This week, we’re reviewing no less than three Bluetooth headphones, namely, the Sennheiser HD 4.40 BT Wireless, Sennheiser HD 4.50 BTNC Wireless, and Sennheiser PXC 550. The first two models released by the German brand are cost-effective wireless headphones (<200€), one of which even features active noise cancellation technology. The third model is directed towards audiophiles and is fitted with a USB digital input to connect a computer or smartphone.
Sennheiser HD 4.40 BT Wireless
The Sennheiser HD 4.40 BT Wireless Bluetooth headphones stand out as the German manufacturer’s first wireless model and next of kin to the Sennheiser HD 4.30i (exclusively wired connection). These circumaural headphones sit snugly around the ears, so much so that some adjustments might be necessary to make sure the auricle is not in direct contact with the earcup padding. The memory foam earpads are thick and the isolation from outside noises is particularly effective, with a notable amount of pressure applied to the head. Nevertheless, these headphones are comfortable and sit well on the head, notably due to their light weight. As a result, the Sennheiser HD 4.40 seems to disappear and lets the user move around while offering adequate isolation from surrounding noises in a home setting. When it comes to street noises, the isolation is not as effective, and you can either make do with it or consider acquiring the Sennheiser HD 4.50 BTNC Wireless featuring Noise Guard technology.
The Sennheiser HD 4.40 BT Wireless’s specs are exemplary: Frequency response ranging from 18 Hz to 22 kHz, impedance rating as low as 18 Ohms (for easy amplification with a wired connection), sensitivity rating of 113 dB (particularly high), a dual microphone (for phone calls), a lithium-ion and polymer battery (25h autonomy for a 2h charge), and a Bluetooth receiver with NFC pairing compatible with SBC, AAC, and aptX protocols. The three main compression technologies are therefore handled.
Sennheiser supplies a micro-USB cable for battery charging, a 3.5mm mini-jack to mini-jack interconnect cable and a soft carrying case with each set of headphones. Note that the Sennheiser HD 4.40 BT’s earcups can be folded for easy and discreet storage.
The Sennheiser HD 4.40 Wireless BT is particularly easy to use. The pairing mode is automatically activated when the headphones are powered on for the first time (with partially charged headphones). Once the headphones are successfully paired with a smartphone, for example, a voice message confirms the connection. The playback controls (previous/next track, pause), as well as the volume control, are situated on the right earcup. A beep confirms each incremental adjustment in volume. A slight adjustment period is necessary to get used to the relatively small buttons. Since the sounds picked up by the dual microphone are reproduced by the transducers, you can hear yourself talk during phone calls.
The difference between a Bluetooth and a wired connection is such that we decided to review the two types of listening experiences separately.. We listened to the headphones using Bluetooth SBC and aptX transmission codecs and it comes as no surprise that the aptX codec is the most enjoyable of the two. The mids are a bit softer and the highs smoother. The Sennheiser HD 4.40 BT Wireless’ sound signature is mostly centered around the mids, without neglecting the highs and lows. The overall sound is coherent but lacks excitement. By comparison, the Sennheiser Momentum In Ear Wireless Bluetooth headphones provide solid lows while clearly highlighting the highs. If we were to compare these two models, we would have to say that the Sennheiser HD 4.40 BT Wireless boasts a certain neutrality. Sennheiser offers the possibility to adjust the sound via its CapTune mobile app (for iOS & Android). This is certainly a good thing, although the app has a bone to pick with FLAC files and refuses to read them (it seems that the issue only arises with certain smartphones).
We tested the wired connection with a Xiaomi Redmi Pro smartphone and an Encore mDSD DAC. The listening experience is a lot more exciting, especially in the lower end of the spectrum. Listening to pop songs suddenly becomes a lot more fun.
What we liked:
- The comfort
- The quality of phone calls (the microphone is really good and the sound is clear)
- The battery life (the headphones were still running after two 8-hour-long listening sessions)
What we would have liked:
- A wider soundstage
- A more expressive amplifier
- Brighter highs
Sennheiser HD 4.50 BTNC Wireless
The Sennheiser HD 4.50 BTNC Wireless headphones are heir to the HD 4.40 BT Wireless but stand out for the addition of active noise cancellation technology. Moreover, the thickness of the earpads and the depth of the earcups are different. And this counts for a lot.
As a reminder, the Sennheiser Noise Guard system uses two microphones to pick up and measure ambient sounds in order to cancel out low frequencies. To do so, the amplifier generates a sound similar to that which is picked up, except in phase inversion. The external parts of the membrane act as a resonator and low frequencies cancel out undesirable sounds. In the case of the Sennheiser HD 4.50, this system is positively convincing. We tested the headphones as a car passenger and noticed that even the noise of an aging diesel engine was indisputably attenuated.
Once the undesirable outside noises are canceled out, the Sennheiser HD 4.50 BT headphones logically exceed the performance of the 4.40. Moreover, the Noise Guard system slightly colors the sound and this results in a pleasant sound signature.
Note that the Noise Guard system can be deactivated and that it can also be used with a wired connection. We were able to listen to the Sennheiser HD 4.40 BT headphones two days in a row (about 8h a day) without running out of battery.
The positive and negative points are similar to those of the 4.40 BT Wireless. We were a bit taken aback by the presence of interference caused by airflow during on-the-go listening (by the ocean, for example). Such a drawback is pretty much non-existent with Bluetooth headphones such as the Plantronics BackBeat Pro, for example.
Sennheiser PXC 550 Wireless
The Sennheiser PXC 550 Wireless is the manufacturer’s flagship model. More functional and efficient than the 4.40 and 4.50 models, it offers a more adventurous listening experience. It features the same SBC/AAC/aptX Bluetooth receiver and semi-touch controls, and it also benefits from the Noise Guard 2 system, which Sennheiser has described as even more impressive.
Let’s start by highlighting the fact that the Sennheiser PXC 550 Wireless’s micro USB port is not limited to charging its battery. The port can be used to transfer digital audio data from an iPhone, iPad, Android smartphone (featuring an active USB audio output), or computer (Windows, Mac OS, Linux). The Sennheiser’s integrated DAC is therefore put to use for the digital-to-analog conversion.
Another strength of the Sennheiser PXC 550 Wireless is the EQ presets, which can be activated by simply pressing a button. Three equalizers are available: club, cinema, and voice. Other EQ presets can also be applied using the Sennheiser CapTune app. While the app cannot read FLAC files stored on your smartphone, it is still a convenient solution to adjust the settings of the Sennheiser PXC 550 Wireless, including choosing the language of vocal alerts and fine-tuning the active noise cancellation system. The noise cancellation system can be set to one of two positions, one of which applies an adjustable noise cancellation filter (from 1% to 100%). Once adjustments are made to the Noise Guard system in the app, the settings are memorized and applied to the headphones, regardless of the Bluetooth source (computer, TV, etc.). The second position applies the full noise cancellation filter.
The Sennheiser PXC 550 Wireless’s Noise Guard active noise cancellation system is extremely effective and easily cancels out the noise of a bus engine or passing train.
Lastly, we should point out that Sennheiser decided to make the tonal EQ applicable to Bluetooth, USB, and analog (mini-jack input) sources. This means that analog signals are digitized and unfortunately undergo damaging compression.
The Sennheiser PXC 550 Wireless is more comfortable and is fitted with softer memory foam earpads and higher earcups. The pressure applied to the head is therefore less noticeable and the listening experience a lot more enjoyable. The Sennheiser PXC 550 Wireless is also more user-friendly thanks to the touch controls on the right earcup. Musically speaking, it is a completely different world. The soundstage is wider, the delivery more dynamic and lively. Nevertheless, the default balance can become a bit tiring over long periods of time, and we felt that the cinema mode was more enjoyable thanks to more moderate mids and reinforced lows. The resulting listening experience is more entertaining.
What we liked:
- The outstanding comfort
- The open microphone mode (for conversation)
- The highly efficient noise cancellation system (-30 dB)
- The EQ presets
- The USB digital audio input
- The battery life (two 8-hour-long sessions in Bluetooth mode with noise cancellation)
- The on/off switch via earcup rotation
What we would have liked:
- A non-digital line input to connect an external amplifier
The Sennheiser HD 4.40 BT Wireless Bluetooth headphones shine for their efficient passive isolation and detailed and sensible sound restitution. However, due to the absence of an active noise cancellation system, we recommend using this model primarily at home. People who like to listen to music on-the-go will find a better match in the Sennheiser HD 4.50 BTNC Wireless, whose active noise cancellation system also enhances the listening experience in quiet environments (increased dynamic range). For frankly expressive sound delivery, great comfort, and extremely efficient noise cancellation, the Sennheiser PXC 550 Wireless is the way to go. Lastly, the microphones used for all three models are excellent.French