the bass is staggering. We all have felt what 30hz feels like, but do you know what 30hz sounds like? It's a deep cry of sadness. The sub bass on the Pro900s has a mind of its own. Don't get me wrong when I said these aren't earthquake sub-woofer headphones, though. There's plenty of push from the sub bass, but it's the sound that's really special. Not just the feel.


All the Elements Combined

With all this commotion, you would imagine it may just be too much. And that would make sense. If these weren't engineered by the Germans, that probably would be the case. I think the REAL final piece of these phones is S-Logic. I really do. And you can easily tell by moving the headphones around (or just flip them). As you move them forward, the bass starts to muddy up with itself and the treble and mid range go into hiding. If you move them backward, you're just going to have more treble than you know what to do with and there will be no bass to comfort you. My knowledge of S-Logic is pretty basic but, from my understanding, the groves and cuts in the driver spread out and channel the sound. I imagine that statement doesn't give it justice, but that's the gist of what I get. As opposed to all these sound coming from one place, they are separated by the driver itself and channeled a certain direction. If your ears are in that direction, you are given an amazing sensation of sound. All the frequency ranges seem to compliment one another. I never hear fighting between them and I can always distinguish the sound they are playing. Ultrasone has a wonderful thing going here that, I think, deserves a lot more credit. S-Logic is that final element that allows all the precision boasted on the frequencies to work together in ferocious harmony. It's simply wonderful.


Vexare – Clockmaker

The piano in this song is very soft. It is used as a subtle background melody as the detail of the mids really is noticeable. The vibes that make up the drop are always pulling themselves around and dragging out as long notes and sound ever so powerful. They vibes pan left and right a lot and this doesn't take away from anything else. The rest of the sounds are solid in place and what needs to be panned gets panned. The glitchy high notes accent these strong vibes with so much precision and distinction. The crashes are smooth and clear. The mid bass hits and go away with the vibes for superb emphasis. The sub bass fluctuates with the mid range vibes and pushes deep when the size of the vibes really matter. Nothing overpowers anything else and it all sounds so amazing building up together.


Hulk – To The Stars remix

The guitar and percussion in the intro is all very quick and lifelike. The singing has the perfect amount of air to it and is very clean but forward. The kicks in this song play a big role and, like before, do a solid job of laying the “foundation” for the sounds they emphasize. The highs that glitch around do so excitedly but be sure to stay above all the other notes to just be for contrast. The drop has some of the most complex wobbles I've heard. They are very grimy, but smooth, but powerful. The Pro900s highlight these wobbles so, so well. They move around flawlessly and make themselves sound important. The bass is always changing to fit the vibe and goes deep when those wobbles really just need to hit you. The singing on top of the drop stays completely clear and doesn't get distorted or overpowered by the bass and all the other noises going. The drops is, all around, very complex and the Pro900s fit all the different sounds together just as they are supposed to.


Biometrix – Running

There's a lot going on in that Upper Mid Range here. The singing in this song isn't as natural as To The Stars. It has a bit of computer-ness to it as made by Biometrix. The background bass that comes with a lot of the non drop elements is subtle and stays back. The synth notes are clear and quick. The build up is full of high range frequency changes and isn't ever harsh and sounds far away instead of in front of everything. The drop itself has all the ranges in it. The mid range wobbles are just as smooth as the previous songs and the distinction between them and the big upper mid synths is superb. They don't sound like they affect one another. There's not as much bass in this song as the others. The bass here is used to add depth to those wobbles because those wobbles are supposed to sound intimidating and unavoidable. And that's exactly what happens.


Mitis – Don't Know

Mitis' songs are always super duper detailed. And are prone to sibilance. His songs are the only ones I have ever heard high frequency distortion on before. This song was particularly bad on the Pro900s before the burn in and Kees' mod. Now, 60 hours in, I don't have any distortion or sibilance at all. The sounds that were causing them are soft, clear, and detailed. They caused issues because of where they were actually playing. Slight high range glitches on the peaks of bass waves are, I imagine, tricky. But, as I said, the burn in and the mod completely got rid of the issue. Now, the rest of the song is just full of huge sounds. Mitis likes to use House'ish build ups in his dubstep and the Pro900s handle it easily. The constant punchy bass constantly stays punchy and the constantly busy mid range is constantly busy. There's no interruption for a confusion amongst anything and it flows very well detailed. The drop has one of the most powerful sounds in it I've heard. The scream of the 1khz vibe is huge and just encompasses you and makes you think of bad things. Then, it drops away and the upper mid range wobbles come in a just screw up your world with the bass kicking and roaring as the master of it all. It's all so perfect and I don't really have any other way of describing how well the Pro 900s handle such a powerful drop.


Mitis – Elevation

Similar to “Don't Know” in it has a progressive house intro and build up. There are a lot of sounds in here and, I'm probably starting to get redundant but, the Pro 900 keeps the sounds detailed and separate and the bass solid. The drop is full of frequency goodness too. It goes from lower mids to upper mids and back down and around and all over with different wobbles and vibes. The bass is introduced with a downward swipe of a vibe between the wobbles and rolls off of it with force and precision. Then it changes its attitude quickly when the wobbles come back and let them do their thing while acting as support. The kick adds that element of management to everything and stays in control without being in your face or too kicky and uncomfortable.


Mitis – Identity

110bpm is where's its at. I'm getting into my own production soon and this is where I plan on focusing. It was actually this song that made me realize this is where I most “feel” this kind of music. Mitis is a genius. A professional pianist turned EDM producer. And this song is proof of his genius. I'm going to go into too much specifics of how the Pro900 handles everything. It just does it perfectly as expected, remember that much. The mid range whine takes charge and reaches out for you but doesn't quite get there. The piano plays behind everything while atmospheric elements coat everything. The bass doesn't want to be too pushy as its there for purely for that extra sense of touch and interpretation as the mid range creates the mood. Wrapping this up, the drop boasts quick synths that pop up in front of the rest of the song. They synths are clear and, the whole song is created to perfection by the Pro900s.


Regarding the E17, Kees's mod, and the burn in.

I had the E10 before the E17 and, when I got the E17, the different was instantly noticeable. The bass boost on the E10 just didn't sound good. The E17's is much clearer and useful. The E17 seems to be a warmer style amp and it fits perfectly with the Pro900s. The bass and mids are brought to their full potential and the whole frequency range seemed more “at east” than with the E10s. The felt pads on the back smoothed out the effects of the bass, it seems, with the added mass. The felt pads on the driver cover smoothed off the highs and made them appear more natural and relaxed. But, with these 3rd party tweaks, the most important is the burn in. From everything I've read, I'm not even half way through the full burn in and cycle and yet I can tell you, these thing change A LOT. Due to the technicality and precision of it all, it really has to work itself in. At first, the high were really harsh, the bass was muffled, and the mids were too laid back. Just messing around, I set up an EQ to try and see what could be done. I had the bass ranges at like +2db, the mids at +1.5db and from 1khz-10khz I had brought down 1-3dbs depending on where the harshness was. As hours were put on them, these adjustments were brought together into a flat line as they kept becoming more and more balanced.





This has been a bit long winded, but I really wanted to be thorough in why and how the Pro900s suit EDM. So, to wrap it up quickly, let me just say that these are perfect for dubstep. You can try and take my explanations and see if that's what you're looking for in similar genres, but I really don't see how the Pro900s would be as beneficial to other genres as they are to electronica. The bass is deep, precise, and magnificent. The mid range stands out on its amount of detail and moves around flawlessly with quick pitch and frequency changes. The high range bright enough to not get left behind by the other ranges and just bright enough to play the “outside role” of accenting the lower frequencies.


Audio quality – 5/5

Comfort – 4/5

Design – 5/5

Value ($335) – 5/5

Overall – 4.8/5


Post introduction.

I hope you guys enjoyed reading this. If you have any questions, comments, or concerns, I'm more than happy to talk and open to criticism. So, feel free. I hope to be spending a lot more time with you guys as I continue my interest with audio and start getting into production myself.


Links and references.

My imgur gallery of the phones: http://imgur.com/a/eUfTC#0

Mitis' Soundcloud: http://soundcloud.com/mitis

Hulk's Soundcloud: http://soundcloud.com/hulk/

Biometrix's Soundcloud: http://soundcloud.com/biometrix/

Vexare's Soundcloud:http://soundcloud.com/vexare/


Take it easy, guys.



Pros: Fun sound, great bass, super-detailed highs. Simply awesome for EDM and rock and metal. Drums and electric guitars really come to life.

Cons: Can be expensive outside of US, need amplifier to sound great. Not really good for portable use.

Really good headphones. I have used them for about ~ 70 hours now and I love them.

If you listen to electronic music, it's hard to find better headphones. Really awesome and fast bass that provides a good punch without messing up the midrange and the rest of the sound. Ultrasone has a kind of special sound, hard to describe, but for me it took a while before I became accustomed to the sound. If you are looking for a balanced and "neutral" sound, you should look elsewhere, since Pro 900 is far from neutral.

I listen mostly to progressive rock / metal where a fast and punchy bass is important, (at least important to me). While they are best for EDM, they do really good with rock and metal as well. I must say that Opeth sound great with them. Never heard the drums this good and the guitars really come to life! Especially in these genres, they are better than my AH-D5000 because of the faster and punchier bass. The midrange is somewhat laid back, but very detailed. This is the Pro 900's biggest drawback for some people if they want a forward-sounding midrange. To me it's no problem at all, I like it. The highs can be somewhat harsh with the wrong source and if you are sensitive. I believe that an amplifier that has a neutral / slightly warmer sound would suit Pro 900 better since they are already pretty "cold" sounding. The soundstage is wide and deep for a closed headphone.

A good amplifier is important. From an iPod they're actually horrible, but with a better amp and DAC they will open up and shine! Quality songs are important as well. MP3 files under 320 kbps or so should be avoided since they really show defects in compressed files.

They are comfortable, but the placement on my head can be a little sensitive because of the S-Logic that Ultrasone uses. It usually takes a while before I get them on and find the "sweet spot". But when they are on, I can wear them for hours. Price is a bit too high in Sweden compared to the States.

Works awesome in games and movies as well. Battlefield 3 sounds really great now!

They are a pair of really fun headphones.

Ultrasone PRO 900

PRO 900. The Acoustic Majesty of Professional Grandeur. The first Ultrasone PRO headphones with the patented S-Logic PLUS technology. Enjoy unlimited sound performance. Trust your ears. New Titanium drivers S-Logic PLUS technology Ultra Soft detachable Cable Diamond-cut Aluminium nameplate Velvet earpds in BLACK & SILVER Hard sided transportation case Neutrik connectors. Short description Foldable, closed-back professional headphones with new Aluminium nameplates New PRO Box (hardcase) for safe transportation and storage, incl. accessories Technologies: S-Logic� Natural Surround Sound MU Metal shielding (ULE-technology) Safer hearing PRO Box contents Professional headphones 2 detachable cables: one straight (length 3 m), one coiled (length > 3 m) with gold- plated jacks 6,3 mm and gold-plated adapter 6,3/3,5 mm Spare pair of speed-switch ear pads Demo CD Instruction manual Technical specifications S-Logic� Natural Surround Sound Dynamic principle Frequency range 8-35.000 Hz Impedance 40 Ohm Sound pressure level 94 dB MU Metal bufferboard, reduced field emissions in accordance with ULE (=Ultra Low Emission) standard Driver 40 mm titanium-plated Weight 295 g (without cord) Long-term availability of spare parts.

FeatureNeutrik connectors
Height9.05 inches
Length11.22 inches
Weight2.64 pounds
Width3.54 inches
LabelUltrasone Inc.
List Price$599.00
ManufacturerUltrasone Inc.
Material TypePlastic
Material Type Set ElementPlastic
ModelPRO 900
Package Quantity1
Product GroupCE
Product Type NameHEADPHONES
PublisherUltrasone Inc.
StudioUltrasone Inc.
TitleUltrasone PRO 900 S-Logic Surround Sound Professional Headphones - Black
Batteries Included1
Is Autographed0
Is Memorabilia0
Special FeaturesThe PRO 900 offers professional and unlimited sound performance. This is the first pair of Ultrasone PRO headphones with the patented S-Logic PLUS technology. Enjoy the new standard and trust your ears... S-LogicTM Plus is the newest advancement in the S-LogicTM Natural Surround System. S-LogicTM Plus profits directly from innovations developed for our flagship Edition range, the ultimate headphones for critical listening. This sophisticated new technology combines precision dampening with micro-ac
Model Name/TypeMPNEAN/UPC

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