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Sennheiser HD650 Vs HD660S: Which Is Better in 2023?

In this updated guide, I will put Sennheiser HD650 vs HD660s to the ultimate test.

For those who want to cut the chase, the winner of the comparison is the HD660S Sennheiser headphones.

But why do they win? And what if I hate Sennheiser like my enemy #1?

We have dealt with everything in our superb guide. Let’s begin:

Sennheiser HD650 At A Glance


  • The HD650S provides excellent audio reproduction.
  • A well-executed design
  • Stable and comfortable design.


  • A bit colored bass
  • Trebles need improvement.

These are truly excellent all-around, with the comfort and sound signature to allow for extended hours of enjoyable listening. Learn More

Sennheiser HD660S At A Glance


  • A fantastic soundstage.
  • Design.
  • Comfort.
  • It is portable and may be used with a variety of devices


  • It isn’t worth it at this pricing

They will take your listening experience to new heights, especially while listening at home. It’s your go-to choice if you want to notice the difference between soundstage for deep listening. Learn More

Philips Fidelio X2HR: The Surprising Choice!

Alternative Product

HD650 Vs HD660S


  • Comfortable to wear even during intense listening sessions.
  • Sound Profile is balanced for neutral listening.
  • Durable design.
  • Premium look and feel.


  • Customers have objected to plastic body build.

If you can manage tangling wires, you can comfortably use these Philips headphones for brilliant music listening sessions (gamers will love them too!)

HD650 Vs HD660S Comparison Table

Connectivity TechnologyWiredWired
Fit TypeOver EarOver-Ear
Impedance300 ohm150 Ohm
Item Dimensions31.5 x 25.5 x 11cm25.7x 10.79 x 32 cm
Item Weight258.88 gm263.03gm
Microphone Form FactorNo MicrophoneWithout Microphone
Model NumberHD-650HD-660S
Special FeaturesWith Earphone Removable CableLight Weight Removable ear pads

I love listening to acoustic music, though I listen to heavy metal sometimes. That’s why I decided to compare the two best open-back headphones from Sennheiser.

Sennheiser: An Overview of the Company

Sennheiser is a household name in professional and consumer audio devices and has been for nearly 60 years.

Today, the company is still controlled by Sennheiser family members in Germany, and the product line has evolved from microphones to telephone accessories, aviation headsets, and, of course, headphones.

Sennheiser was the first to introduce open-back headphones to the world in 1968!

Instead of following the present trend of periodically updating product ranges, Sennheiser prefers to cling to its winning formulations. A microphone initially introduced in 1960 is still available today, while the current collection includes a model from the 1980s!

Sennheiser H650 Full Review

HD650 Vs HD660S
  • Headphones with an open back
  • Dynamic drivers
  • The impedance is set at 300 ohms.
  • Sensitivity (dB): 103
  • Frequency Range: 10Hz – 41,000Hz
  • Plug: 6.35mm TRS with 3.5mm TRS adapter
  • Weight: 260 g

What’s Inside The Box?

  • HD650 headphones
  • 3m detachable OFC cable with a 6.35mm plug
  • Flexible cable adaptor for 3.5mm jacks
  • Instruction manual

The pamphlet includes images of both XLR and Pentacon balanced cable options. Both are not included but can be ordered from a variety of third-party cable manufacturers.

Sennheiser 650
HD 650 Review

Cool Design

The over-ear HD650 is the third model in a range that began in the early 1990s with the HD580 and continues the design language of the family. Overall, the design is more functional than luxurious, in our opinion.

The glossy plastic used in the construction is of excellent quality, and metal is used where it matters, such as in the adjustable headband frame and the external mesh shielding the driver. There are no concerns about durability here.

The headband cushioning has a cutout in the center that works wonderfully for the head, as long listening sessions typically cause a pressure point.

Sennheiser employed several headband padding designs on previous versions in the family but has now settled on the center cutout on all current models (HD600, HD650, HD6xx, and HD660).

Another noteworthy feature of the headband is its clamping force, unquestionably greater than typical. It never comes to the point of being uncomfortable, and it tends to go away with time.

A marketer would describe them as “reassuringly sticky.” Fortunately, the headband can be adjusted for a lighter clamping force with some careful bending.

They get a little warm after a while of listening, but not unbearably so, and they work nicely with glasses. The velour pads are responsible for much of the warmth. These are hard rather than fluffy, but you’ll like the comfort and find this a better material for lengthy listening sessions than leather (especially faux leather).

The earpads are appropriately deep and had no problems with our ears hitting the foam covering the drivers, which can be a problem with more slimline designs. They wear out with time, but replacements are inexpensive and easy to acquire.


Sennheiser 650

HD650 doesn’t have the most minimal design and that’s for a good reason. A 42mm transducer is nestled inside, driving a 38mm diaphragm with an aluminum voice coil.

Sennheiser claims that the design tolerances are extremely precise, with hand-picked drivers matched to 1 dB, making them ideal for audio professionals and audiophiles.

They’re not the easiest headphones to drive, having a 300-ohm impedance, but they’ll work with a smartphone and reward you with making your amplification better.


Sennheiser 650
Sennheiser 650

Before we go into the sound, let’s talk about amplification. Because the HD650 is infamous for requiring a significant amount of power from the amplifier, many owners have switched to OTL (Output-Transformer-Less) amps.

This tube amplifier design generates a high voltage, which is ideal for higher impedance headphones such as the HD650. Take a look at this full guide on the bottle head cracks to learn more about one of these headphones’ most popular amp alternatives.

We used stock wiring with a custom-terminated balanced XLR plug in all situations, and no equalization was used.


Entering a headset review that has been on the market for over 20 years is no easy task. The internet is already clogged with several HD650 reviews, making it difficult to clear one’s mind of all that accumulated knowledge.

When the music begins to play via these headphones, it’s easy to switch off anything else on your mind and sit back and enjoy. Let’s start with what these headphones aren’t: they’re not in any way objectionable. Instead, we’d compare them to a comfortable pair of slippers (or gloves if you’re not a slipper person).

The HD650 doesn’t have the most expansive soundstage, and we’ve heard many pairs of headphones and IEMs that do a better job in this department. There’s no fear of that with the HD650, as the music is largely heard between your ears.

Tonal Balance

Their neutral to warm tone balance allows for pleasant listening across a wide range of music, but the detail is not lost, and it’s clear why they’re marketed to engineers as well as audiophiles.


The HD650 was released seven years after the successful HD600 to create a more engaging sound and richer bass.

Sennheiser succeeded in this endeavor. The bass on these headphones is strong yet well-controlled, making it simple to follow the deeper notes on a bass guitar or synthesizer.

Sure, there are headphones with even more apparent sub-bass, but the HD650 excels in sheer listenability without fatigue.

Given adequate amplification (these headphones are not the easiest to drive), they deliver bold, powerful bass that entertains while never dominating the song. For example, turn up the volume on Gorillaz’s Last Living Souls.


The HD600’s reputation was based on the reproduction of the mids, and the HD650 expands on that foundation, offering a similar, albeit somewhat less sharp, midrange presentation than its sibling.

These headphones reproduce vocals nicely, and we particularly like how they reproduce masculine vocals. Choose practically any Chris Jones song to get the most out of these headphones.

To our ears, female vocals occasionally sound slightly more veiled. It’s subtle, but if female musicians make up most of your audio collection, it’s worth paying particular attention to your listening tests.

Fairytale by Lianne La Havis is beautiful music with precise mic voices that illustrates this for me, with a subtle ringing and hollowness.

Having said that, there’s a smoothness and refinement in the midst. We feel that the strong but never harsh presentation of mids on the Sennheisers allows us to forget about the headphones and dive deeper into music, whether for vocals or instruments. That is a gift that only the best hi-fi can provide.


How much you appreciate the high end of the HD650 is a matter of personal preference, more so than the bass and midrange.

On occasion, you will like the sparkle of a bright high-end, but you will find that vibrant trademark tiring on longer listening sessions. This isn’t an issue at all. These headphones provide a relaxed top end that never yells, never overpowers, and distracts.

The balance is nearly ideal to the ears, especially on more acoustic music, while it may be a little soft if you prefer electronic or hip hop music. We listen to everything, and instead of dominating the tonal balance, attention is constantly redirected to the mids, where vocals and so many instruments shine.

Sennheiser H660s Full Review

HD650 Vs HD660S
  • Dynamic speaker drivers with a diameter of 38 mm.
  • Frequency response ranges from 10Hz to 41kHz.
  • Resistance (ohms): 150
  • Sensitivity (decibels per volt): 104
  • Headphones with an open back and over-ear design.
  • Weight- 260gm.
  • THD+N = 0.04 percent
  • A detachable 3-meter cable with a 6.35-mm connector.

What Exactly Is In The Box?

The packing for the HD 660S is clearly on the more minimalistic side, but it does include almost everything you need to get started listening.

The HD 660S comes with two cables: one with a 14″ terminating and a 4.4mm balanced connector.

We are generally not to complain about cables, but we wanted to point out that the provided cords are quite lengthy (3m) and challenging to wrap up—they are pretty unruly. Finally, Sennheiser supplies a 14-inch to 3.5mm converter.

Sennheiser 660


The matte black finish appears to be intriguing. The HD660S and HD650 appear to be very comparable. They’re also incredibly well-built, with the drivers visible through a robust black metal grill.

These are some of the most durable headphones available, practically all Sennheiser products. Sennheiser would not have us believe otherwise.


Sennheiser created a new transducer for the HD660S, which they claim reduces harmonic distortion. As a result, the sound is more natural. A 38mm dynamic neodymium magnet driver is used in the driver.

Because the impedance has been reduced to 150 ohms, portable devices can now power the HD660S headphones. With the HD650, this was not possible.

The driver, transducer, and impedance all work together to create one of the greatest audiophile headphones on the market.


The HD660S headphones appear to grip very securely on the head and may feel a little unpleasant if used for long periods. The well-covered ear cups and headbands are comfy and help alleviate some of the stiffness.

A slight reduction in clamp force would have been a preferable alternative. Nonetheless, these are among the coziest headphones in this price range.

At high volume levels, open-back headphones do exhibit significant sound leaking. But this is fine because they are mostly intended for usage at home. If you listen to loud music for long periods, your ears will become less exhausted due to leaking.

Improved Airflow and Durability

Sennheiser 660

The steel mesh over the drivers is intended to provide greater ventilation for the drivers. Sennheiser claims that this gives them more control over air displacement. As a result, the music can breathe and flourish without overheating the drivers.

The padding on the earcups and the cables are both removable and replaceable if necessary. This means that you will be able to enjoy these headphones for many years to come.


The price may be a little out of reach for ordinary smartphone music users. However, it should satisfy audiophiles’ desire for high-quality sound.


The frequency response is relatively similar to the HD650. However, the HD660S has a somewhat more polished sound. When it comes to attack and delay, the HD660S sounds crisper and cleaner.

As with open-back headphones, the bass is not always as prominent as it is with closed-back headphones. If you want a more robust bass response, the HD660S might not be for you.

Clean And Robust

The bass is clean and robust, but not obnoxious. It depends on the familiarity of its predecessor to restore some of its strengths.


Fantastic work has been done here, with a fantastic balance created. The mid-range lacks a sense of harshness.

When the vocals and instruments find their mark, they sound rich and shine. Some engineers claim that the open-back headphone is less regulated here, but we disagree.

A highly detailed treble can be found in the high-frequency region. It is not sibilant, and it has a smooth yet unexceptional quality that provides just enough energy without being unpleasant. Sennheiser appears to have hit a home run here.


Sennheiser 660
Sennheiser 660

The HD660S excels in its great soundstage, similar to the fantastic HD800 to some extent. The stereo and spatial imaging provided by the Sennheiser HD range’s higher-end models is always superb, allowing you to delve deeper into musical arrangements.

Put on some of your favorite music, and the soundstage on these headphones will make you happy. You will notice the location of instruments and the richness in frequencies that you may have overlooked previously.

You also get two 3-meter interchangeable cables and an adaptor with the HD660S. The first cable has a big jack plug, while the second has a 4.4mm pentagonal connector.

Connection to mini-jack sockets is possible with the adaptor. All the connectors provided are gold-plated, which helps prevent long-term corrosion.

The headphones come in a beautiful black box with form-fitting foam and the Sennheiser emblem imprinted on top.

Here’s What Customers Want To Say!

Customer Reviews
Customer Reviews

According to an Expert on Reddit

“For me, it’s 650 > 660S.
Technically they’re all not that different, not enough to matter (while the 660S has different drivers, that doesn’t matter too much).

The 660S is related to the other two, but with less presence and even worse bass extension, we don’t get why it is the most expensive one. The 58X is the better deal if you want to go in that direction, even with import fees.

The 660S comes with a balanced cable which is not needed, all of them are fairly easy to drive.”

According to an owner on Amazon of both devices

“650 – the most natural midrange, the smoothest treble, the most intimate, but muddy, very muffled, the poorest imaging I’ve ever heard on an open-back headphone.

660S – the most detailed, excellent imaging, generally the most natural, but little muddy, little muffled, little metallic.”

Which Is The Best Option For You?

Which Is The Better One
Which Is The Better One

The difference in how you hear a song or music when it is played on speakers versus when it is played on headphones is significant enough to influence your opinion of the song or music.

The difference in detail is even more evident when it comes to the quality of the headphones you’re using.

If you have sensitive ears, you may be particularly picky when it comes to selecting the best headphones for your optimal sound experience.

Our story featured three characters, each with their distinct characteristics, some better than others.

Sennheiser’s HD 650 and HD 660S are both excellent members of the Sennheiser 600 series.

The HD 660S distinguishes out in terms of appearance, with its current and sophisticated matt black exterior. This model has also been enhanced, with several additional features added to make it even better than its predecessors.

If you have a restricted budget and are looking for headphones for everyday use, we would recommend the HD 650.

However, if you are a dedicated music enthusiast who is inspired to produce thumping and fashionable rhythms, the HD 660S is a must-have. You will not be disappointed while mixing sounds with its extensive features and flawless audio performance.

Is the Sony WH-1000XM3 still a decent choice?

Probably! While the Sony WH-1000XM3 is one of the best headsets available, its smaller brother, the Sony WH-XB900N, is a solid budget option that offers roughly 70% of the performance of these headphones for $100 less.

That isn’t a bad deal at all. If you’re on a tight budget, the WH-XB900N is the way to go.
The Sony WH-1000XM4 is among the best in its class for noise cancellation and isolation. If you were hoping for an improvement in noise cancellation with the WH-1000XM4, you’d be quite delighted with them. Sony’s team managed to make the ANC even better than before.

HD650 Vs HD660S FAQs


When was the HD 660S released?

Ans. The Sennheiser 660s were available for purchase on November 16th, 2017. It was, nevertheless, released on October 25th, 2017.

How many ohms does HD650 have?

Ans. The Sennheiser HD650 has a thumping 300-ohm impedance.

Where is the Sennheiser HD 650 manufactured?

Ans. Sennheiser has relocated HD650 production from Ireland to Romania.

I am looking for your feedback so do share them here. Cheers!

About the Author

HD650 Vs HD660S

Rach Wellard

Rach Wellard is the driving force behind Sound & Solitude. Her mission is to help you discover the profound impact of sound in your daily life and to explore the beauty of solitude. With a deep passion for the connection between soundscapes and emotions, she brings a unique blend of expertise and personal dedication to our platform.

Rach understands that every individual's auditory journey is unique, and she’s here to guide you every step of the way. As a devoted audiophile, Rach’s discerning ear carefully selects the most exceptional products that align with your desires for Sound or Solitude. In a world filled with noise and chaos, Sound & Solitude serves as your sanctuary.

Rach’s journey as an autistic individual with a heightened sensitivity to sound fuels our commitment to creating an inclusive space where everyone can find solace while enjoying the meaningful sounds in their lives. Her understanding of diverse sensory needs enables us to offer personalized recommendations and insights, ensuring that your chosen audio equipment not only meets technical criteria but also resonates with your unique sensory preferences. And if you simply seek the best sound possible, Rach has you covered.

At Sound & Solitude, authenticity is our foundation. We provide unbiased reviews and comparisons because you deserve nothing but the truth. Our reviews are meticulously crafted, drawing upon Rach’s deep understanding of audio technology and the human experience in the Sound and Solitude realms. Whether you're searching for noise-cancelling headphones to immerse yourself in music or seeking a gaming headset that transports you to virtual worlds, you can rely on our reviews and personally tested comparisons to find the best equipment for your specific needs. Explore our carefully curated content, from the latest wireless audio advancements to tips for creating your ideal auditory retreat.

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