If you’re looking to get a pair of mid-range open-back headphones, you’ve probably come across the Beyerdynamic DT 1990 Pro and the Sennheiser HD660S due to their popularity. While these are considered mid-range because of their pricing, they can absolutely be anyone’s endgame pair due to their excellent build quality and high quality sound. So which of these two pairs of headphones is right for you? Our detailed Sennheiser HD660S and Beyerdynamic DT 1990 Pro review and comparison below should be able to help you decide.
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Beyerdynamic DT 1990 Pro vs Sennheiser HD660S Comparison Chart
Design and Build Quality
Both the Beyerdynamic DT 1990 Pro and Sennheiser HD660S are built to last, but the former have the advantage here due to their more premium build.

When it comes to looks, the Beyerdynamic DT 1990 Pro have a more striking design than the Sennheiser HD660S. The Beyerdynamic DT 1990 Pro look like a more premium version of the Beyerdynamic DT 990 and DT 770. The build quality of these headphones is excellent, featuring a combination of metal and a tiny amount of plastic. You can feel that they are premium headphones when held due to their heft and the feel of the materials.
Meanwhile, the Sennheiser HD660S have a more minimalist design that they share with every headphones in Sennheiser’s HD6x0 lineup. The HD660S come with a black matte finish and the grills on the ear cups show off the drivers for a professional look. The build quality is great. Even though these are made of mostly plastic, the parts used feel solid. Sennheiser headphones that use this frame can be easily disassembled with minimal tools, so if a part breaks, you can easily order individual replacement parts.
Both headphones have detachable cables that contribute to their longevity. The Beyerdynamic DT 1990 Pro use mini XLR connectors while the Sennheiser HD660S use proprietary 2-pin cables. You can easily buy replacement cables for both of them. The Beyerdynamic DT 1990 Pro come with two audio cables (1x coiled and 1x straight), a 3.5mm to 6.35mm adapter and a hard case. On the other hand, the Sennheiser HD660S come with a 6.35mm single-ended cable, a 4.4mm balanced cable and a 6.35mm to 3.5mm adapter. No protective case, though.
Comfort
The Sennheiser HD660S are slightly more comfortable than the Beyerdynamic DT 1990 Pro due to having a more relaxed clamping force.

For a lot of people, comfort is as important as sound quality when it comes to headphones. After all, what’s the point of a good sounding pair of headphones if you can’t wear them for extended periods without developing fatigue or sore spots on your ears. Fortunately, both the Beyerdynamic DT 1990 Pro and Sennheiser HD660S excel in this department.
Both headphones come with plenty of padding on their headbands so you won’t feel pressure even when you wear them for long periods. Their ear cups also have sufficient amount of padding, and they are deep enough that even those with larger ears will have no issues. That said, it’s important to note that the Beyerdynamic DT 1990 Pro have circular ear cups while the Sennheiser HD660S have oval-shaped cups.
As for clamping force, the Beyerdynamic DT 1990 Pro’s is tighter than that of the Sennheiser HD660S. If you still find the clamping for to be too tight after a considerable amount of use, you can bend the metal parts of the headbands to lighten the clamping force, but you should do so carefully as you don’t want to damage these pricey headphones.
Sound
The Beyerdynamic DT 1990 Pro have a slightly V-shaped sound while the Sennheiser HD660S have a warm neutral sound profile.

These headphones couldn’t be any more different when it comes to how they reproduce sound. The Beyerdynamic DT 1990 Pro have a more V-shaped sound with a slight bump in the bass region and a significant boost in the treble region. The mids are just slightly recessed. The overall sound is a fun one with plenty of oomph, thump and slam, due to the bump in the bass region. However, it can also be a bit harsh and fatiguing if you are treble sensitive due to the spike in the upper treble region.
Meanwhile, the Sennheiser HD660S have a warm neutral sound with a considerable roll-off in the sub-bass and treble region. The strength of the HD660S is in the forward mids that make vocals and instruments a bit more forward. The sub-bass roll-off results in a lack of thump and rumble, and the dip in the treble region makes the headphones sound a bit dark and veiled. That said, the resolving ability of the HD660S is still quite good, so you can still hear details in busy music even with the dip in the treble range.
These headphones sound quite different. If you prefer a fun sound signature with elevated bass and treble, the Beyerdynamic DT 1990 Pro will be more to your liking. On the other hand, if you prefer a more relaxing sound signature that you can listen to for a long period, the Sennheiser HD660S will be right up your alley.
Verdict
Get the Beyerdynamic DT 1990 Pro if you want an energetic and fun sound signature, but if you prefer a warm and relaxing sound, the Sennheiser HD660S will be better for you.
Beyerdynamic DT 1990 Pro
V-Shaped sound

Sennheiser HD660S
Warm neutral sound

You can’t go wrong with either of these headphones as they have excellent builds and they are comfortable enough for long listening sessions. Choosing between the two will come down to your preferred sound. The Beyerdynamic DT 1990 Pro headphones have a more V-shaped sound that results in a more “fun” listening experience with plenty of bass and treble. It can be fatiguing, but if you aren’t treble sensitive, you might like this pair of headphones.
The Sennheiser HD660S, on the other hand, provide a more relaxing sound with more forward mids. The sound can be dull if you’re a basshead or a treblehead. But if you want a relaxing pair of headphones that focus on vocals, the Sennheiser HD660S are up there with other Sennheiser HD6x0 offerings as some of the best.
FAQs
It depends. The Beyerdynamic DT 1990 Pro do not require that much power since they only have an impedance of 250Ω and 102dB sensitivity. If your device can drive them to unlistenable volumes, then you don’t need to get a dedicated headphone amp.
The Beyerdynamic DT 1990 Pro have an impedance of 250Ω.
It will depend on your source. The Sennheiser HD660S are not that hard to drive—they have an impedance of 150Ω and 104dB sensitivity—so you can easily use them even with your smartphone.
Yes, the Beyerdynamic DT 1990 Pro are excellent for gaming due to their wide soundstage and accurate imaging.