Design and workmanship
The HD 250BT appear extremely slim, minimalist and streamlined. Weighing in at just over 127 grams, these black on-ears do not weigh much on the head. This is also because the headband, which is made entirely of plastic, does not have any padding. Depending on the size of your head, this initially causes pressure on the skull, but this is reduced with the appropriate adjustment of the ear cups. These can be adjusted in twelve steps, and the appearance of these headphones reminded us a little of Sennheiser’s legendary DJ accessory the HD 25. However, according to the manufacturer, the design and name are supposed to be coincidental, so that this model joins the HD-BT series (HD 350BT and HD 450BT) to complete the series.
These headphones’ controls are equally purist, with just three small buttons on the right ear cup (more on that later), a status LED and the USB-C connector for recharging.
There’s not much to complain about in terms of workmanship, which as is typically good for Sennheiser and seems appropriate for the price. The leatherette ear pads can be removed and cleaned or replaced if necessary. For our tastes, there is only the headband that could have been given a little more attention, and this is why we didn’t give them top marks for wearing comfort.
Bluetooth and operation
These headphones support Bluetooth 5.0 and offered a stable connection without dropouts inside a two-storey flat. Pairing is done quickly and is acknowledged via voice prompt, and the HD 250BT are well equipped in terms of Bluetooth codecs. In addition to the SBC standard, these headphones also offer the high-resolution AAC as well as aptX and aptX LL. The latter codec is rarely found in this price range, which will particularly please anyone who streams movies and series, because thanks to aptX LL (Low Latency), the picture-sound offset is so small that no delay is perceptible.
The 250BT are controlled via the buttons on the right side of the ear cup. The middle button not only switches on and off or pairs, but also controls media content: a short press plays or pauses music, a double and triple press jumps the track forward or back. Calls are also managed with this button (answer, end and reject), and a two-second press on the volume control minus button mutes or reactivates the microphone.
Also, these headphones can handle multipoint connections and remember the connection profiles of up to eight (previously connected) devices. If a ninth device is added, the connection data of the least used Bluetooth device is automatically deleted.
The rechargeable battery provides up to 25 hours of power (measured with the Bluetooth codec SBC); a full charge with the supplied 50-centimetre cable takes around 3.5 hours, during which the headphones cannot be used. There is also no quick-charge function, but a good feature is the battery status query, which provides information when no music is being played is activated by pressing the minus button.
Smart Control App
If you are not satisfied with the sound or would like a boost in certain frequency ranges, you can make an adjustment using Sennheiser’s free Smart Control app (iOS and Android). This provides a 3-band equaliser; here, the settings can be saved on the headphones and also used without the app. At the moment, the only pre-sets available are “Neutral” and “Film”, but this could be expanded with an update. Speaking of updates, the app can also be used to install firmware updates and manage other Sennheiser headphones.
The dynamic 32-millimetre drivers reproduce frequencies between 20 Hz and 22 kHz. The bass range is solid, not overbearing, and forms a slightly warm foundation, which works well across genres. The bass is clearly delineated, leaving room for the midrange to reproduce the subtleties of individual instruments with the necessary attention to detail. Although the mids seem slightly restrained, which takes the edge off things like metal riffs, vocals always remain intelligible, even if they don’t reach the presence of more expensive models. The highs easily manage to reproduce important high-frequency signal components without sibilance and sharpness – but they don’t leave the liveliest impression. The 250BT also reproduce movements of individual sound events or deep reverberation rooms satisfactorily, although these headphones are not the loudest.
The HD 250BT can also be used to make phone calls. This is done with an omnidirectional microphone that operates in a frequency range of 100 Hz to 10 kHz and provides good and clear speech intelligibility under optimal conditions.