This is the second part of my drop test on the HD6XX and the Sennheiser HD660s. I will let you know how the HD6XX performs in my first drop test at the end of this blog. I am pretty disappointed that the HD6XX is doing so bad in my first drop test. After all i paid such a high price for the HD6XX and i was really disappointed too.
For people who only want to use headphones at home, the $60 HD6XX is a solid choice that offers good sound and comfort, but the Sennheiser HD660 is a better choice if you want to use your headphones in public.
The HD6XX has bigger drivers, but the sound is less detailed, while the HD660 has a more realistic soundstage with more bass, but more-than-adequate bass and treble. The HD6XX is also more sensitive, so you have to crank your volume a bit louder to get a favorable sound quality, while the HD660 has a more balanced volume curve with a more natural sound.
The Drop x Sennheiser HD6XX is one of the most important headphones released in recent years. The Sennheiser HD650 has been successfully revamped and made more affordable. However, the Sennheiser HD650 is not a new headset. It has been in existence since 2003.
And while it’s still a great sounding headset today, there are now many new options that can make for a better experience. One of these is the Sennheiser headset – the sequel to the HD650, the new Sennheiser HD660S. The sound quality of the HD650 has been improved in several ways and power consumption has been reduced, making the HD660S theoretically a more technically advanced headset.
But of course, these improvements don’t mean it’s automatically better than the HD6XX. The HD600 is still an important model today, despite the various changes it has undergone. In this article, we’ll help you decide if the HD660S is worth its significantly higher price. We examine the various differences between these two helmets. We can also help you choose the best headphones for your application. Keep scrolling for more information.
Sennheiser HD660s vs Drop HD6XX
Sennheiser HD660S
Read reviews on Amazon The Sennheiser HD660S is the latest modification to the legendary Sennheiser HD600 series. It is the direct successor to the HD650 and improves on most of the shortcomings of its predecessor, making it a more modern and competitive headset. The HD660S not only enhances the sound of the HD650, but also inherits the neutral and analytical approach of the HD600.
Sennheiser x Drop HD6XX
Drop test The Sennheiser HD6XX was one of the first headphones Drop worked with. Based on the legendary Sennheiser HD650, it has changed the game significantly by making the HD650 more affordable. And that’s without sacrificing any of the HD650’s key features.
Quality of construction
660S (Photo: Stephen Menor) 
The Sennheiser HD6XX and HD660S are very similar in terms of design and build quality. Both helmets are mainly made of high quality plastic. This gives the headphones a light weight that makes them comfortable for long listening sessions. Although the HD600 series headphones are made of plastic, they are known to be very durable.
And if any part fails, official Sennheiser replacement parts are available. Everything from the headband to the speakers can be replaced. Both headphones also use Sennheiser’s own 2-pin cable, which is very reliable. The proprietary connector need not deter you, as it is relatively easy to find replacement and spare cables. Note that the cable supplied with the HD6XX and HD660S has a different connector.
The HD6XX comes with a single cable that terminates in a 3.5mm SE connector. The HD660S comes with two cables. It comes with an unbalanced cable that connects to a 6.35 mm phone jack (with a 3.5 mm adapter) and a balanced cable that connects to a 4.4 mm Pentaconn jack. Sennheiser HD6XX Headphones (Picture: Drop) 
There are slight differences in the aesthetics of the two models. The Sennheiser HD660S has a more elegant, all-black color with the Sennheiser logo on the left side of the headband. The HD6XX has a dark blue finish (official name Midnight Blue) and the HD6XX branding on the sides.
In addition, the grilles and speakers of the HD660S are different from those of the HD6XX. We’ll talk more about this new speaker in the sound quality section. Overall, the build quality of these two headphones is not very different, despite the significant price difference. This demonstrates the HD6XX’s unbeatable price-performance ratio.
Performance requirements
Sennheiser HD660S with iFi Nano Black Label (Photo: Stephen Menor) 
One of the main differences between the two models is the energy requirements. The Sennheiser HD6XX has an impedance of 300 ohms, while the HD 660S has a reduced impedance of 150 ohms. If you are not familiar with the term headphone impedance, please read our articleto .
But in short, the impedance of the headphones is one of the factors that determine whether or not an amplifier is needed for your headphones. Since the HD6XX has a high headphone impedance, you need a headphone amplifier for best results. Compared to other headphones with high-impedance dynamic transducers, the HD6XX is not very difficult to control.
Entry-level headphone amplifiers such as Schiit Magni 3, Liquid Spark, or Zen DAC/Zen CAN should be able to use it without any problems. It will still work with smartphone dongles or built-in sound cards, but the sound will be more muted and less detailed. The Sennheiser HD660S, on the other hand, is much easier to operate because of its low impedance.
It can be connected directly to the built-in sound card of a computer, smartphone, audio interface, digital mixer or game console. That’s not a bad thing, and it’s not the first time we’ve seen a low impedance successor. The latest version of Beyerdynamic’s flagship Beyerdynamic T1 3rd Generationheadphones has also lowered the impedance from 600 ohms to 30 ohms.
The lower impedance can be very important for people like musicians who want to connect the HD660S directly to an audio interface or digital mixing board, without the need for an additional headphone amplifier. This is also important for game consoles like the Nintendo Switch, which cannot be connected to most external DAC/amplifiers.
However, we recommend purchasing a DAC/amplifier or headphone amplifier for the HD660S. The HD660S performs well when more power is applied. The sound expands and the detail throughout the range is greatly increased. If you are upgrading from an HD6XX to an HD660S and have already purchased a headphone amplifier or DAC/amp, they will also work with the HD660S.
Sound quality
Drop x Sennheiser HD6XX (Image: Drop) 
Bass
Winner: Sennheiser HD660S One of the main criticisms of the HD600 series is the bass reproduction. Compared to headphones with planar magnets and other headphones with dynamic drivers, the bass is relatively thin and less extensive.
They are still there, but they do not have the same satisfying impact and influence as other options like HiFiman Sundara. This does not mean that the bass reproduction is bad. In particular, the HD6XX is capable of producing realistic and well-defined low frequencies. It may not have the amount of bass to compete with other headphones, but it more than makes up for it in quality. And less bass leaves plenty of room for midrange. T
hat said, the HD660S is capable of major changes and improvements in bass performance. The bass of the HD660S is clearer, brighter and more consistent than that of the HD6XX. It still can’t handle the bass as powerfully as the other options mentioned, but it’s much better compared to the HD6XX and the old HD600.
Middle
Winner: Sennheiser HD660S The great strength of the Sennheiser HD600 series is its midrange. Both models have a direct mid-range sound that perfectly accentuates voices. But of the two models, the HD660S has the better specifications.
The HD6XX has a smooth, warm midrange that reproduces instruments and voices effortlessly. The HD660S, on the other hand, takes the satisfying average frequencies of the HD6XX to the next level. The approach of the HD660S is similar.
Still, it manages to add more clarity and extract more detail while maintaining the smooth nature of the HD6XX. You get a more analytical and detailed sound without sacrificing the HD6XX’s elegant approach.
Highs
Winner: Sennheiser HD660S There are no major problems with the high frequencies of the HD6XX. However, compared to other options on the market, the treble is slightly lower. As a result, the HD6XX avoids sibilance and maintains a uniform overall sound.
The HD660S once again manages to improve the high frequencies without sacrificing the smoothness that the HD6XX possessed. There is more clarity and definition in the higher frequencies. The instruments and the different elements can now be heard much better on the HD660S.
That might make the HD660S a little more than the HD6XX for some people. But overall, the HD660S still keeps sibilance and sharpness within limits.
Sound and vision theatre
Winner: Sennheiser HD660S Both headphones have a deep soundstage and a fairly accurate image. However, the HD660S is much better, both in terms of image and sound. The soundstage of the HD660S is slightly wider than that of the HD6XX. It still does not meet the level of the HD800S, but it now sounds more open than its predecessor.
The image is also more accurate than that of the HD6XX, which is probably due to the better specifications and more accurate response in the high and mid-range. More complex games and music listening are more fun with the HD660S.
Which headphones are right for you?
Best value: Sennheiser x Drop HD6XX
Drop HD6XX side grille (Image: Drop) 
By far the cheapest headset is the Sennheiser HD6XX. These headphones are in a price range where they don’t belong. You get headphones with the inner workings of one of the most famous headphones. Few things in this price range can match the HD6XX in terms of sound quality and technical capabilities. Furthermore, the lower price allows you to save more money for a powerful source that can fully power the Sennheiser HD6XX.
Best performance: Sennheiser HD660S
If you’re looking for headphones that sound great, the Sennheiser HD660S are just what you need. The specifications are much better than those of the HD6XX. Everything from the bass to the visuals to the soundstage is just better.
The Sennheiser HD660S can easily compete with most modern headphones in its price range. If you have the budget to buy these headphones, the HD660S gives you the best performance of all the headphones in the HD600 series.
Should I upgrade to HD660S?
If you already own a HD6XX or HD58X, think twice before buying the HD660S. Despite the HD6XX’s superiority in all categories, the overall sound and audio experience you get is largely the same. If that is what you are looking for, the HD660S would be a good upgrade.
However, if you are looking for a completely different sound character, it is best to listen to the other pairs first. If you are looking for a more analytical headset, the Sennheiser HD800S might be a better choice. If you are looking for a similar experience, Drop Aeon Flow X would also be a good choice.
And if you’re looking for something different, planar magnet headphones like the Audeze LCD 2C are a good choice.
Frequently Asked Questions
Are the hd660s worth it?
If you’re in the market for a new pair of headphones, you might be wondering if the HD660s are worth your money. That’s because, while they offer exceptional sound quality, the HD660s are not without their shortcomings.
They don’t come with the same amount of padding that makes the HD660s so comfortable on the ears, the cable isn’t as thick and sturdy as other models, and the lack of a microphone means you can’t use them to answer a call or take a call while you’re listening to your music.
At first glance, you might think the HD660s are too good to be true. After all, as far as headphones go, the HD660s are among the best you can buy at the moment. They’re comfortable, sound great, and look good. The only downside? They’re expensive. Another way of looking at these headphones is that they’re worth every penny.
Is HD6XX same as HD650?
Today we will be testing the Sennheiser HD660s vs Sennheiser HD6XX. We’ve done this comparison in the past. There are some similarities between the two, but also some major differences. The Sennheiser HD660s are comparable to the Sennheiser HD6XX.
Both of them have a big bass but they also have a more “fun” sound. The Sennheiser HD6XX is a great headphones for those who need a little bit more bass, and it’s good for all kinds of musical genre and for the movie. The Sennheiser HD660s is also a great music headphones, but it’s not the best for every kind of music.
The Senn The Sennheiser HD660S is one of the most popular and most recommendable open-back headphones. It may not have the audiophile sound of the HD650, but it’s a very good alternative, especially for those who prefer open-back headphones. Benefits of the HD660S include a comfortable design, a closed back with a pleasant sound, a strong presence of bass, and a durable build.
What is HD6XX?
One of the most popular questions we get is, “What is HD6XX?” The HD6XX is a new headphone model from Sennheiser that was announced in March 2018. Although it was first launched as just a new name for the HD660S—a headphone that has been in production since 2017—Sennheiser today announced the new model is a major upgrade in that it’s the first high-end headphone to use the latest HDX technology.
These days, many headphones have evolved to the point where they can be considered “high-end.” What does that mean? It means that the headphones can have a very crisp and detailed sound for listening to music, and they can be used with a mobile phone.
