Electronics : Sennheiser HD650 Reference Headphone

Rating: - Audiophile sound
Contrary to a couple of other reviewers who have stated that these will not sound good without a quality headphone amplifier - balderdash! I own a quality headphone amplifier, and whilst this doubtlessly improves things (as one would expect) the HD650s still sound excellent when plugged directly into my CD player or even my Hi-MD walkman, no problems driving them at all. And the supplied literature backs this up, stating that they can be 'directly connected to stationary hi-fi components of the highest quality' - well, admittedly, whilst mine are good they are not the HIGHEST quality, but nevertheless, these phones have no trouble delivering. But, yes, a dedicated headphone amp does take things to the top level.

And the sound - it is close to perfect. The bass is completely realistic and well extended, rather than overblown or muddy as is the case with many cheaper phones. The high frequencies are naturally airey and clear, making for relaxed listening without the need to push the levels too hard (unless you really want to of course).
The mid range is sounding very clear and undistorted. These cans have only been out of the box for an hour, and they have a recommended run-in time of at least one or two days constant useage, so I only expect this already wonderful sound to improve further still.

Comfort is not a major issue. The earcushion on each of the cans fits very nicely around each ear with room to spare (for my 35-year-old ears anyway). The pressure is, however, just a tad too tight on the sides of the skull (but I can cope - and maybe they are expected to loosen with age). The literature also states that the pads should be replaced periodically for hygenic reasons, but I can't work out how these are detached since they appear to be stuck very securely in place. I've already tried pulling as hard as I dare without the risk of ripping them. So I don't get it.

Anyway, the earcushions (in theory), along with the 3 meter cable (which does detach easily enough from each of the cans) are replaceable, to extend the life of the product.
And it all comes in a hard box with a hinged lid.

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Rating: - Sennheiser HD 650: does it provide marginally or greatly improved sound when compared to the HD-600?

The HD 650 is a true audiophile-quality stereo headphone superseding the previous HD 600 model. It connects directly to most audio devices accepting a 6,3/3,5 mm jack plug.

Sound quality is achieved by the use of well damped, extremely lightweight but powerful aluminium voice coils ensuring excellent transient response and clear, transparent and balanced sound. The bass goes down to a very satisfying 40 Hz.

The HD 650 uses the "diffuse-field" loudness equalization principle (as opposed to the "free-field" equalization type) to attempt to "flatten" the perceived frequency response. Diffuse-field EQ assumes that the listener is in front of a sound source in a listening room with reflecting walls. Because diffuse-field EQ is based on an "average" head/ear shape and room model, it may not appeal to all listeners or sound "natural" with all recordings. Personally, I have yet to find a better type of headphone system (given the fact that I listen in a quiet environment.)

The circumaural design - featuring ring pads that surround the ears - and the velveteen "breathing" fabric covering the ear pads are very comfortable (even over extended listening sessions.)

I have used Sennheiser models since 1975, beginning with the Sennheiser 424 at the beginning of the seventies, "upgrading" to Stax electrets headphones in 1980. I returned to Sennheiser for its HD 565 Ovation model in 1985 and bought HD 600 earspeakers in 2004.

An audiophile friend did lend me his HD 650 to let me audition them for a while and they sure sound pretty impressive, displaying more nuance than the HD 600. However, the results are not significantly better to me than the ones I am already enjoying from my HD 600. For this reason, I have decided not to splash money on them. Should you buy a new high-resolution headphone set right now, I would although advise you to go for the HD 650.

Now, I am quite happy to learn that many people enjoy using the HD 650 even when associated with "average" sources and assorted electronics.

However, you should be aware that you would not be able to enjoy the HD 650 (or HD 600) to the full unless you also use true audiophile grade associated gear.

Also, do not forget that headphones present an unusual acoustic environment in which human ears were not designed to operate. This said, to be musically valid, the experience of listening to headphones does not have to be identical to that of listening to one's main system any more than listening to one's stereo need be identical to the real event. You do give up some attractive imaging information when listening to even a top headset. Ambience suffers as well. What you gain is immediacy, a sense of proximity to the music that has its very own appeal.

For about one year now, I have been running my HD 600 from the US HeadRoom Desktop headphone amp, which replaced my trusty Musical Fidelity X-Max (v1.) The former amp uses a patented, truly innovative discrete crossfeed circuit that "bleeds" a measured amount of opposite-channel information into each stereo channel, in order to cure the hard-left/hard-right image location common to 'phones listening (although, in all fairness, the X-Max was already quite enjoyable.) By adding time delay, the amp also compensates for Inter-Aural Time Difference (ITD), which is one of the ways the brain establishes the location of sounds. The net result of this blending of sounds and timing is an image that does not inhabit the head, but rather seems to be located more in front of the listener, spread laterally across a wide soundstage (this amp is, alas, available only by mail order from the manufacturer at a price of around £ 360.) I have simply connected my HeadRoom amplifier to a line level output from my Linn system (featuring a Linn Ikemi CD player, and Linn Majik pre- and power- amps.)

Unless you plan to use your HD 650 headphones on the move (?), the use of a separate headphone amplifier seems to me mandatory. If money is a concern, you could however assemble a very satisfying headphone system by partnering a second-hand Sennheiser (i.e. HD 565 Ovation or HD-580) with a used Musical Fidelity X-Cans (v1) tube headphone amp for a very reasonable price.

Now dig all those crazy details buried in your favourite recordings!

P.S.: For those enthusiasts who would like to compare the technical performances of various quality headphones (regarding frequency response, harmonic distortion, isolation and impedance), I recommend to check out the headphone.com website which enables you to compare up to four different types of quality headphones.

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Rating: - Sennheiser HD 650s - the best!
I do not intend to get technical, but will simply focus on my experience of using these headphones over the past year. I will identify the key weaknesses and assets of these headphones.

The Weaknesses:

1) - At nearly £200 they are considerably more expensive than the average headphones.
2) - Your speakers will probably sound awful when you take your HD650s off.
3) - They are a bit uncomfy (see asset 4).

The Assets:

1) - They come a in fab presentation box which is a good (though unrequired) bonus.
2) - They allow you to hear the most subtle detail - for better or worse.
3) - They sound great with music, TV and film (especially modern programmes and films) and playing games on the PC. For example, Stargate SG1 is amazing - you feel like you are there.
4) - The more you listen to them the comfier they get. I can use them for hours and not really notice that they are there i.e. they become comfortable in time.
5)- They are upgradable via specialised cable such as Cardas.

If you are thinking about buying these, but are not sure, consider the following.

1) - Spending money on these does not mean that you will have no money to buy more cds, currys, clothes or whatever. All the other things you want to buy will be there next month and the month after that and so on.
2) - Your next wage is probably only 4 weeks away at the most. If you've never starved in the past, you probably won't starve if you buy these.
3) - If you buy these you can rest assured that you will not have to buy a new version 6 months from now. As headphones have been around much longer than new technologies such as the mobile phone and mp3 player, headphone technology has already matured past the initial design and redesign stage. Headphone technology is pretty stable and established. Therefore, these headphones can reliably be claimed to be more or less at the pinnacle of headphone technology.
4) - If you buy a punto, you get a punto. If you buy a Daimler, you get a Daimler.

5) - Go and buy them!

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Rating: - Wonderful sound
I have owned a pair of these headphones for almost a year now, and the sound they produce is quite simply divine. The first time I put them on, I felt the pads did press quite hard on my head, considering what I was expecting from reviews. After a little tweaking of the headband, I found them to be more comfortable and once I had been wearing the phones for a couple of days the pads softened. The result was the most comfortable fit I have ever experienced in a pair, and believe me I have worn many a pair of headphones..

I think after stumbling upon the review below, I felt compelled to leave my feedback as I thought the reviewer seemed truly misguided. The sound these headphones produce, while not completely geared towards a completely flat response (as this was the idea of the 600s) is very truthful. You will find that if you have not been subjected to 'proper' sound, for example in a studio environment, you may think that they sound perhaps different to what you would expect. The average person's opinion is perhaps generally that one wants lots of deep bass and high treble to create an 'impressive' sound. While this may impress, at the end of the day one has to fiddle with equalization controls to adjust the sound for different records, as not all of them will sound good. The reason for this would be that the sound the equipment (speakers or headphones) is producing is not a balanced sound. One will probably, for example find that some records appear 'harsh' on the ears when up loud on a lesser system, and this would be the fault of the listening equipment. There are many other factors that would make this review too long, but the general idea is that if you want to hear exactly what the producer created in the studio, then you want something that matches the 'standard' of sound as closely as possible.

I have been producing, recording, editing and listening to music for many years and these headphones represent what I would consider to be some of the best in headphone sound quality. I actually think that I will never want another pair to replace them.

Decent sound comes at a price, as the materials chosen have to be picked and put together extremely accurately so as to perform exactly as required. Creating accurate headphones is an art, and Sennheiser's many years of experience has clearly lead to their producing headphones of such a high quality. To think that a company with such experience in building accurate devices such as these would place a piece of material in their headphones that degraded their sound is completely ridiculous. Do you really think that a company that invests so much money in developing accurate drivers would sully their reputation and bring down the quality of their high end products by not considering such a thing? I think not. The headphones were designed to be used as they are presented, no changing of cables and ripping out of integral parts will make them more accurate, in any case it will probably do the reverse.

On a brand note, I did have the opportunity to experience Some high-end Sony DJ headphones, which did sound quite good until I compared them to the 650s. The immediate thing I noticed as the harshness of the Sony sound. Playing 'Hunter' by Bjork, I found that the vocals became ear piercing on the Sonys, yet remained silky smooth and accurate on the 650s. All the separate sounds in the track remained clear and were never drowned out, a problem I discovered with the Sony earphones.

(if looking for high quality headphones I highly recommend this track for judging the quality of the midrange, (something often overlooked) as the vocals really push the equipment you are listening to to it's limits and at high levels will really sound painful on anything of a lower quality)

The bottom line is, if you are looking for headphones that will impress the un-trained ear, then go for some of a lower calibre. Perhaps consider some sub-£100 Sennheisers, as these are of a pretty high standard and probably will sound better than most of the other 'high-street' brands. If you are, however looking for a pair of headphones that will give you the true sound of your records and will probably make you hate every other piece of sound equipment you have ever listened to, then buy these. The quality is superb for all genres, and until you have sat down and watched a big budget film with an orchestral soundtrack on these cans, you do not know what you are missing.

** You do not need ridiculous hardware to appreciate these headphones. Integrated circuits today are of such a high quality that even cheap amplifiers (as long as they have the EQ turned off) will produce a decent sound. The only thing one has to worry about is how powerful the amp is. I found that my friend's iPod for example did not really have enough 'kick' to turn these up loud. Not all portable devices have the same output power and I am sure to some 'audiophile' reader's disgust I should point out that I had the opportunity to try the 650's on a sub £10 CD player, and they sounded just as good as they did when plugged into my hi-fi. A lot of this expensive CD player business is just a great big con!

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Rating: - Initially disappointing
After using a pair of thirty pound sony MDR-Q55 walkman headphones for a couple of years I decided to splash out on a pair of expensive headphones. After reading all the reviews and recommendations I plumped for the Sennheiser HD650's.

I've just taken them out of the box, listened to a couple of songs, and what can I say!!

Utterly disappointing!!

In fact, my very first impression was that my MDR-Q55's sounded BETTER - less muffled and with better stereo seperation. However, it's not that the Sennheiser's are more muffled, it's just that they are more refined, taking a lot of the 'punch' out of music, and I find this a little disconcerting, as I like rock music.

One area where the Sennheisers are a noticable improvement over the Sony's is in the area of distortion, they seem to be able to take higher levels of volume without becoming uncomfortable to listen to.

Overall I am disappointed with these headphones. The sound quality is just not what I was expecting for near two hundred quid headphones. Maybe I had too high expectations for 'reference' headphones, maybe I need to give them a chance to run in a bit. Possibly. But right now, I am firmly determined to send these things back and get a refund.

...this is an update to the review above. Since posting the above review I've did some further research on these headphones.

First off, the system I listened to these headphones on was a high end laptop running MP3 recordings (at 192kbs). I've since learned that `compressed' digital audio does not allow these headphones to shine. Also, the 300 ohms impedance of the headphones is unsuitable for portable devices such as laptops, ipods, and portable MP3 players without a headphone boosting amplifier, something which will add another 100 quid or more to the package. Portable amps (like the Portaphile V2.2) are available.

Another common issue with these headphones is that right out of the box they can sound `veiled', which is something I commented on in the review above, and need around a hundred hours burn in period to `open up'. It is also recommended you remove the foam strip which covers each speaker (which is easy to do), as this has been partly blamed for the `muffled' or veiled effect.

As I stated in the review above I was determined to send these things back but now I think I will stick with them. Even plugged directly into my laptop they 'do' offer better sound quality than my Sony MDR-Q55's (especially in bass) but just not at the level I was expecting, but my laptop probably can't provide the power these headphones need to operate at full proficency.

I've decided to stick with them (partly in case I get a more advanced sound system in the future) and have also invested in the Portaphile 2.2 'maxed' headphone amp (140 quid) and the (recommended) Equinox cable (120 quid) to replace the (much criticized) one that comes with the Sennheisers.

If you are intending to use these headphones with cheap or portable equipment I would recommend you listen to them before buying (with the recommended 100 hours burn in period) as you may be disappointed with the sound quality cheap equipment provides with these phones, or be prepared to shell out further money on a decent headphone amp.