Hands-On Review: Sennheiser HD 490 PRO Open-Back Headphones

Hands-On Review: Sennheiser HD 490 PRO Open-Back Headphones

Over the years, Sennheiser has become a name ubiquitous with headphones. Historically well regarded by audiophiles and professionals for the sleek, reliable build quality and smooth, balanced sound of its HD series headphones, Sennheiser is trying to up its game even more with a new addition to the lineup: the HD-490 PRO .

Sennheiser HD 490 PRO Professional Reference Open-Back Studio Headphones
Sennheiser HD 490 PRO Professional Reference Open-Back Studio Headphones

Aiming to maximize clarity, comfort, and reliability all at once, the HD-490 PRO are open-back headphones with new Open-Frame Architecture technology (more on that later) and a state-of-the-art neodymium magnet at the core of its sound reproduction. But before I make you dizzy listing specs, let’s get to the important part. On to the review!


I was presented with the HD-490 PRO Plus headphones, a version that, along with the detachable mini-XLR to 3.5mm cable, mixing ear pads, and producing ear pads, also includes an extra headband pad, an extra, longer cable, and best of all, a great semi-hard travel case with a plush, well-padded interior. This case is extremely convenient when you need to transport your cans from one place to another (since they are not small) and includes tons of convenient zippered compartments, cutouts, and even a mesh pocket for organizing and storing accessories, such as the earpads.

As one would expect of a quality Sennheiser product, these headphones are elegant in looks—and they are built well. Every part of the exterior feels solid and durable, and the earphones feature a snazzy open-mesh grille that lets you see the driver assembly. This feature is more than just for looks, though; it also helps improve ventilation. Each earcup swivels with full 180-degree rotation. Despite the German-engineered build quality we have come to expect from Sennheiser, the HD-490 PROs remain lightweight and flexible.

My favorite part of the build quality is the comfort. The plush earcups are comfortable and soft, which is a real benefit for long listening or mixing sessions that may put a strain on your head. The luxurious comfort is further supported by well-placed padding on the headband, which is often the most uncomfortable part of headphones.

These headphones come with two sets of swappable earpads, one for mixing and one for producing. According to Sennheiser, each earpad set has its own unique sound signature and is designed to eliminate ear fatigue and pinpoint frequencies. Although they are both comfortable, at the time of this review, I cannot say exactly how their sonic signatures differ, but the difference is subtle. Most importantly, Sennheiser smartly designed both earpad sets to be completely washable, which in this post-COVID era, is a welcome feature.

Sound Quality

While ergonomics and comfort are important when picking a set of quality headphones, obviously, the sound is the main attraction. You want to make sure the unique sound character is to your liking, and when intending to use them for professional applications, an honest, uncolored frequency response is vital. I’m happy to report that these headphones pass the smell test and then some, and they may in fact be the best sounding pair of Sennheiser HD-series headphones I’ve ever used.

In my experience with testing the HD-490 PROs against a wide array of sonic material, from heavy rock and funk to jazz, hip-hop, and electronic music, I found the sound response to be noticeably smooth, big, and neutral, offering a truly realistic frequency response that often made me feel as though I was listening to mixes the way they were intended by the original engineer. Low-frequency content sounded fat, well rounded, and warm without overwhelming the other frequencies. High-frequency material was balanced, airy, and well defined.

Technical Highlights

This is all likely due to some innovative design features built into the HD-490 PRO. Sennheiser’s Open-Frame Architecture reduces the total harmonic distortion and minimizes resonance, improving audio accuracy. This feature really seems to make a difference in ensuring that no pesky resonant frequencies cause unwanted distortions or colorations of content, especially low or mid-range frequencies, making the whole frequency spectrum feel smooth, natural, and dynamic.

An innovative low-frequency cylinder system provides full, accurate, and clearly defined low end. The earcups are geometrically angled to optimize transducer placement for a consistent listening experience. Furthermore, Sennheiser used state-of-the-art neodymium magnets with ultralight voice coils for superior driver performance and efficiency, allowing the 38mm dynamic drivers of these headphones to often feel more like 50mm drivers.

Even the detachable cable has gotten a big upgrade over previous HD-series open-back headphones. A locking mini-XLR plug is used for the earphone connection end and can be freely plugged into either the left or right ear, facilitating any studio setup you might encounter, a really nice feature to see as someone who often has had to deal with tangled wires in studios. The cable uses a patented cable coil structure that blocks cable-borne noise, ensuring a clean signal.

Finally, the open-back design is an important element here. Sennheiser claims that the open-back design provides an extremely wide, dimensional sound stage and ultra-precise localization of sounds. I must agree, and while I have often gone back and forth between open-back and closed-back headphones when trying to find my preference, the HD-490 PROs have made me a believer in the open-back design, because the frequency response felt far more organic and stereoscopic than anything I’ve heard from closed-back headphones.

Unique Features Worth Mentioning

Regarding open-back headphones, while this design offers a lot in the way of a natural, wide-open sound stage, it doesn’t come without its drawbacks. The biggest downside to open-backs is the way in which your environment can affect the sound response. Since sound naturally bleeds between the headphones and your surrounding space, this means the headphone sound and your room sound can interact. People around you will most likely hear the sound coming out of your headphones, and untreated rooms with excessive reflections can also impact the way you hear sound coming from your headphones.

To address this, Sennheiser includes a free download of the Dear Reality dearVR MIX-SE plug-in, available in AU, AAX, and VST3 plug-in formats for DAWs. This cool little plug-in uses IRs and algorithms to emulate the room response of various world-class studio mixing rooms. With this plug-in, you can select your specific headphone model and your desired mixing space and enjoy a pro-level mixing experience that helps to compensate for any reflections in your environment that are altering your headphone sound.

The HD-490 PRO headphones also come with some well-met accessibility features for those with impaired vision. The earcups sport braille-guided L and R impressions, which can be felt with your hands, so you always know which earcup is which. The earpads also include grooves for eyeglasses, making them much more comfortable to wear if you require glasses to see. It should probably be noted that a colleague of mine found the slightly raised L and R symbols to be uncomfortable with bass-heavy audio content. However, since I did not experience this with even the most bass-intensive, diaphragm-pushing music I had, I believe most users will not even notice they’re present.

Final Impressions

The reality is that the HD-490 PRO headphones are some of the best open-back headphones Sennheiser has produced yet. I’d love to sit here and nitpick tons of little shortcomings or problems (who doesn’t like to sound smart and superior?) but the truth is that there is little to criticize here. The headphones produce a smooth and dynamic sound stage with very accurate frequency response, making them ideal for audiophiles/enthusiasts seeking quality cans for their media consumption, and professional engineers and producers who desire an honest, high-performance reference for mixing and producing.

For more information about these new headphones, including additional features, specs, and highlights, be sure to check out the detailed product page for the Sennheiser HD 490 PRO and HD-490 PRO Plus. Or drop us a line below, and we’ll do our best to reply to your comments and questions.