With the HD 620S, Sennheiser wants to convince audiophile users that a relatively inexpensive closed headphone can sound as fantastic as a high-priced open headphone and can shine in the quiet of the home, on the go or when gaming. The practical test shows that the plan largely works.
Bluetooth is all well and good, but audiophile users prefer to listen to music in the highest quality via wired headphones, preferably with open headsets. These are not only very comfortable to wear thanks to their airy earcups, but also offer a very spatial, unadulterated sound. On the other hand, they let all noise through in both directions with almost no insulation. The Sennheiser HD 620S is supposed to be the perfect compromise and, as a closed HiFi headphone with effective passive insulation, sounds as good as open high-end headsets.
Comparatively inexpensive
![The shell cushions can be changed.](https://insanityflows.net/wp-content/uploads/2024/07/sennheiser-hd-620s-is-closed-but-open-for-everything.jpg)
![The shell cushions can be changed.](https://insanityflows.net/wp-content/uploads/2024/07/sennheiser-hd-620s-is-closed-but-open-for-everything.jpg)
The shell cushions can be changed.
(Photo: kwe)
The HD 620S costs 350 euros, which is a lot of money. Audiophile hi-fi headphones are often much more expensive, however; the Sennheiser HD 820, which is also closed, was launched for just under 2000 euros, for example. However, according to the manufacturer, the newcomer has the DNA of the HD 600, which is over 20 years old and set standards with its open design and is still available for 390 euros.
The HD 620S has largely adopted the design of its stablemates. As a cheaper representative of the HD guild, it is made mainly of plastic except for the steel headband and steel-reinforced ear cup covers, but appears robust and very well made. Although it has a fairly strong contact pressure and weighs 326 grams, it is equipped with thick padding but is extremely comfortable to wear.
![A cross-section through the mussel shows the structure.](https://insanityflows.net/wp-content/uploads/2024/07/1721337646_746_sennheiser-hd-620s-is-closed-but-open-for-everything.jpg)
![A cross-section through the mussel shows the structure.](https://insanityflows.net/wp-content/uploads/2024/07/1721337646_746_sennheiser-hd-620s-is-closed-but-open-for-everything.jpg)
A cross-section through the mussel shows the structure.
(Photo: Sennheiser)
The scope of delivery is sparse. In addition to a fabric carrying bag, the headphones only come with a detachable, 1.8 meter long cable including a jack plug adapter from 3.5 to 6.3 millimeters. There is no USB-C adapter, so you still have to go shopping to connect them to many current smartphones.
Good passive insulation
The headphones actually do a pretty effective job of isolating ambient noise, which Sennheiser says is thanks in part to the steel plates in the ear cup covers. This isn't comparable to active noise cancellation (ANC), but in most everyday situations you can listen to music almost undisturbed, as promised.
The sound is produced by 42-millimeter transducers with membranes that have a diameter of 38 millimeters. They are not aimed directly at the ears, but are angled. This is to produce the most spatial sound possible with a wide stage, reminiscent of a perfect stereo triangle. Ultra-light 150-ohm aluminum coils are intended to ensure clarity and precision.
Sound meets high expectations
In practical testing, the Sennheiser HD 620S can meet the high expectations. Equipped with high-quality material, it opens up an astonishingly wide stage, the spatiality of which almost reaches 3D level. The bass has a lot of oomph and pressure. But it is always controlled and does not interfere with the midrange, which is extremely well defined and placed.
In combination with the crystal-clear highs, the headphones allow you to discover details that you hadn't noticed before. The neutral sound that is typical for Sennheiser is sometimes almost brutally analytical, but it doesn't cross the line. It's no wonder that the HD 620S is a lot of fun with jazz, but in practical tests it also excelled with every other style of music.
Gamers will also enjoy the headphones. In the test, their precise spatiality enhanced the spooky atmosphere in “Resident Evil 4” and really made a blast in “Star Wars Jedi: Survivor”.
Conclusion
The Sennheiser HD 620 S is indeed the all-rounder that was promised, offering the highest level of HiFi sound in the privacy of your own home, but also cuts a fine figure on the go or when gaming. There are headphones that produce even better sound, but are much more expensive. Others offer more effective noise cancellation with ANC, but don't sound nearly as good.