Sennheiser HD 650 Headphones

As much as I cannot understand the overwhalming positive reviews of these headplones I admit that I actually can understand that people can get in love with their pleasant and forgiving sound. If you wish to get close to the soul of a recording however, you should go somewhere else because HD650 are neither natural or neutral sounding headphones. Compared to some other cans (AKG k70x or Beyerdynamic DT880 namely) these Senns are muddy to say the least and lack sparkle, transparency and sheer excitement. The bass is more prominent than with k701's but the definition of the same is not as good. Listening to the HD650 I really miss the sparkle and the excitement that should be there. When listening to accoustic music and classical there is no air at all. A huge amount of information, upper harmonics are simply absent.  It is important to say that I have had some issues with my pair. One of the drivers broke after three years of use. The paint on the headband started chipping after 2 years.
 
However I can understand that many people get in love with their sound. They sound "relaxing" in their own way and are very forgiving on the quality of the recording. The problem is that you can get all that and more at half their price.
 
Amplifiers used: Lehmann Black Cube Linear, Musical Fidelity X-Can v3, Matrix M-Stage

A former boss was an audiophile with varied amps and headsets. I tested, then backed up my pick with reviews from this very forum over a decade ago. My 650 is still my daily driver and it doesn't mind cheaper amps from FiiO. I have been using an E12K MB and sometimes an E10K for specific applications. I found I don't require a fantastic amp as I can combine with PulseEffect profiles and convolutions.

I'm nothing but delighted with the range of this headset. Balanced bass, crisp vocals, clear instrumentals, and it doesn't skip a beat on busy pieces. I also use vocal free electronic music and epics when working to avoid distraction. It amazes. Also after 11 years the build quality has surpassed expectation.

However..

I noticed the HD650 consistently on sale and recommended it to a friend. I was devastated when he complained. His headset is only marginally better than my Platronics Gamecom 780 with PEQ/Atmos. I'm unsure if it is a bad sample or an explanation of the consistent "sale" going on for this headset. I've asked him to return and review this forum instead...

I'm a noob to high quality audio equipment. I have been using V-Moda M-80's. I bought these because they were onsale for $272, and it would be stupid not to buy them at that price. I just opened these up and put them on. I understand that these may need to be broken in first. One of the biggest positives I noticed right off was the level of comfort. These are extremely comfortable, like I have pillows on my ears. The quality of the vocals is outstanding. The music is so much more crisp. Now to the negatives. Compared to the M-80's the sound is so much darker and subdued. The sound from the M-80's is bright and loud. No amp is needed and the M-80's can easily damage your hearing. With these, the music seems to be playing in the background. That's the only way I can explain it, like I'm listening to a recording of a recording. Maybe someone can explain this to me, and what I need to do. These also don't play very loud. I assume I will need to buy a dedicated amp to power these.

This is my second round with these "holy grail" of headphones.  First time around I was just laughing at it's meager power capability.  The sound was good, but not mind blowing.  Zero sub bass control, with ok bass.impact.  I got the Hifiman 400i and couldn't be any happier.  Has everything that I'm looking for at an "affordable" price.  I got a lot of heat from my fellow headphone enthusiasts for my nonesense.
 
  I listen to all kind of music and DO NOT like to be limited to what I can listen too from my music library with an expensive headphone.  For 300+ dollars I want my subbass and bass with authority.  At the same time I want it to be super smooth with stuff like Enya, Enigma, Grace Memo, etc.  
 
So back to the HD650.  It sounds really good when hooked up to my EQ and sound processor.  Without them it just sounds ok with EDM and such.  I don't need to repeat what others have already said about how good it sounds with their music library.  I'm just saying that with modern music, this headphone takes just more than an amp and cable upgrade to eek all the sound out that it's capable off.  For less money you can get a headphone that can do more with less hardware.  
 
So I hooked up the HD650 to the NAD 2140 amplifier speaker output.  Resistor value of around 347 ohms in between headphone and amp.  Sound goes through my good ol' Ibasso D7, into Henry engineering Matchbox, through Behringer virtualizer, Rane EQ and then through the NAD.  That is what it took to get the best out of the HD650 to get the sound out that comes close the the Hifiman 400i that I jam on most of the days.  The subbass came out and the bass had good impact.  The mids and highs are always there ofcourse.  But Sjeesus, I can enjoy the Hifiman with a smaller amp, whereas I can't really enjoy the HD650 without all the other stuff.  
 

I don't like this headphone. Or rather I don't enjoy this headphone. But I can't deny it's impressive.

Plagued with the typical Sennheiser problems of being built cheaply and being overpriced, yet it's really the only in its class, the audiophile's favorite.

That warm and dark sound, that you can never get tired of. That impedance curve that makes it scalable. This is the audiophile's dream, it may not be relevant today with all the FOTMs but it still remains a classic. Grab one used from the classifieds if you're into this kind of sound.

As someone who is into accuracy, it was natural that I prefer the HD600... the HD650 was too thick in the mid-bass and lower midrange and the highs was rolled off, but the roll off wasn't really bad as the clarity is there, but the veiled like sound comes from the mid-bass and lower midrange.

Some complain that it's slow, I disagree, it's pretty clean and fast, but not harsh. Technically impressive, very low distortion.

Recommended!

I moved from IEMs to full sized headphones, and the HD650s were my first real investment. My first "real" audiophile big can was actually the Audeze LCD-2s, but I never had proper amplification back then. As a result, I never experienced what the LCD-2s could actually deliver. I ended up selling my LCD-2s and then going back to IEMs, all the way until this year when I took the dive and tried to buy the safest, most solid cans set I could. I went for the most famous, solid buy and went hunting for the best amplifier match. This, of course, led me to the Sennheiser HD650s.
 
My chain ended up looking like this:
 
Foobar2000 with WASAPI Event, FLACs > Schiit Modi DAC > Bottlehead Crack + Speedball Upgrade (with Tung Sol 5998 Tube) > Sennheiser HD650s (Silver driver)
 
THE STAR-RATING
 
I have been beating myself up over whether to rate the HD650s with 3.5 stars or with 4. If I really could choose, it would be a 3.75/5. However, I am marking in a very difficult manner; I have tried out a handful of good headphones and so it would take a lot really wow me. A 4-star rating would be a "wow" but with a few reservations here and there. So, a 3.75 is a very good mark; it is just short of a "wow." The details with the little green bars are a little more informative of the way I feel about the HD650s (EDIT, the green bars seem to be very inaccurate when I save the post. Instead, here are the scores: Audio Quality (B+), Comfort (A), Design (B-), Value (A+).) With that in mind, let me expand on my experience with the HD650s.
 
FIRST IMPRESSIONS
 
At first, I thought the HD650s were absolutely dreadful. The bass was extremely floppy and bloated. The lows were absolutely non-existent. Treble and highs were slightly tinny, but mostly just very unrealistic and slower than a snail (it seemed like there was long decay on treble and highs). I was very concerned and posted in the HD650 appreciation thread with my impressions; I wasn't sure if I just didn't like the sound, or if there was something wrong. And, given that the Crack is a DIY amp, I also went on the Crack forums to try and figure out if there was a serious mistake. 
 
Well, there was a big mistake. The headphones and the tubes in the amplifier were not burned in. I'm a very scientifically inclined person, and so I have always been very skeptical of burn-in. But after my experience with my setup and burn-in, I am now a 100% believer. The difference was so enormous that I am not sure how anyone could deny the existence of burn-in, at least for tube amplifiers (I don't expect it to be very real when it comes to solid-states) and dynamic phones like the HD650s.
 
After about 30 hours of burn-in with pink noise and various music at slightly higher than listening volume, suddenly the lows appeared. The bass tightened up tenfold, and the treble lost its sibilant ring. The mids, for the most part, sounded the same, though they were never really atrocious to begin with. 
 
THE DESIGN & COMFORT
 
The design of the headphones is simple, but they look professional. The biggest problem I have with the HD650s is their construction material. I was very disappointed to find out that the headphones are made out plastic, and plastic all over. This doesn't mean that they're flimsy, but I wish there were more metal on the headphones. If you look at the picture of the HD650s on the HeadFi reviews section, they look almost metal. The reality, however, is that they're almost entirely plastic and a lot lighter than you expect. The headband comforter is also not premium; for instance, the headband on the HD598s seem higher quality.
 
The clamp force on the headphones is great. It's a little strong, but it's better to be strong and loosen over time than be loose from the get-go. The earcups are quite large and will fit around even the biggest of ears. 
 
SOUND QUALITY
 
My reference point has primarily been my experience with the Shure SE535s, Earsonics SM3 V1s and the Westone UM3X in-ears. In terms of speakers, a set of JBL LSR2325p studio monitors. The rest of my can experience has been with lower end headphones (like the ATH-M50s), Shure SRH750DJs and a bunch of lower end Sennheisers. Indeed, these comparisons are not always fair; each is a different class and will present sound differently. With that in mind, I will try to present my impressions as transparently as possible.
 
GENERAL STATEMENT
 
The sound of the HD650s is really good; however, I would hesitate to call them spectacular (though they are spectacular to people who allegedly enjoy the sound signature). When people say that the HD650s are laid back and mellow, they really are not kidding. I always had a hard time imagining what they meant. The closest thing to "mellow" I could think of were the Sony MDR EX1000s, but the Sonys are more "romantic" than they are "mellow."
 
What I found "laid back" and "mellow" to mean is that nothing is really forward or present with the HD650s. Some people really value this aspect of the HD650s. For me, it did not really hit the spot, but I can respect and appreciate it regardless. Nothing really stands out with the HD650s: everything sounds good, but nothing really jumps out at you as being their focus, or even as being superb. This makes for a mellow and relaxed sound. You will never fatigue listening to the 650s because nothing is being pushed on you. With the 650s, the music is presented gently to your ears, and it makes very good for "just listening" and going about your business. It's probably the best headphones to have on while casually listening, but I believe you will be moderately disappointed if you would like to really close your eyes and feel lost in the sound or if you have high expectations about being swept off your feet. This is because with the way the HD650s present the music, you just know that the music is being played at you and that you're listening through a pair of headphones (albeit a really good pair).
 
THE BASS
 
The bass is very, very good. I just wish it could be 10% punchier, but it does a very good job. However, the HD650 bass really depends on the track. On well mixed and mastered tracks, you will get a very nice bass. It is very controlled and, for the most part, feels "just right." It's some of the best bass you'll be getting if you're not a basshead, and if you're listening to music and don't explicitly want to be jumping around and dancing. I really, really enjoy the bass for any kind of listening except for dance music; it does its job fantastically. However, I believe if it were just 10%-15% more punchy, the HD650s would really be brought more to life. Then again, the phones are supposed(?) to be laid back. It's like being hit with a harder pillow; it's not too soft, and it's not too hard. It's controlled, disciplined and almost at the perfect line between whooshy and punchy.
 
THE LOWS
 
I believe the lows are the absolute best part of the HD650s. If you get a good recording, the lows are just magnificent. Bass guitar sounds just wonderful on these headphones. It sounds very, very natural and even electrifying at times. With the right racks, the lows really carry the track forward and keep you slightly bobbing your head or tapping your feet. This is really where the HD650s shine.
 
THE MIDS
 
I think I have to admit that I'm a little mid-obsessed. If you look at my previous IEM collection, you can tell that I bought IEMs I believed would bring me great mids. The HD650s, although it might be unfair because of how much I like mids, did mids just fairly. I mean, compared to anything else the average person has heard, they certainly are very good. But I do not think that the mids are as well refined as the lows. Keep in mind, though, that some people like the mids the way they are and don't like forward mids, so it is all up to you. That said, here are my personal thoughts on the mids.
 
1. I believe the mids could be brought a little forward. Even if the headphones are not supposed to be uber mid-centric, I believe the mids are just 20-25% off the mark in terms of their closeness. Sometimes a track that is normally really engaging just isn't on the HD650s, and it's because the mids just aren't present as I believe they ought to be. (Then again, personal preference plays a big factor.)
 
2. The mids could be warmed up a bit only because voices didn't seem realistic or natural. Compared to what I've heard on the SM3s and especially the Shure SE535s/530s in terms of vocals, the HD650s made vocals sound like they were just being played at me. I didn't feel like I was being sung to, which makes me very sad because I like it when Taylor Swift whispers into my ear.
 
3. Some people argue that being too forward on anything isn't "natural." But I don't know what is more natural than hearing a singer as if the singer is speaking to you, given that's what it sounds like in real life (the epitome of natural). I could not feel my singer's breath, and I knew that there was a mic between me, the singer and the music. If you've ever heard the SE535s, that's how vocals ought to be done; they are so lush, smooth, caramel and real that you sometimes get goosebumps from good recordings.
 
4. If you're not vocal-mid focused, then the mids will do just fine. In fact, guitar sounds great through the HD650s. B.B. King sounds great on the right recordings, as does distorted guitar in classic metal bands (e.g. Judas Priest, Iron Maiden, etc.) and groups like Paramore. However, the vocals just isn't this headphone's strength; I tried Grammy winning engineered albums and very well reputed vocal albums (including jazz vocals, etc.), and none of it stood out as being outstanding. It's just a fair contender.
 
The mids, as they stand, are pretty laid back. You get fairly good detail, but there isn't a lot of body to the mids. This is perfectly fine for instrumentals, orchestras and a lot of other music, but it is not good for very vocal centric music. The 650s are still quite textured, and so the mids aren't by any means bad. Guitar, especially in classic metal and rock, sounds great. I love guitar through these headphones. However, despite what some other reviewers might say, coming from someone who has a history of hunting for mids, I do not believe the 650s hit the mark on mids if you are someone who listens to a lot of vocals. For instance, running Adele, Taylor Swift, Hayley Westenra or lower voices like John Mayer or Diana Krall(sp?) through any of the mid-kings would be a reliable hit. However, none of these really stood out with the HD650s.
 
This is all to say, however, that "Kind of Blue" by Miles Davis sounds absolutely extraordinary on the HD650s. In fact, I believe it is the absolute best recording I have heard through these headphones; it has yet to be bested. The saxophone is breathtaking. But Miles Davis wasn't known for his vocals, and none of the tracks offer any. But that's why the HD650s did well with it.
 
HIGHS AND TREBLE
 
With my first Raytheon 6080 tube, there was a lack of clarity up top and in the treble in general. Switching over to the Tung Sol 5998s, the highs and treble came out. The highs are never sibilant, but aren't very energetic either. Overall, they are highly satisfactory for most purposes, but I believe things would really come alive or be taken to the next level if you could squeeze another 15-20% out of the HD650s up top. Then again, the HD650s aren't known for an energetic or hot-top end. 
 
The HD650s are not very analytical, but it is enough for you to understand a bad recording for a good one. However, it is forgiving enough to keep everything tolerable, even if not blissful at all times. I don't really find myself complaining about the treble or highs, but I also don't find myself being blown away by them either. The "air" of the HD650s lends great to shimmery sounds, however; it kind of sparkles just enough for you to smile.
 
SOUNDSTAGING & OTHER
 
The soundstage of the HD650s is all right. Some people have described the sound as "three blobbed" and I understand why that would be said about them. The HD650s sound like they have a medium-small room soundstage. The instrument placement in the recordings is good, but I sometimes crave that BIG sound. I thought the HD650s would deliver on that front, but they really aren't that big. The suondstaging is by no means bad, but again not spectacular. The sound is not congested, but you can tell that the music is being played through headphones, rather than feeling like you're there with the music.
 
Instrument separation is not particularly high (but that doesn't mean the HD650s lack a lot of resolution). I think the 650s like to give one coherent, gentle sound rather than ripping everything apart like the UM3Xs or completely punching you with a tidal-beam of sound (as on the SM3s). I think the level of resolution is perfectly fine. I think it could use a nudge more just because, but there is nothing negative to be said here! But this is a good segue to the next point:
 
VALUE
 
You can nab a mint pair of HD650s on the secondary market for extremely cheap. Low to mid 300s before shipping. That is an oustanding deal for such a solid pair of headphones. I bought a winter coat more expensive than my HD650s today, which just helps put everything in perspective.
 
If you noticed, most of my criticisms were wanting 10-25% more out of everything. But I suspect that's what is supposed to be delivered by the next level of headphones (HD800s, LCD2s, etc.) which cost a lot more. For the price, the HD650s are very well justified. And, the truth is, the HD650s should be a staple of every headphone collection (if you can afford to keep it)!
 
CONCLUSION
 
Overall, a very good headphone, but seldom spectacular (except in the lows if you hit the right recording). The headphones sound laid back, and maybe that was Sennheiser's goal. But, if I dare say, perhaps it sounds laid back because it does everything just "well," but never anything more. If you took the 650s and somehow could extract that extra 10-15% from it, it would be absolutely outstanding. The phrase "So close ... yet, so far away" describes my HD650 experience quite aptly.
 
The lows are its greatest strength, followed by the bass. The mids leave you wanting a lot more if you listen to vocals, but can deliver from time to time if you like guitar or non-vocal music. Dance music and electronic music, however, is really off the table. Electronic music is what I listen to the most (not anymore, though, just because of my setup!), but I just don't think electronic music fits well with the HD650s because electronic music is, by nature, a high energy genre, and the HD650s are anything but energetic. They are not energetic anywhere along their sound, and I think that is both what makes them so charming, but is at the same time their downfall.
 
The HD650s, by being so close yet so far away, is just a great, solid listen. It really is the introductory audiophile can par excellence. It does everything well, but not well enough so that you know there is for sure better out there. If you could just push that extra bit of work out of it, the 650s would really be stellar. But, hey, maybe it's just my amp and DAC; perhaps you could get the extra work out of them if you hooked up some multi-grand amplifiers... Then again, if you're fooling around with something like a Zana Deux, Leben or Wine Audio, you probably shoudn't still be listening to the 650s! 
 
Very good, but seemingly always a tad short of spectacular. 

My time with the HD650 was short: bought on Amazon and returned 6 days later.

Prior to serious listening, I 'burned-in' the headphone for 48 hours with constant pink and white noise. This did improve the sound, firming up the bass and eliminating some perceived hollowness.

The thing that struck me first about the sound of the HD650 was its sumptuous smoothness. Vocals especially had this syrupy sweetness which many enthusiasts will like about the HD650, but for me just masked the natural characteristics of the human voice. I find it difficult to understand why recording studios would use this headphone, as Sennheiser claims in its advertisements, when vocal presentation especially, is so obviously coloured. When I listen to a headphone I want instruments to sound as close as possible to 'real life' instruments, timbre being particularly important. The HD650s do manage to preserve some accuracy in instrumental timbre but simply fail on the human voice, where neutrality is traded for chocolate-smoothness.

The overall sound is indeed warm and smooth which is sometimes appealing, but together with the relaxed, sometimes listless presentation, music is robbed of the vitality and vivacity it needs. This does make the HD650s the headphone to go for if you just want to listen to music in comfort for hours on end; but some of us want some energy and excitement - when the music demands it - which these headphones frequently fail to deliver.

Bass is quite deep and usually remains fairly tight, but sometimes sounds soft in some music, which is I think is a consequence of the overall 'plump' warmth of the headphone. And again due to the - for me - suffocating smoothness, the high treble sounds blunted; the HD650s never manage to reach the heart-stopping heights that the female voice especially, is capable of.

As for other qualities...imaging is good but nothing special, nicely formed but by no means holographic. Sound-staging is very good, in fact it can be ruthlessly revealing of poor quality source material in that regard; some of my less than perfect recordings had a 'gap in the middle' effect on the HD650s which was not apprarent on other headphones.

Detail retrieval is excellent. The HD650s are able to pick up background and ambient sounds with ease and elegance, but musicality always taking precedence over outright detail-scavenging.

As for build quality, really disappointing - masses of plastic that has an uneven appearance in certain lights; and they look as if they could easily break or crack if dropped on a hard surface or accidentally sat on.

So I recommend this headphone to someone who a favours a warm, smooth and 'friendly' representation of music. But those who want crave neutrality, realism and energy - look elsewhere.

The praise that has been heaped upon the Sennheiser HD650 headphone is something that probably every headphone OEM envies. The HD-650 is nearly a decade old and yet is still viewed by many as a top tier dynamic, worthy flagship, and is the benchmark that many measure price to performance ratio against.
 
I personally was cruising along quite happy with my set up… Running almost exclusively between Denon D5000’s and Ultrasone Pro900’s. I felt I had the best of both worlds. Since I love the visceral impact of good bass in my music, these two pieces seemed to be perfectly tailored to my listening habits.
 
The Denon gave me a little more reasonable treble energy and a little less sibilance when I needed it for something more complex and diverse. While the Pro 900 gave me that sub woofer for your ear feel that just flat out slams your ear drums. With a decent DAC/ desktop amp set up I am usually able to apply a 6kHz to 8kHz cut to smoothly equalizes the sound to eliminate that “ESSS” sounding ear razor that the Pro900 is so infamous for.
 
However somewhere along the way the constant gushing over the Sennheiser HD650 got to me. Specifically Mike from Headfonia repeatedly claiming that it was the ultimate king of bass impact…. He never said king of bass quality, quantity…. He always spoke of the HD650 in terms of “Impact”.This should get just about any hard core and well funded bass head’s juices flowing and so I began looking at the viable options for acquiring this apparent low frequency giant. And so after parting ways with most of my portable equipment, I was flush enough with cash to purchase my own set of the venerable HD650.
 
I will start out by saying that because of all the talk of the ‘luscious mids’, smooth highs and world class low frequencies my expectations with this headphone were near off the chart…. I have since done the same thing with my first attempt at the  Audeze LCD2. The LCD2 albeit a very good headphone, was so overblown in my mind that by the time I actually listened to it, I was disappointed. That had far more to do with my overblown expectations than anything... because second time around... being aware of how much darker the LCD2 was than its Hifiman counterparts.... I have found a place for the LCD2 in my stable.
 
But by the time the Sennheiser headphone had finally arrived, it was competing with dare I say unrealistic and extreme expectations and was pretty much behind the 8 Ball from the start.
 
Build & Design
 
The Sennheiser HD650 is certainly a dated design. There are dozens of headphones on the market in the same price point that are better dressed. Most $500 headphones have premium materials such as aluminum, leather and wood worked into the build. The Sennheiser headphone is almost exclusively plastic. It is a shiny, cheap feeling plastic on virtually every exterior surface sans the grill, ear pads, retainer ring and bottom of the headband. Detail items like the "Left" and "Right" indicators are simply cast into the grey plastic.... This build quality seems unfit for a legacy flagship.... Obviously its been a long time since this headphone was brought to market and Sennheiser was working in the pre-Beats era, long before headphones were valued as a fashion accessory and long before OEM's thought they could bring flaghips to market with price tags north of $1000. Sennheiser's HD800 and HD700 show they clearly can design a top tier headphone both in sonic character and design quality, but the HD650 is still asking $500 USD and doesn't give you a warm and fuzzy out of the box once you've got it in your hands, at least it didn't for me.
 
The headphone is extremely light. Many in the community would give it points for this and they are certainly entitled to their opinion. However I personally see this as a demerit. Speaking strictly in terms of assessing an items value from a subjective/ aesthetic viewpoint, the Sennheiser headphone appears to be made of cheaper, less durable materials. I am not going to strain my neck if a headphone is north of 400 grams. The Hifiman HE400 weighs in at a hefty 440 grams and is perfectly comfortable to me, the Denon D5k weighs in around 360 and is probably the most comfortable headphone I've ever worn. If one is spending $75.00 on a beater set of portable cans, an expendable gamer headset or a cheapie like Superlux or Porta Pros (of which I am a fan)  then by all means they should be and can be as light as a feather and made almost exclusively out of plastic without raising eyebrows. But at $500 out the door for a would be flagship headphone that was intended for listening at home or in a studio through a serious system... I don’t know.... I expected something more substantial.
 
The crux of this featherweight value is that in order to keep it properly seated on the listeners head, Sennheiser had to crank up the clamping force. Otherwise the light weight construction leaves it prone to moving too easily as it has little resistive value on its own. The clamping force is something that many have commented through the years as a supposed 'death grip'... Once again just like the HE400 won't snap my neck, the clamping force on the HD650 is not going to crush my skull. It is certainly wound a bit tighter than most, but I personally believing the clamping force has been measured perfectly to counteract the lightweight construction's tendency towards moving easily. It is a goldilocks value.... not too much, not too little... Just right. This is a nod to the design engineers.
 
Right off the bat my delusions of grandeur were dispelled. It is certainly nicer looking than its faux marble clad brother the 600 however as a supposed flagship headphone of such universal praise, I was underwhelmed by the look and build quality. Those who think this is immaterial are kidding themselves.... Aesthetics have value to the consuming public and audiophiles are most certainly not immune... The hifi world is littered with glitzy machined aluminum tone arms, satin metal surrounds for tweeters, anodized aluminum face plates with machine metal knobs, high gloss enamel finishes, lustrous wood side panels, frosted glass.. etc....etc...
 
The die-hard says that this is simply an indicator that they chose to pour all their cash into sound quality. OK maybe this is true.... lets see. 
 
Hook It Up! And Wait.
 
I did not want to be hasty with a plug and play attitude as I had heard that the out of the box, plug and play sound of the HD650 was disappointing (I heard this about 10 hours after I purchased it sadly) but that a 100 hours of burn in would get you a somewhat matured sounding headphone, so onto the vintage Realistic 64B it went. This older vintage rig is hooked up in a file cabinet at work and so can burn in a headphone out of site and outta mind while I still enjoy music on my main headphone rig…. A Violectric V100 tethered to a Laptop running JRiver via my Rega DAC with a Wyred 4 Sound uLink handling conversion duties to SPDIF. 
 
100 Hours - Impressions
 
After it had burned half the day on Thursday and all day Friday, Saturday and Sunday by the time I got in to work on Monday the 650 had clocked roughly 96 hours of burn in time. I plugged it into the Violectric V100 and listened to some newer redbook CD rips. Muse 2nd Law, Foo Fighters Wasting Light, and Gaslight Anthem The 59 Sound. 
 
The HD650 is not a bass head can. That is my first impression. Where the hell is this supposed ultimate bass weight?
 
A couple of local Head-Fiers down here in the Southland told me the 650 was really amp picky and that I would do better with a tube amp like a Woo WA6 or Bottlehead Crack. However my headphone amp is a Violectric amp which is what Sennheiser uses in their “Hall of Fame” set up and is one of Sennheiser’s Senior Project Manager Axel Grell's favorite amps for his own listening. A couple others mentioned changing the cable to a Cardas one, and one guy said I might need a different DAC to get the most out of it.
 
So in order to get the Sennheiser HD650 to sound good what I needed to do was:
 

1. Get a different amp
2. Get a different cable
3. Get a different DAC

​
Maybe I should get a different source, different interconnects, a new power conditioner and stop using CD's while I am at it eh? Mind you I do see where some could see this headphone as all they need and build out their entire system around it.... searching for another .5% of improvement with each piece of the puzzle... but I have already built my system(s) and am not really inclined to do a whole lot of kit rolling in order to optimize the synergy with this lone headphone when I have a half dozen others that sound fantastic through the rigs as is. 
 
So my immediate disappointment with the bass could’ve derailed this whole review. I was expecting Pro900 bass or Denon D5k bass without the 7khz ear razors or recessed mids... What I got was an all too polite rendition of EVERYTHING.
 
The low frequencies are extended, there is textural information galore, you can really hear the stick or the tom on the drum skins, the full decay of bass strings, mid range is sweet and smooth, and there is plenty, and I mean plenty, of high frequency detail and sonic information. Anyone who says the HD650 does not have enough treble energy or detail is, to these ears, not hearing straight.
 
But that ultimate bass weight, that Mike implicates all the time, it is not here IMHO.
 
The low frequency, midrange and treble are all recessed quite a bit. They do not hit you in the side of the head with impact. They don't even touch you. If this is what people are speaking of when they say the 650 is veiled then yes, it is veiled, but not in the sense that a certain portion of the frequency range is somewhat blurry or hidden.... Its more about air pressure that makes a headphone felt as well as heard. Open architecture does limit this but I've heard better open backs at giving you punch. 
 
I will hop on my soap box right here and say that one part of a headphone experience that is vital to me, is the overall weight of a headphones tone. I am not specifically talking about bass extension or articulation or even the bass frequencies in particular. What I am saying is that headphones with a tonal density to them…. A robust acoustic mass that move some air pressure to bring the music more to life…. That is critical for enjoying music in my book. Otherwise it sounds like music but doesn't feel like it.
 
It may not be critical for monitoring, mixing or mastering in a studio, or DJing or even for being an audiophile who wants to sample 24/192 and DSD audio tracks like they are a damn 10 year old Pinot Noir… but for the average Joe like myself who wants to simply strap on a set of headphones, cue up an album, hit play, sit back and enjoy some music…. The overall presentation doesn’t need to be “forward” but it needs to be felt as well as heard.
 
Oldies like Buddy Holly, Sam Cooke, and Bob Marley all have strong drums and bass rhythm that is presented most natural when the full weight of the instruments is presented... the kick drum and bass line at the opening of Dock of the Bay sets a strong foundation for Otis and the guitar to build off of. Alternative music like Smashing Pumpkins,  The Pixies, Jawbreaker, Dirtbombs, and Blur all have bass and drums that need punch. Punk rock and other guitar driven music like Social D, Operation Ivy, Van Halen, Bad Religion, The Ramones, Rancid, The Strokes, Vampire Weekend, Weezer, Gaslight Anthem.... they all have rhythm sections, and natural timbre that is presented best when it is presented with a fully developed full bodied sound.
 
Most people would rather listen to music through a great set of speakers because the music can be felt in your bones and people go to concerts because the live performance trumps every other experience. I saw Muse at Staples Center a month ago and the bass and drums absolutely rattled my bones.... Just vibrating you right down to your soul. And that is why 50,000 pack stadiums every night to see performances. Because the music overwhelms your senses. I saw the Ramones in Santa Barbara in the early 90's and it was the loudest show I've ever been to... Large Marshall double stack cabinets for both Dee Dee and Johnny and Marky's drums were mic... all in a small club (The Anaconda for anyone who cares) and the Ramones play tight so it was just a full on sonic assault.... transcendental to a young kid and still the best show I ever saw. 
 
To me, listening at home through a set of headphones should be a tamed extension of that experience. Obviously headphones can't give you what a live concert can... nor can they give you what well crafted speakers can, and speakers can't give you what amps and guitars and mic'd up drums can.... but each should have a measure of the other. The HD650, although tonally sweet and smooth and carrying some weight in its tone is similar but a bit more recessed than the Audeze LCD2, it just holds you too far back from the music FOR MY TASTE. It left me wanting for something more!
 
The HD650 often gets the compliment that "I could fall asleep with these on" and that to me sums up the HD650 perfectly.... It's kinda boring.
 
The HE400/ HD650 issue.
 
I’ve had a few people ask me which I prefer. The HE400 has a little more low end punch and the extra growl and mid range power makes it a better choice for my taste. Speaking strictly in audiophile terms the HD650 has the better acoustic chops. Its professionally damped driver fills out more evenly and more linearly but this linearity is still comes out anemic compared to the more live sounding Hifiman. . 
 
At lower listening levels the HE400 is a far better choice. It gives you a tad more flesh to sink your teeth into. A bit more punch in the low end and a live wire mid range that’s tipped up just enough to make rock music sound amazing. But as we travel up the volume ladder the Sennheiser becomes more stable and stout in its presentation, everything fills in evenly. The lows get stronger as the mids get sweeter etc... The HE400 although good to a point, can get crispy and its budget level planar membrane can start smearing tones and blurring separation on complex electronic fare where 100 or more different sounds are sometimes dubbed over the top of each other. The Senn is more resolving and surefooted through big sonic waves but like said, anemic... I could live with either, but if I could only have one, it’d be the 400. Even though it tends to get a little distorted when it is under powered and doesn't have that furthest reach of resolution. It's rock and roll presentation is more enjoyable.
 
Johnny Come Lately – The X1 P
 
Phillips open back X1 is priced a hundred short of the 650. But there are obvious similarities. Open back design, midrange price point. But one would assume that its beautiful aluminum cups, velvet ear pads, and leather headband come at a sonic price.
 
The X1 is a gorgeous looking headphone. Along with my D5000 and LCD2 it is one of my most sartorially minded. People like to contrast it against the Sennheiser Momentum…. No, the Momentum looks flimsy build and doesn’t hold a candle.
 
Next to the X1 the 650 looks very dated. The plastic finish is a glaring shortcoming up front for a headphone asking $200 more. The 650 is the technically superior headphone. For the same reasons the HE400 can't play this game the X1 can’t either… It doesn’t have that same surefootedness and linearity that the Sennheiser does, nor does it scale as well. But the X1 has a more rich and nourishing tone that will appeal to music lovers and bass heads alike. Its bass slams harder, it's musical vibe is just funner. It can also get a little crispy and sibilant in the upper register when volumes start creeping up whereas the 650 never breaks form. The Sennheiser is still the “better” headphone. But for a music lover like me I am not sure how important that is. Lately the X1 has been getting a ton of head time and that speaks to its engaging tone. It gives me that 'felt as well as heard' sound that I crave.
 
VS. My Favorites
 
Against both of my closed back favorites, the Sennheiser plays the same song. It is linear, well engineered, accurate and anemic. The Denon D5k and JVC DX700 are simply more dynamic more emotionally engaging, and immerse you in the music. They surround you in an envelope of tone.
 
The punch is there with both, but the JVC DX700 ups the ante by giving a sound stage worthy of an open back phone and providing not quite as linear but still fairly linear sound as things get louder and louder. I would choose the Denon and the JVC DX700 over the 650 every time. It simply doesn't give you as much of the song as they do. It is truncated in its presentation it sounds thin and lifeless compared to the two Japanese headphones. They are just too well rounded, dynamic and potent for the 650 (IMHO). They don't give anything away.  
 
Contrasting against the Japanese duo, the Sennheiser strikes me as the stuffy middle aged guy rocking a corporate polo, khakis and cheap patent leather shoes. He presents well enough in professional circles but doesn't really have the personality to charm. The 650 is the middle aged, mid level cog in the machine. The D5k and DX700 are sharp dressed 20 somethings from Tokyo with Italian cut suits and crepe sole oxfords. Their resume may not be as thick and they may not have the same number of professional accolades but they are dynamic, engaging and charismatic. They offer excitement and future glory that you will not find with the hum drum late 40's something sitting with his shoulders slouched in the lobby.
 
WRAP IT UP!
 
In closing the Sennheiser is by most normal youthful standards a little light in the ass. Some would call that a veil or laid back but it’s not laid back to me… That denotes a mellow, relaxing sound and a veil sounds like the treble is shelved down or certain parts are blurry. No this is about sound pressure levels. Air being moved by transducers. This is about 2 dimensional accuracy vs. 3 dimensional involvement. 
 
The caveat to that would be in a full size stereo rig.... In those scenarios the 650 sounds a lot better than most modern 32 ohm headphones.... The only 2 in my collection that best it on the integrated amp scene are my planar headphones... both of which have flat phase response and so don't do the poorly damped thing.... But in a typical dedicated headphone setting.... to me, the 650 is a bit boring. You are held back just a bit too far from the song to truly enjoy it. I dare say that the hype may be a bit overblown….. at the very least it does not line up very well with my taste. 
 
Mind you I didn't write this review to deride anyone who loves the HD650.... and I'm sure those of you that are fans of it will continue to enjoy it. But I do think there are a lot of people running around this site looking for answers, not wanting to spend their hard earned cash poorly.... and most people use this site to inform their future purchases. Because of some of the descriptive words I have heard people use, I think someone could get the wrong idea about the sound of the 650... when people call it dark, warm and full bodied.... I don't know that these words do the phones tone justice. At least not without building your entire system around the HD650. Contrasted against the greater landscape it is a bit light and lacking in body. Someone needs to say that. 
 
So I hope I do not get flamed but I think that someone out there deserves to get a little objectivity on this headphone rather than just more gushing about "greatest ever". No I am not a Beyer or AKG fan boy going subterfuge.. I am just an average consumer with average taste and listening habits trying to give others like me some reasonable perspective. 
 
I suppose if you dedicate all your resources to just this one headphone, you can make it sound spectacular.... But to the average head-fier who has the same low riding, subwoofin tendencies that I do. Who listens to Muse, Foo, the Black Keys, Gaslight Anthem, The Strokes.... modern music.... this may not be such a strong fit. 
 
Just saying.

This was my favorite headphone for some time. Mainly because its the first decent pair I owned.
However as I listened to other cans these became less and less important. Now all I see when I look at them is a plain headphone with dull sound.

I recently used a borrowed HD650 in a balanced system for about a month.

After I gave it back and returned to my balanced Grado HF2's, I was shocked how lifeless the HD650 were.
I must thank Sennheiser for making me appreciate my current headphone.

I was so excited to finally get my hands on the holy grail of mid-range headphones, the Sennheiser HD650... or so I was lead to believe. 
 
Facing facts, we're looking at a relic here. Whether that relic should be viewed through the lens of history as a valuable antique, or as a laughable remnant of a more primitive society, is the question that's up for debate. I vote for the latter. This headphone is soon to celebrate its thirteenth birthday, and in the meantime, the rest of the world has progressed unrelentingly. At one time, the HD650 may have had the chops to compete in the mid-range arena. It was probably viewed as a spacious, warm, bassy "upgrade" to its sterile cousin, the HD600. The fact that it could take a lot of energy from an amp and increase in overall speed and technical precision with the added energy was probably fuel for the fire for gear-collectors and upgrade-addicts.
 
The problem is, when you try to polish a turd, you just get a shiny turd.
 
Alright, I'll be as neutral as I can be starting now. This headphone is a good technical performer with speed, detail, sound stage spaciousness, instrument imaging, and overall can make anyone go "wow" once or twice in a listening session. For $499 MSRP, it had damn well better. Unfortunately, like a fireworks display, you just spent a ridiculous amount of money on something that made you go "ooooooOOOhhhh!" once and then ceased to impact your life in any way for the rest of eternity -- aside from the lightening of your wallet. The exaggerated warmth in the bass and completely lifeless, sucked-out mid range is as quick to take the wind out of your sails as a punch in the gut. I couldn't believe what I was hearing -- side by side, the HD650's little brother, the HD600, had so much more vibrancy and actually made you pay attention to the music. The HD600 had no problem effecting an extremely tight, natural-sounding bass note. The HD650, on the other hand, bloomed the same note to a point where it was impossible to believe they were built on the same stock. The voice (especially male voices) ability of the HD650 was a total downgrade. It literally put a frown on my face to hear my favorite music rendered in such a dull and distant manner, when retribution was only inches away in the form of the HD600. I played both through an excellent $250 amplifier and I refuse to be lead astray that, if only I put another $1000 into the amp chain, it would have started to sound good.
 
Why do people like this headphone? Because it used to be the bassy/warm version of the best headphone going -- the HD600 -- and people like bass? I have no idea how this phone was Sennheiser's  flagship for so long. They completely turned the HD600 on its head and ended up with a monster. It took a pinch of the original technical prowess of the HD600, added a metric buttload of warmth, bloom, lack of intimacy, and sadness; and completely took away the charming and realistic voicing of the HD600.
 
The biggest disappointment is the price and the previous flagship status of this headphone. If the HD650's MSRP was $199, it could get a hearty recommendation for people who crave warmth and don't really look for realistic sound. If they called it the HD500 it might have made sense. As it stands, it is a stain on the history of a solid company. Compared to literally every other mid-range headphone that I've tried that is more modern (Fidelio X2, HE400 to name two), the HD650 is an afterthought.