From well-behaved to fire-breathing: the Sennheiser PXC 550 tested

As befits a musical travelling companion, the PXC 550 Wireless, which sells for a proud but not outrageous price of 370 francs, has the following advantages: high wearing comfort, lightweight, closed design including NoiseGard noise killer, foldable design, 30 hours of playtime on a single charge, high speech intelligibility during phone calls, TalkThrough function, touch-sensitive trackpad with a surprising number of functions, energy-efficient 4.2 Bluetooth standard, paired with aptX and NFC. Last but not least, this handset comes with the Captune app with a wealth of options.

Perfect shapes

Sennheiser measured hundreds of ears to find the perfect shape for the shells. Thanks to high-quality hinges, the headphones can be elegantly folded and stored in the case to save space. The handset is switched on and off by turning the right-hand shell. A voice announces the processes taking place.

Only two visible buttons are used to select the effect modes and the NoiseGard. The trackpad on the right earpiece has a lot to offer and provides a large number of functions. Swipe up and down to adjust the volume, swipe forwards or backwards to select the previous or next track. Pressing and holding several times controls other functions, particularly those relating to making calls. As with the Momentum Wireless, it is therefore important to study the operating instructions, as you can hardly get any further here just by fiddling around.

The Sennheiser people have also invested a lot in this headset to ensure the best speech intelligibility. VoiceMax technology utilises no fewer than three microphones: one microphone picks up the voice, while the other two register signals to suppress background noise.

Versatile app

The Captune app alone would be worth testing in detail and not only offers a player that has access to the entire music collection of the smartphone, it also supports Tidal's music streaming service and allows you to listen to music collections via DLNA for Android or Airplay.

The Captune app is a great element in the element.

The app is very much in its element when it comes to sound tuning. There is a freely selectable equaliser with which practically all sound patterns can be set and also fixed. Not only the frequency response, i.e. bass, mid-range and treble, can be selected according to your own sound preferences, but also the spatial conditions in the "Director" sound programme. Captune also supports music formats such as MP3, AAC, FLAC, OGG and WAV. The iOS version plays MP3, AIFF, AAC, WAV and Apple Lossless (ALAC) formats. The strength of the NoiseGard can also be selected.

Dosable noise killer

Noise cancellers, also known as NoiseGard or noise cancelling, all work according to the same principle: the noise entering the earpiece is accompanied by the same noise, but with reversed polarity, in the hope that the two signals cancel each other out. The noise killer, which Sennheiser calls "adaptive noise cancellation NoiseGard Hybrid", is designed to adapt to the type of ambient noise and thus cancel it out even more efficiently. No fewer than four microphones are used for this purpose.

The fact that such noise killers do not work without collateral damage is not just an assumption, but a fact. There are sensitive people who feel a certain pressure in their ears when the noise cancelling is switched on or feel uncomfortable in some way. The NoiseGard has been created for these people with a selectable level of use. Depending on the switch position, the listener can choose whether NoiseGard should always be fully active or whether it should be used in doses. The user thus determines how strongly NoiseGard should intervene and can minimise any audible interference.

The NoiseGard delivered excellent results in practice and enables (almost) undisturbed listening to music even in relatively noisy environments. Low-frequency noise, such as the humming of the neighbour's lawnmower, is almost completely blocked out and only higher levels of interference such as police sirens, the hissing of loud voices or the hissing of tyres on wet roads can slightly spoil the listening experience. No headphones with noise cancelling can achieve total silence in a noisy environment. However, the dampening effect is very considerable.

Measurements

The measurements clearly show that these headphones will sound balanced, as the frequency response is very linear. Neither bass nor treble are emphasised. However, the Club, Movie, Speech and Director sound programmes are no less interesting. The Club programme boosts the bass at 50 Hz by around 6 dB, the Movie programme by as much as 10 dB. The Speech programme lowers the bass and raises the mids and highs. The Director programme can be programmed in the Captune app and then retains its properties.

High-fidelity sounds

Since the electronics of the headphones switch on automatically when the shells are turned, it is only possible to listen via cable and without any electronics once the battery has run out.

The first step is to listen to non-data-reduced recordings of sophisticated classical music via cable - and therefore without the Captune app. The sound is well-balanced, homogeneous and spatial. Anyone expecting a travel headphone to have a particularly crisp, enhanced sound will be disappointed. The PXC 550 is a paragon of balance. No pitch is emphasised, everything is heard in a neutral and transparent way. It is a pleasure to listen to chamber music or an orchestral concert. Strings come across with a fine mellifluousness, never garish and yet well defined. Voices also sound warm, clean and without emphasising sibilants.

The Harry James Big Band sounds dynamic and even smaller jazz ensembles perform with audiophile quality. It's very nice how the fine drum brushes and other percussive instruments are also clearly reproduced. The bass is deep, very clear but discreet.

However, with conventional rock-pop recordings, which are usually cut in terms of dynamics and bass, the listener sounds quite well-behaved. The bass on one of my favourite tracks in particular, the somewhat melancholy "Walk on the Water" by British melodic rock group Dare (which reminds me musically of the profound flavour of a heavy, smoky, peaty single malt like Laphroaig), is clearly underexposed, i.e. lean. The mids also sound quite harsh and thin. I hear music with a strong character with a puny sound that doesn't want to match it.

Sounds with pep

But what did the Sennheiser sound engineers give the PXC 550 the effect modes for? Firstly, a single press of the Effect Mode button and a voice announces "Effect Mode Club". Now the sound comes across the stage with significantly more power, and the bass has become much more powerful.

The sound image has also changed slightly in terms of spatiality, as the Sennheiser tinkerers have obviously also subtly manipulated the spatiality. But what would the next Effect Mode sound like? So press the button again and the voice announces "Effect Mode Movie". Now things really take off and a real steam hammer sound appears, which is just right for bass fetishists.

But if you also want to listen very quietly, you get a rich sound. At higher levels, however, the bass rumble starts to get a bit annoying after a while. Then it's back to the Effect Mode Club. In Speech effect mode, the bass is cut and the presence level is increased. So nothing for music, but speech intelligibility is significantly improved.

Captune wonder bag

Now the headphones are connected via Bluetooth. The sound is hardly any worse than via cable. The Captune app is now used for the first time. It would go beyond the scope of this report to list all the possibilities. So let's concentrate on the possibilities for influencing the sound. In addition to various preset sound programmes, there are two equalisers: one with fixed operating frequencies and a parametric equaliser that can be used to achieve practically any sound you could wish for.

Any sound can be set, from muffled booming to crystal clear. This is not necessarily useful when listening to natural instruments such as violin, cello, guitar or piano. However, when it comes to rock-pop and techno sounds that work a lot with electronic effects and sound manipulation, this opens up a real sonic playground where you can really let off steam. The PXC 550, which sounds rather well-behaved, can be transformed into a fire-breathing sound machine.

In order to make the aforementioned thin and gritty sounding rock recording enjoyable, the bass is boosted on the parametric equaliser and the presence level is lowered by 5 kHz. This gives this recording a nice punch in the bass and the annoying garishness gives way to a pleasant brilliance.

Listen quietly with a full sound

This selected curve corresponds (coincidentally?) approximately to one of the Fletcher-Munson curves, which are known as "curves of equal loudness". They describe the characteristic of our hearing that both bass and treble are perceived more softly at low sound levels than at loud levels.

These loudness-like curves make it possible to enjoy a full, round sound with a powerful bass even at low volume levels - even with classical music. The sound is not discoloured by this curve, but is pleasantly full. You can find out more about this highly interesting topic on the Internet at "aurally correct volume". Used in this way, an equaliser is much more than just a toy, especially for people who like to listen to quiet, calming music.

Conclusion

The Sennheiser PXC 550 Wireless is an elegant, high-quality and extremely versatile musical travelling companion. Clean and balanced by nature, sounding rather well-behaved with rock sounds, it can also be transformed into a fire-breathing sound machine thanks to the built-in effect modes and the Captune app. In view of the high technical effort and the resulting very good performance, the price of the handset can be described as absolutely justified.

Profile:

High-quality, ultra-modern travel headphones that can be varied in terms of sound thanks to various effect modes and the Captune app, ranging from well-behaved to fire-piercing, as well as having a very efficient and controllable noise killer - the NoiseGard.

Pro:

• soundingly versatile headset
• top processing
• efficient noise cancelling
• wireless and lightweight
• long playing time
• high wearing comfort

Contra:

• not exactly cheap

Headphones

Sennheiser PXC 550

ANC, 30 h, Wireless

143

Headphones

Sennheiser PXC 550

ANC, 30 h, Wireless

143

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