Sennheiser HD 250 Linear II

Average User Rating:
4.75/5,
  1. xEcuToR
    4.5/5,
    "The Forgotten "
    Pros - •Powerful Bass Impact •Deep Bass Extension •Accurate Imaging •Big Soundstage •Detail Revealer •Genre Master
    Cons - •Discontinued •Laid Back Mid-Range •Availability of Spare Parts
    Disclaimer
     
    This review has been written based on past 2 year’s observations. I am not a part of the audio industry or trade and I represent no one but myself, and this review is written based on my individual assessment of the Sennheiser HD250 Linear II headphones. I apologize in advance if there are any errors or use of poor grammar as English is not my first language. If anyone is offended or does not agree with this review, please ignore it as it is of no significance.
    PLEASE NOTE-No copyright infringement intended. 
     
     
     
    HD 250 linear II
     
    Audiophile quality, dynamic stereo headphone using sealed ear chamber principle. The HD 250 linear II is a dual purpose monitor/audiophile headphone which can either be used in professional studios or at home for fatigue-free musical enjoyment.
     
    • Excellent transient response thanks to its lightweight triple wound aluminum voice coil
    • Balanced, full frequency reproduction gives fatigue-free musical performance
    • Oxygen Free Copper signal cable for strength and contact noise elimination
     
     
    Technical Data
     
    Frequency response                                        5 - 40000 Hz - 10 dB
                                                                                  10 - 25000 Hz - 3 dB
    Acoustic principle                                            dynamic, sealed
    Frequency curve                                              Diffuse-field loudness equalization
    Nominal impedance                                         300 Ω
    Sensitivity @1 kHz                                           94 dB
    Power handling capacity                                200 mW (as per DIN 45582) 
    THD (as per DIN 45000)                                  < 0.2 %
    Sound coupling to the ear                             around the ears (circumaural)
    Headband pressure                                        3N
    Weight without cable                                      215g
    Plug                                                                    6.3 / 3.5 ø stereo phone plug
    Length of connection cable                          OFC-cable, 3 m
     
     
    3.jpg
     
     
     
     
    Introduction
     
    Introduced twice, firstly in the early 90s, then again in beginning of the 21[sup]st[/sup] century, this is the 2nd headphone in the HD 250 series of headphones. The Sennheiser HD250 Linear II is a closed, circumaural, consumer grade, audiophile quality, dynamic stereo headphone.  These cans have been discontinued for a while now so it is very difficult to get one anywhere. You might find it on eBay official or other eBay websites( e.g. Germany, Netherlands,  Greece, UK etc.), but if they appear for sale it is gone in minutes and if it goes for a bid it can go up to $300 depending on the overall condition of the headphones. So basically, very few own it and most of them will not be willing to sell.
     
    This was my 5th Sennheiser purchase after the PX100, CX300, CX550 and HD595. I have also heard the Sennheiser 6XX series prior to the purchase for a considerable amount of time before I decided to purchase these. At the time (Jan 2011) I had two wonderfully engineered headphones at my disposal, the Beyerdynamic T1( Now Sold)  and the HiFiMAN HE5( Kept).  I bought the HD250 Linear II prepensely because after owning a brilliant open and semi-Open headphone I wanted a closed headphone which could perform at approximately similar levels. In the closed category I found there were headphones like the Sony MDR R10, Audio Technica L3000 and Denon D5000/7000 to be the best amongst popular audiophiliac perception.  The first two were out of my budget and they are impossible to get and the Denon line seemed like a bass/mids head paradise, which is not the kind of sound signature I’m into when it comes home/office use. So I stumbled upon this review written by a senior fellow head-fier who goes by the name ‘padam’. This was the only decent review about the HD250 Linear II I could find at that time and I got pretty excited about this headphone. It took about six weeks to find a listing on eBay. It was a bid listing but the seller removed the listing in a couple of days. I got in touch with him and bought the headphones from him.  This was my first HD250 Linear II. Recently I bought another pair which arrived from Germany.
     
    I’m writing this review to give an overall impression of the HD250 Linear II and at the same time talk about the few differences between both( Germany vs. Ireland) the headphones.
     
     
    Design and Comfort 
     
    This is a headphone meant for private listening and it shares the same design pattern of the Sennheiser headphones manufactured in the late 80s and early 90s like the HD 250L/520/530/540/560 headphones.  They are very comfortable for both prolonged and brief use although if you listen for a couple of hours you will feel a bit of pressure on the ears as it hugs on to your head unlike the AKG series headphones (Vintage). Linear II has headband adjusters at both sides which can be very useful for any type of head size. Overall, very comfortable headphones.  Like all the other HD line headphones mentioned above these headphones have removable cable( 3m long, 3.5mm Jack) and they can also fit the HD6XX series headphone wires without any adjustment which increases the number of options when it comes to aftermarket cables.  I myself have used the iBasso Sennheiser balanced wire compatible for HD650 for this headphone and used it with the iBasso Pb2. The original ear pads of the Linear II are very comfortable themselves, made of leather with a sponge interior wrapped around a white cloth. I had to purchase new ear pads from eBay for both the headphones as the original pads were heavily worn out. These are literally all black headphones.
     
    Choice Of Music- On the basis of preference and variability to find out how the headphone performs when different genres of music are thrown at it, I have selected the following albums out of my collection. 
     
    1. Frank Zappa –     Freak Out CD (1966)
                                        Hot Rats 200Gr LP (Barking Pumpkin) (1969)                       
                                        Roxy & Elsewhere LP (Discreet) (1974)
                                        Joe’s Garage (LP) (Barking Pumpkin)   (1979)                     
                                        Jazz From Hell (CD) (1986)                     
                                        The Yellow Shark (CD) (1992)
                                        Civilization Phaze III (CD) (1993)
                                        Omnibus Wind Ensemble - Music by Frank Zappa SACD
     
    1. Sikth - The Trees Are Dead & Dried Out Wait For Something Wild (CD) (2006)
     
    1. Leo Ornstein - CDA67320 - Ornstein - Piano Music
     
    1. Armin van Buuren- A State of Trance (CD) (2007)
     
    1. Kongar-ol Ondar - Back Tuva Future (CD) (1999)
     
    1. Denon Audio Technical CD (CD)
     
    1. Freak Guitar- The Smorgasbord (CD) (2013)
     
    1. Harrison - Concerto in Slendro - Concerto for Violin and Percussion - Labyrinth No.3 (CD)
     
    1. Pink Floyd- The Wall (UK Vinyl) (1979)
     
    1. Best Audiophile Voices “Selection” (24 Bit Re-mastering CD)
     
    1. Ayreon - Universal Migrator II - Flight Of The Migrator (CD) (2000)
     
    1. Bill Evans Trio- Sunday At The Village Vanguard (XRCD) (1997)
     
    1. Igor Stravinsky - Le Sacre du Printemps (1913), BSO, Tilson Thomas (LP) (1972)
     
    1. The Aristocrats - The Aristocrats (CD) (2011)
     
    1. Harry Partch- A Ritual of Dream and Delusion Ensemble of unique instruments (Stereo LP)
     
    1. Conlon Nancarrow Studies For Player Piano (CD) [Wergo]
     
    1. Dream Theater- Six Degrees Of Turbulence (CD) (2002)
     
    1. John Coltrane - Ballads (CD) (1962)
     
    1. Krzysztof Penderecki - Complete Cello Concertos (CD) (2003)
     
                                                 Die Teufel von Loudun (LP) [Philips]  
     
    1. Rage Against The Machine- Rage Against The Machine (LP) (1992)
     
    1. Tool- 10,000 Days (CD) (2006)
     
    1. Eric Clapton - 461 Ocean Boulevard (LP) (1974)
     
    1. Anton Webern- The Complete Works Of Anton Webern Volume 1- Conducted By Pierre Boulez (LP)
     
    1. Edgard Varese- Edgard Varese - Complete Works Vol.2 Kent Nagano (CD)
     
                                      Edgard Varese- Maurice Abravanel Varese (Vanguard) (LP)
                             
    Tonality
     
    In a nutshell, Linear II is tonally a V shaped headphone. The mids in the (400hz-2KHz) region seem to be laid back compared to the higher and lower frequencies.  When it comes to mid-centric AKG headphones like the AKG K141 (600ohms), compared to them Linear II has definitely a laid back mid-range.  With proper equalization and amplification this improves enormously. Overall the headphone has a very neutral sound, not overemphasizing the bass and sounding boomy and the same time not possessing harsh highs. In case of specific albums and artists I like the un-equalized Linear II E.G. I like the tonality of the caparison applehorn guitars played by Mattias Eklundh in his various instrumental/non Instrumental albums because the overall tonality of the guitar is also V shaped, like the Linear II sound signature.
     
    Bass
     
    One of the staunch aspects of this headphone is the bass. If you love bass, this headphone will not disappoint you. It goes very low at different volume levels and you’ll be able to grasp a lot of information you thought never existed in certain tracks. These are power hungry headphones (300 ohms @ 94dB/mW) so if not properly amped, it tends to sound boomy at higher volume levels. Overall a very neutral bass which is very soothing in overall tonality at the same time can be very enjoyable to listen to even for the avid hip-hop/electronic listener.
     
    Bass Extension
     
    Linear II excels in this department more than any closed headphone I’ve heard.  The lowest audible frequencies (20Hz-50Hz) can be heard with grain-less clarity without any straining.  The mid bass tends to sound a bit loose and boomy if not properly amped.  I used to have an issue (when I used DR DAC DX2 as a solo amp/dac combo) in case of particular instruments like the grand piano/player piano in Beethoven, Nancarrow and Webern albums. After pairing Linear II with The EF6 this issue has been resolved. 
     
    Bass Impact
     
    Compared to the modern top of the line dynamic drivers out there the Linear II is not as punchy. Although, it has the capability of producing visceral impact when called upon. After listening to isolated drum tracks this becomes more apparent. Proper amplification is the key here as well, as you feel more air in the bass impact along with a feel of the player hitting(playing) the instrument using a certain amount of strength with a particular tool.
     
     
    2.jpg
     
     
    Mids
     
    This is where the weakness lies. Linear II has a V shaped sound signature which becomes apparent when you listen to non-colored tracks without any EQ adjustment.  This might not be everyone’s cup of tea but there are people out there who might like/dislike this sound signature. LP recordings from the 50-60s era seem to suggest this more often compared to digital media formats.
     
    Without proper amplification and source the Linear II s mid-range sounds very thin and laid back. The mid-range has a slight dip in the frequency response due to the diffuse field equalization. This is an alternative to free field equalization, developed in the 80s to produce loud speaker signals in headphones. This technology reproduces a flat frequency response in the diffuse sound field of the reverberation chamber when sound waves from all direction hit the transducer.  This creates an advantage for the bass and treble as they become more transparent giving Linear II a very edgy sound with a little bit of warmth at the upper bass region. The overall tonality does not suffer due to the laid back mids as both the treble & bass are tuned to be neutral which gives Linear II a very balanced sound. Although it would be incorrect not to say that more attention gets drawn towards the highs and the lows.
     
    Linear II un-equalized has a very edgy sound to it, which I personally enjoy, although I prefer it equalized in tracks where the mid-range is the real meat of the song. If you take music where use of an electric guitar is of utmost significance, the Linear II can do wonders if properly utilized.  E.G Frank Zappa used Gibson SG, Gibson Les Paul and Yellow Strat (All Customized) during the years he was playing a lot of solo guitar improvisations on stage, now why are these guitars important. Frank had a honky and edgy mid-range tonality in his guitars which sounds stupendous when paired with the (EQ Adj) Linear II. Same goes for Guthrie Govan records.
     
    Highs
     
    Linear II shines in this area. Even when the equalizer is adjusted, I do not need to touch the higher frequency spectrum from 4 KHz onwards as they are very soothing at default tuning settings.  In tracks with multiple arrangements being played on top of each other, the instruments which capture the space in the higher frequency register tend to be very detailed and transparent even when a lot of chaos is going on. In various pieces by Varese, Penderecki and Stravinsky this can be observed. Linear II challenges a lot of top of the line dynamic headphones today be it open or closed in the higher frequencies. In fact I prefer Linear II in the highs compared to the T1s, which is saying something. Linear II manages to be soothing and non-harsh even after having a less significant mid-range and impressive bass.
     
    Imaging
     
    In comparison to the modern day flagship dynamic drivers the Linear II is not far behind when it comes to imaging. When it comes down to listening band performances consisting of 3-9 pieces, it is easy to make out which player/instrument is where and the space they occupy to play. Easiest way to confirm this accurately is to have the video performance of the audio source you have. I’ve confirmed this with at least 20 gigs where there are documented audio (CD) and video (DVD) source. What fascinates me about the Linear II is that when I listen to intricate arrangements by Varese, where 13 percussion instruments are being played at various volume levels, with different tonality and frequency parameters, they convey them with stunning accuracy every time with different media formats, even when I’ve used a 1950s EMS401 LP. Linear II is a genre master headphone in the imaging aspect as no-matter what is thrown at it whether it is a 120+ piece orchestra, or a metal fusion instrumental trio or a jazz big band; it always shows an accurate picture.
     
    Soundstage
     
    Linear II definitely has some similarity in sound signature with the Sennheiser family of headphones with laid back mids like the HD25, but it’s a completely different ballgame when it comes down to soundstage considering this is a closed circumaural headphone. For a closed headphone this is something which enthralled me when I first heard it and it still does, to this date. Massive sound stage for a closed headphone.
     
    I had done an A-B test with both my high-end headphones T1 and HE5. The Linear II did phenomenally well, and exceeded my initial expectation. The sound stage is not as big as either due to its construction but they come pretty close. In-fact in some tracks the soundstage sounded pretty much similar to the T1s which is really something. The Linear II driver is well capable of rendering a hollow soundstage like many other modern day headphones. The only thing lacking here is that it does not have the angular positioned drivers like many of the top of the line headphones being manufactured today. (e.g. HD800, T1, LCD2/3) If Sennheiser could release the same headphones today with an angular drivers there will be a genuine interest amongst headphone enthusiasts.
     
    Detail
     
    Linear II has a very detailed presentation when it comes to both bad and audiophile recordings. It reveals the different layers in a recording with precision when fed by a powerful amplifier and source. I have tried it with both balanced and single ended wire and in case of portable use the difference was more apparent as the balanced wire iBasso Pb2 combo delivered lighting fast details for a portable rig. Yet to try a balanced wire with the HiFiMAN EF6, although the default wire set-up gets sufficient amount of voltage into these cans.  With the Linear II I’ve rediscovered a lot of tracks which I was very familiar with but was unable to grasp all the minute details, instruments, several layers of rhythm within rhythm and harmony created out of rhythm. These details were re-discovered in most of Frank Zappa’s synclavier compositions spanning over a couple of albums.
     
    Portability
     
    This headphone can be used for various applications from home/office use to portable. I personally felt that Linear II needs a lot of power to be driven by a portable device.  Amplification helps a lot to make the Linear II sound a lot louder. I bought the iBasso Pb2 amp along with HD650 balanced wires for this purpose and they had an incredible synergy. I have used a lot of portable headphones/IEMs for the last 8 years and to me this was the best portable rig I have ever used period. This combo enabled me to carry about 60% of the fully optimized Linear II sound on the go, which was a very engaging experience. The only issue which rose was managing the wire with a couple of silicon bands as the wire itself was very long. Proper arrangement of the wire is a must whenever someone is carrying a headphone with heavy, thick and lengthy wires.
     
    Isolation
     
    Linear II is a closed circumaural headphone meant for private listening. It does a pretty good job of isolating the listener from the surrounding ambient noise. One can only hear outside noises/sound if the headphone is being heard at very low volume levels. Even in case of portable use this headphone does a pretty good job of isolation. At mid-high volume levels it is very difficult to hear any outside noise if properly amplified. The headphone does a robust job when it comes to blocking leakage as well, as it does not attract unnecessary attention of the surrounding individuals. 
     
     
    1.jpg
     
     
     
     
    Amplification
     
    This headphone has an aluminum voice coil which needs a fair amount of electricity to drive them at decent volume levels. A headphone amp is a must for the Linear II as it has an impedance of 300 Ohms @ 94dB (sensitivity/1kHz). Linear II is not the most efficient headphone out there but as far as the modern day high end dynamic drivers go, they are not as demanding when it comes to electricity. Compared to the T1 (Now sold), HE5, K340, 141 they can be driven easily at lower voltages. I personally feel that the Linear II needs an airy, warm, powerful amp to sound at its peak. When I got my first Linear II (Ireland), I paired it with DR DAC DX2, and I was completely floored by the sound. This was a time when I was listening to the T1 and HE5 for several months. I immediately conducted an A-B test with the T1 which lasted for a couple of days and the Linear II was able to match it almost in every department.
     
    After few months passed the Linear II sound got settled in my system and I was able to find out the few deficiencies the Linear II had compared to the T1. But there were very few. My perception about high end Sennheiser headphones changed again as I was not very satisfied with the previous full sized Sennheiser purchase/loaners (HD595/600/650). Presently I am using the Linear II with the HiFiMAN EF6 (as amp) along with the DR DAC DX2 (as DAC). The headphones have really opened up and sound marvelous. While listening to studio recordings you get a real feel of what is going on, how the tracks have been mixed, even In songs where I used to hear four themes going on simultaneously without paying much attention, now I can even hear more instruments being added to mix with the recurring theme and I am also able to recognize when that instrument is being introduced to the mix without concentrating too much. In case of live gigs the instruments sound very much like you are sitting in the front row, with all the extra dBs being thrown at you from the monitors.  The EF6 does not go over 10 O’ clock even in low volume Webern recordings. 9 O’ clock for the DR DAC DX2. I use the ‘winamp’ player for audio listening and ‘VLC’/’WMP’ (K-Lite Codec) for video. As far I am concerned the Linear II, EF6 combo is very enjoyable to listen to for brief/prolonged period of time.
     
    As mentioned earlier I have only been able to use the Linear II with the iBasso Pb2 Pelican amp, as it was the only portable amp powerful enough to drive them at loud volume levels. Powering the Linear II via the HD650 balanced wire was really an enjoyable experience. Most of my music listening takes place while I am mobile and I have listened to a lot of portable rigs in the last 8 years, and by far the Linear II, Pb2 combo is the best I’ve heard. Will be trying a DAC+AMP combo in the coming years to see whether it has any effect on the overall presentation.
     
     
    Linear II Germany vs. Linear II Ireland 
     
    Design
     
    Both headphones are all black, similar shape and construction in every section except the outer ring of the headphone which holds the ear pads. The outer ring of the German version is made of metal whereas the Ireland version is made of ash colored plastic. In the German version one side of the headphone adjuster says “Made in Germany” while the opposite side says “Made in Ireland”, whereas in the Ireland version it is written Made in Ireland” on both sides. Why is it like this? I do not know. If anyone has an answer, please solve my query.
               
     
    5.jpg 4.jpg
     
     
     
     
     
    Sound
     
    Interestingly enough, both the headphones do not have the exact sound signature. The German version has a fuller mid-range compared to the Ireland version.  Linear II in general has a huge sound stage, although the German version is a bit wider. More or less they are the same and require same amount of power to run them.
     
     
    Equipment
     
    Widows PC with a Creative Audigy sound card
    MacBook Pro
    Colorfly Music Tablet CT971
    Crosely CR083 Stac ‘O’ Matic Turntable
    Various Android & iOS based devices
    DR DAC DX 2 DAC/Amp
    HiFiMAN EF6 Headphone Amplifier
    iBasso Pb2 Pelican Balanced Portable Amp              
    Taket BPP
                            
     
    6.jpg
     
    CONCLUSION
     
                              PROS                                                     CONS
    1. Diffuse Field Loudness Equalization
    1. Not as lush and liquid in rendering compared to modern day drivers
    1. Quality Bass Rendering
    1. Bass not as punchy as present day closed headphones
    1. Powerful Bass Impact
    1. Laid Back Mid-Range
    1. Deep Bass Extension
    1. Needs a punchy, warm, airy amp with lots of Power
    1. Accurate Imaging
    1. Discontinued
    1. Big Soundstage
    1. V Shaped Sound Signature
    1. V Shaped Sound Signature
    1. Availability of Spare Parts
    1. Portable
     
    1. Detail Revealer
     
    1. Genre Master
     
    1. Transparent Sound
     
    1. Isolation
     
    1. Precise Instrument Separation
     
    1. Huge Choice of After Market Cables
     

    Nord, eugenius, padam and 1 other person like this.
  2. padam
    5.0/5,
    "An overlooked closed headphone"
    Pros - excellent treble and bass extension, soundstage, durability, comfort, isolation, suitable for lower level listening
    Cons - discontinued and hard to find, midrange is a little thin and bass can be a little overpowering
    Revised 2011/06
     
    These were studio monitors made between 1991-1995 and 2000-2007 (wonder if they brought them back on request). Some changes were made during production so not all pairs sound quite the same and they didn't apply HD600 levels of quality control either, which means that in some pairs the drivers might not be as closely matched as with others.
     
    Let's being with the most surprising aspect, which is the bass. Amazing punch, depth and extension when the recording demands it, but with much less colouration and muddiness that is presented in most closed headphones. It extends a bit below 20 Hz with a good amp (some amps to roll-off earlier). It simply redefines bass extension as there are not many headphones out there that can go really low. The O2 also has good bass extension but being a fully-open electrostatic phone, the presentation is different. If you want a more punchy bass you might prefer the bass of these in some ways and but you probably want it with the texture of an O2 as well (which you obviously won't get).
    On the downside, the bass can be overpowering and a little slow at times and slightly muddying up the sound (but it also depends on how the system is tuned and I think I managed to balance it out). It is great for rock pop and electronic music or any kind recording which is bass-shy (or the opposite, driven by the bass) but not ideal for smoother music.
     
    The highs are also excellent, weighty and extended and just in the right quantity with none of the veil you might feel with the HD6xx series. If you pair them with a bright (or low-end) source they might show too much of the flaws present in some recordings (or the source itself) but with the current setup I have no complaints, they are excellent.
     
    The midrange is ok. It is slightly on the thin side but at least free from peaks (but there is a dip somewhere, see diffuse EQ later). Being a studio monitor the focus will always be more on the analytical side than on the musical side but the whole sound will always depend on the system, not just the phones themselves and they are definitely not boring or lifeless.

    I also use the original HD 250 Linear headphones (which are over 20 years old, both 300 ohm and 600 ohm variants exist) where the drivers are incapable of providing the extension of the Linear IIs so they sound brighter. The mids are slighty purer because there is less bass but overall I prefer the IIs. Other interesting relative is the HD 540 Reference II which looks remarkably similar but with an fully-open housing so people who think the HD 250 Linear II is nice but has a bit too much bass would probably find these more balanced although not as extended.
     
    So basically what we have here is a very balanced, dynamic (energetic), analytical type of sound with good transient speed and detail and great clarity (for a dynamic phone). It is also very extended (full-range) on both ways and free from any big peaks and with a slight dip in the midrange (diffuse field EQ?) and a rather strong bass response. With this type of FR the sweet spot is lower than the average headphones, so it is great for low level listening as well.
     
    The soundstage is also very good, especially for a closed phone and better than many mediocre semi-open phone as well. In the brochure I read that Sennheiser applied diffuse field equalization and it seems to work well here.
    While it not the widest it is not cramped like most supra-aural phones and has good depth and imaging. Of course a good open headphone will always sound more natural but really you can't expect much more from a closed one.
     
    The comfort is great. Snug (circumaural) fit with very little clamp and they are quite light for their size, they almost disappear. The pleather pads can be a little sweaty at times. The headband adjustment is easy and simple. If it is a bit loose (like on my original Linear) it is recommended to tighten up a little for the best sound. The isolation is also quite good, although it not quite as good as the HD25s but better than the Audio-Technica ESW10JPN and vastly better than the Sony CD3000 or Denon D2000.
     
    You can certainly tell that these were made for the studio as they are very durable and rigid. I have a pair which is 20 years old and with new pads and foam it sounds just as good as new (but these are essential for the best low-end performance and to calm down the highs a bit). Despite being made from cheap materials, the construction is very sturdy. That said the voice coil (internal tiny wires between the drivers and cable connectors) can be a little vulnerable and repairing that is really hard so it's better not to drop them. The cable is easy to replace. The connector type is the same as with HD6xx series. So it is possible to experiment with various expensive aftermarket cables - if you think that these are worth spending for as opposed to a better source/amp... Putting on a HD650 cable might worth a try as well, it is very cheap but the stock cable does seem to have a sound signature suited to the phones so some people claim it is best to leave it as it is.
     
    Movies or gaming? They handle them very well because of the soundstage and bass extension (and comfort) are still very much useful here. But these don't work well with Dolby Headphone because they are already diffuse-field equalized.
     
    All in all, I think these are great headphones (but I wouldn't go as far as all-rounders) and since I have these I have reduced my collection quite a bit.
     
    No, these are a long way from being one of the best headphones of the world. However, if we add the tags like 'closed' and 'dynamic' or 'isolating' I would say they are certainly up there.  They are simply brilliant for what they are and the fact that Sennheiser is probably not going to bring them back again and just continue with what they are doing now makes me quite sad. I think if they would improve the construction slightly (e.g. improve the drivers and protect the voice coil, aluminium housing for better resonance control, nicer-looking headband) and re-position them in the market as high-end closed, consumer headphones they would be more than competitive today.
     
    Despite being a rather important part of the current market they don't have anything here, so I hope that will change in the future.

    Tus-Chan likes this.