The Buying Experience: The stunning sound quality produced by FiiO X3, a portable digital music player. purchased in March 2014, prompted a hunt for a decent headphone to come up to par with the unit's performance levels. Sennheiser PX 100 Mk II, a folding travel type(MRP? 4.4K) that I was using then(and still do sometimes during travels for mp.3 music from my mobile phone) is not a bad performer, but I felt that the FiiO unit clearly needed something better because of its capability to playback higher resolution tracks like FLAC and WAV files. I also gave my older Sennheiser HD 320(from early 90's around GBP 40) at try. I felt it was a tad laid back, compared to the somewhat bass heavy and less refined PX 100 II. I always preferred open-back headphones to closed types, whether they are circumaural(surrounds your ear) or supra-aural(rest on your ear). I am not one bit comfortable with ear buds or plugs that are inserted into the ear canal.
The cost was not as much a constraint as striking a balance between cost and performance. With Sennheiser, at entry level to their high end HD 5-series, there were three, HD 518, HD 558 and HD 598(MRP? 10K, 15K and 18K respectively) and at a higher level and much higher cost, there were HD 600 and HD 650(MRP? 32K and 34K) that wanted to consider. Unfortunately, the 6-series had to be ruled out from just reading specification sheets(though the sound was a lot more refined and resolving than any in the 5-series when I heard a HD 600 at a demo). The HD 6-series were rated at 300 Ohms, whereas, the HD 5-series work on 50 Ohms loading. The FiiO X3, as a stand-alone unit, can only handle higher efficiency headphones with impedance rating of 70 Ohms and below. If I had to buy one of the 6-series, then I would have had the need to add a portable amp to hook up to the FiiO X3 to get the best out of the HD 600 or HD 650 - to me that is excess baggage. Months later, I proved that eliminating the 6-series was right thing to do when I plugged my cousin's HD 600(which he uses with a X5 player which can handle high impedance headphones) into the FiiO X3. It sounded far-away and not cohesive, probably due phase shift caused by higher power demand at certain bandwidth, and I can't be sure.
Though I have mostly used Sennheiser headphones in the past, I am not a one-brand aficionado. At the time of purchase of the FiiO X3, the seller had recommended Audio Technica ATH-AD900X(MRP? 17K), Sennheiser HD 598, Ultrasone HFI-2400(MRP? 20K) and a Beyer Dynamic model I can't recall. I was not able to audition makes other than Sennheiser here in Chennai.
With Sennheiser HD 5-series, all three of them were very comfortable to wear even the first time around, and were also fairly close to each other in terms of sound quality, I did not care much for the colour and aesthetics of the HD 598(cream/burgundy with faux-wood trim). The HD 518, in comparison to HD 558, looked a little flashy and dated, and to me, it also sounded marginally bass heavy with a sound stage was not as wide as the 558 or 598. The HD 558 sounded just right to me, wide open sound stage but somewhat receded, bright clean highs, clear transparent well layered mids, perhaps a tad low on the bass front. I didn't really mind that. Between the HD 558 and HD 598, I could not make out much difference in the sound quality, Perhaps the bass on HD 598 sounded marginally forward and tighter, at least that is what I thought during the hour long demo period(which was in a somewhat noisy showroom environment to audition open-back headphones). And as for the looks, HD 558 was my winner for its staid, minimal chrome effects, matte-black looks - as Teutonic as anything from Germany could possibly be, except for an anti-climax fact that they are all made in China.
The Design and Construction: The HD 558 is all plastic, except that it is not cheap plastic that one conjures up in the mind at the mention of the word'plastic'. There are no signs of'flash' anywhere, something that is normally associated with injection molded plastic. The build quality is solid, well, almost good to take on a Made in Germany tag. The plush velour ear pads and headband cushion are soft and conforms to the user's head profile quickly. The adjustable slider headband, along with slightly pivoting driver housing, inserts the right amount of side pressure to hold the speakers perfectly in place around the ears of most head-sizes - absolute comfy for hours on end. At 260 grams, it is lightweight for a full-size headphone, and the fit and comfort actually makes it feel much lighter than what it is.
The head phone cable is detachable from headphone, which is a good thing. The supplied 3 meter tangle-free stereo cable is connected to the bottom of the left head-shell via a 4-way 2.5mm twist-lock jack. At other end of the cable is a regular full-size 6.3 mm 3-way stereo audio jack. A rather robust looking adapter, 6.3 mm to 3.5mm mini-jack, is also supplied for use with portable devices and mobile phones. Plugged into my FiiO X3, this 6.3 to 3.5 adapter looks like giant silencer fitted to a James Bond sub-compact Beretta pocket pistol. ugly! Not to fret, Sennheiser does sell a shorter 1.2 meter accessory cable(HD 5x8) with 3.5 mm mini-jack which removes the ugly adapter from the equation, and at the same time, offers a more manageable cable length for use with portables. I do wonder, why a 4-way jack at the headphone-end and a standard stereo 3-way jack at the player end. The only thing I could come up with is, that at one stage, the design team had thoughts about adding a volume/tone/mute contraption to the cable. Thankfully, they didn't do that because I know from past that such controls tend to degrade the otherwise clean signal path.
The Sound: As I had mentioned earlier, the sound quality, with any type of music, is simply hard to fault. With a stated frequency response of 15 to 28000 Hz and SPL level of 112 dB(at 1KHz/1Vrms) it is not going to miss out on anything that is being fed and at high volume levels. Purely from the lab point of view, my frequency response test shows a marginal drop-off of around 6dB at 90Hz, which means there is going to a slight drop in the deep end of bass. There is a small boost of 3db around 120Hz which means that mid-bass(a range that we mostly like for its tight kick at the bass end) would be on the plus side. As for the rest of the frequency range, it is pretty flat right up to 12KHz where there is again a steeper drop-off by 12dB before it climbs back to zero(normal) at around 17KHz, and this means lower treble(like sibilance in vocals) is going to be subdued, while the extreme treble end is still going to shimmer and sparkle. So much for tech. talk.
In reality, this headphone is slightly laid back with almost an enduring valve-like quality that many will like. I say valve-like because I still use vinyl LP records played over an Audio-Research valve pre-amp and a Krell Class A power amp for home audio. The HD 558 lacks the slam-bam dynamics of the home audio, but it has all the essence of engaging warmth and neutrality one could hope for when looking forward to listening to long hours of non-fatiguing music. The sound stage is wide and well defined, perhaps a bit recessed, vocals are pristine and detailed, cymbals sparkle, bass is tight and packs a woof, deep bass is not as thunderous as should be.
TheTracks: from albums used for evaluation:
Berlioz - "Sinfonia Fantastica" - Kojian with Utah Symphony Orchestra(Reference Recordings RR-11) - for pipe organ bass and choir vocals.
Bach & Brochini - "Simply Baroque" - Yo-Yo Ma -with Koopman and Amsterdam Baroque Orchestra(Sony Music #60680) - for timbral balance.
The Astounding Eyes of Rita - Anouar Brahem(ECM #1798628) - for bass clarinet response.
Brothers in Arms - Dire Straits(Vertigo #8244995) - for dynamics and clarity at studio recording.
Jazz at the Pawn Shop Vol. I & II - Arne Domnérus et.all(First Impression Music #FIM-12) - for ambiance of live recording.
New Moon Daughter - Cassandra Wilson(Blue Note #CDP 8371832) - for female vocals and band dynamics.
Blues Union - Joe Beard(AudioQuest - JVC XRCD #25) - for male vocals, electric bass and drums.
Babylon by Bus - Bob Marley & the Wailers(Tuff Gong Re-mastered #TGDCD 1) - for bass response at live concert.
Rich Woman(from Raising Sand) - Alison Krauss & Robert Plant(HDTracks FLAC 96/24 Download) - for industrial rock/pop.
. and there could have been more.
For Whom?: Anyone who take their music listening seriously and for hours on end. I would be hard pressed to match suitability by genre of music, but I feel that die-hard bass-freaks will find better options elsewhere. It is also not well suited for those who listen to music on the commute. The open back design will allow you to listen to everything that is going on around you, though disturbing others through music leaking from your headphone is not a cause for alarm. It does leak sound, but not as much as I thought it would.
A Bad Apple Story: I got my HD 558 in Sept 2014 from a local dealer(at? 11.5K). All was fine until late Dec, when the right channel went dead. It was probably a soldering joint that had come loose, something that I could have easily fixed myself(yes, I do have silver solder and soldering iron, and I also have a habit of tweaking audio components). However I wanted to see how Sennheiser India would respond. For 10 days after my complaint, nothing happened. The Head of India was brought into the picture. Then I was asked to take the defective unit to the distributor in Chennai(who I assumed would have the required facilities to solder a disconnected wire). The distributor was nothing more than an electronics and white-goods warehouse. But they took the unit to be dispatched to Bangalore for inspection and repair. A few days later I got a confirmation that my unit was indeed defective and that it will be replaced by a new one. When I asked for the original unit to be fixed and returned, it was refused point-blank that it was'company policy' to replace with a new one. A week went by, and I received a replacement unit. This unit looked like it was used, with water marks on the ear-cushions and scratches on the headband plastic. Even the packing case looked like it was pulled out from under some rubble. In terms of sound, it did not sound as smooth or as clean as my first unit(that was expected because the first unit had already gone through some 200-odd hours of use and was probably fully'burnt-in').
I wrote again to Sennheiser India, stating that I was not happy with the replacement. I also mentioned that the difference between the serial numbers of the replacement and my defective unit were too wide apart, mine being later off the production line. After several argumentative email exchanges, Sennheiser India was neither going to repair and return the original unit, nor send another replacement - and that's that.
I wrote to Daniel Sennheiser, CEO of Sennheiser International at Germany, stating the entire story. Within three days, I received another new unit, this time delivered to my house by none other than the Head of South India operations based in Bangalore - he had driven from Bangalore to Chennai just to do this. The second replacement was new indeed, both, by looks and serial number. Altogether, I was 558-less for close to a month, but the morale behind the story is that Sennheiser do listen and attend to their customers' needs. Not only that, from my past experience, they are also able to supply parts for out of production headphones that were purchased in the 80's and 90's(headband and ear pads for my HD 320, ear pads for my HD 414 which is ancient and not with me anymore). The defect with the HD 558 has to be written off as a rare one-off incident, nothing more.
Verdit: One thing I learnt from this replacement experience is, that out of the box, the HD 558 may sound a little congested and less refined than a unit that has gone through a burn-in period of, say, 150 to 200 hours. First time buyers may not be aware of this fact and will probably accept the out-of-the-box sound to be real sound they expect to hear for the rest of units life. That is far from the truth, as it is played on, the sound improves, the stage widens, the separation between instruments increases, vocals are clearer, bass response is much tighter and deeper, and so on and so forth - something like a good thing just got better. Today, the second replacement, after 3 months of everyday use, is very refined and smooth sounding than when it was new.
Is there a better sounding headphone than HD 558 for the same amount of money? Probably, yes. Would I recommend the HD 558? Without doubt, yes. However, one keep in mind that HD 558 deserves a quality audio source to bring the best out of it. Would I go for another Sennheiser headphone again? Yes, and it will probably be HD 600.
