Sennheiser HD600 vs HD650 vs HD660S: Review with Comparison

Headphones, perhaps, are one of the best inventions of humanity in the recent past. They offer the listener privacy and sounds of the utmost quality. In this post, we have included the Sennheiser HD600 vs HD650 vs HD660S comparison with detailed analysis.

Nowadays, most headphones come with a noise-cancelling feature, which is a feature way ahead of its time if you think about it. This feature also comes in handy If you prefer silence without any music.

Moreover, most headphones nowadays come with water, dust, and shock-resistant technologies, making them durable and portable.

The introduction of wireless headphones has intrigued many consumers who prefer its pocket size and wireless connectivity over its wired counterpart.

They can now be used for physical activities like jogging/runs, workouts, or dynamic gaming like Wii.

Nowadays, headphones also come with premium build quality and aesthetic designs to cater to the growing demand for customization.

Therefore, it is not surprising that different headphone brands constantly come out with new products now and then.

Sennheiser has opened the way to the top of the sound chain with their cutting-edge headphones that are unrivalled in efficiency and even aesthetics.

The German giants have been one of the pioneers in the audio industry and take pride in the quality and durability, which vary from earphones & headphones to speakers & soundbars.

Established in 1945, Fritz Sennheiser used his vast expertise and skills from his previous scientific profession to cater to the growing demand of the measuring devices and microphones market.

Initially, the company used to manufacture only measuring instruments which were bought by Siemens.

First, let us talk about the Sennheiser HD600.

Sennheiser HD600

Sennheiser HD600


Key Highlights

  • Open metal mesh grilles
  • Lightweight aluminum voice coils
  • Maintain optimum sensitivity and excellent dynamics

The HD 600 is catered for the music professional since it is designed for maximum clarity.

Moreover, even 20 years after its publication, it is still widely regarded as the gold standard for critical hearing in scientific and hi-fi environments as a tool of Sennheiser’s desire for great sound.

The HD 600 was designed to provide developers and audiophiles with an unbiased overview of everything before the sound series.

The HD 600 is the universal standard headphone for comparing mixes, masters, and even other audio materials, as it was designed to disappear when the user clicks play.

The backbone of the HD 600 transducer unit is an acoustically precise open-back earcup that allows each audio wave to propagate freely—a Sennheiser invention invented and mastered for the most realistic personal listening experience.

Thanks to specialised acoustic silk that governs airflow, audio from the unique 42mm driver is clear of vibration and distortion.

Key Highlights

The 38mm diaphragm, which uses superlight aluminium voice coils, has quick rest and reaction times for clinical information that never sounds abrupt or hyped.

This blend of driver size and authenticity provides an articulate response that is true to the origin across the full audible range of sound—the kind of hearing experience needed to consume the information with confidence.

The HD 600’s 300-ohm impedance creates a unified background that encourages the complexities of your designs to jump ahead like never before. 

Every transducer is evaluated against strict criteria for consistent output over the complete frequency spectrum in both channels.

The HD600 produces exceptional sound regardless of room acoustics or loudspeaker placement by limiting variances among left and right channels.

For prolonged hearing sessions, the velour HD 600 cushion is soft to the fingertips.

Indeed, the earcup grille design was designed especially for this transducer device, ensuring a high-quality personal audio experience.

The HD 600 is built in a truly exceptional manufacturing plant in Ireland, with the care and attention to the precision needed to accommodate a wide range of acoustic materials.

The HD 600 experience is reliable around the world, regardless of where it was bought. The resonators, for example, have stainless steel mesh to ensure consistent efficiency after processing. 

The majority of the HD 600’scomponents are interchangeable, allowing it a breeze to keep running as your go-to reference display irrespective of the acoustics of your hearing space.

A removable, impedance-matched cable with incredibly low capacitance is included with the HD 600.

The primary quarter-inch stereo connector is used to connect gadgets like headphone amplifiers and A/V receivers, digital audio consoles, analogue gear etc.

Its length of 9.8 feet allows for free listening on gear hidden deep inside your shelves, studio, or laptop.

A high-quality converter is provided to convert the 6.3mm to 3.5mm / 18-inch for use with a wide range of other audio equipment.

Now, let us talk about the Sennheiser HD650.

Sennheiser HD650

Sennheiser HD650


Key Highlights

  • High-quality titanium finish
  • Improved frequency response
  • Highly optimised magnet systems

The HD 650 is a benchmark for absolute sound immersion, accurately producing intricate details as well as the highlights of your songs.

It is the headphone to look for when the sound matters most,  customized for hours of tireless hearing.

The HD650 has an excellent finish with precise acoustics and a premium build.

It is an open-back headphone that can be used by professionals in the music industry who possess an in-depth knowledge of music and are critical listeners of sound.

The HD 650 is an immediate improvement for audio recording, mixing, mastering, and critical hearing.

The greatest components work at their best when nothing obstructs them, as audio professionals know.

It is no wonder that the HD 650 has a seamless response and dimensional soundstage—the open earcups give every individual audio wave plenty of space to extend as they will in reality.

A 38mm diaphragm with an aluminium voice coil is used in the 42mm transducer, primarily configured for extended, critical listening.

The general treble and low-frequency effect are seamless, whilst the midrange is replicated with lifelike composure—nothing is sacrificed in the process.

The HD 650’s ability to uncover intricate details without over-hyping the treble range is especially beneficial to newer high-resolution sample rates.

Each transducer is tested to strict standards and matched with a perfect fit to ensure that the entire frequency range is represented consistently in both channels.

Key Highlights

The HD 650 was designed to give more information, rhythm, and more monitoring time.

The HD 650 blends the finest of advanced transducer engineering with an eye for detail needed to accommodate a wide range of acoustic materials.

It is manufactured in Ireland at an exceptional manufacturing  plant.

Our manufacturing thresholds are fairly tight, guaranteeing that your HD 650 experience matches that of others around the world, regardless of where it was bought.

The resonators, for example, have stainless steel mesh to ensure consistent efficiency after processing.

The majority of the HD 650’s components are interchangeable, making it a breeze to keep running as your go-to comparison tracking solution.

The velour pads and the earcup grille pattern were engineered to ensure a surreal musical experience.

A removable, impedance-matched cable with incredibly low capacitance is included with the HD 600.

The primary quarter-inch stereo connector connects gadgets like headphone amplifiers and A/V receivers, digital audio consoles, analogue gear etc.

Its length of 9.8 feet allows for free listening on gear hidden deep inside your shelves, studio, or laptop.

A high-quality converter is provided to convert the quarter-inch cable to an 18-inch for use with a wide range of other audio equipment.

Now let us talk about the Sennheiser HD660s.

Sennheiser HD660s

Sennheiser HD660s


Key Highlights

  • High conductive OFC copper
  • 150 ohm nominal impedance
  • Frequency response 10 to 41,000 Hz

The HD 660S is a versatile open-back headphone with the flexibility to bring your music library. It’s the ultimate combination of durability and beauty.

HD 660S predecessors HD 650 and HD 600 broke performance boundaries in the audiophile headphone genre with their charismatic signatures and liquid-smooth reaction.

Except at the extremes of the frequency range, the HD 660S surpasses the finest of that historic DNA with incredible speed and perfect instrument replication.

The HD 660S provides the clear, tack-sharp clarity audiophiles desire without losing the entertaining dynamics that make music so exciting, thanks to an all-new transducer and carefully ventilated drive set.

You will appreciate why the HD 660S is so exceptional after only one listening. Its function has become much clearer after hundreds of listening sessions.

The outcome of an open-back earcup hooked up to a new transducer optimized for the typical audiophile is what you experience every moment. Its quick response is ideal for confidently producing such frequency-stretching tracks.

The 38mm diaphragm stays dynamic for rapid impulse precision around the board due to an aluminium voice coil.

This activation and rest-activity explicitly unlock the capability to convey tonal and spatial characteristics.

The steel mesh on the HD 660S drive unit is eye-catching in appearance but much more spectacular in terms of results.

It finishes the ventilated driver by providing clear air displacement power to minimise turbulence.

Consequently, diaphragm travel is pure, allowing the music—and only the music—to glow with perfect integrity and voice.

Because of the steel structure, output tolerances can be even more refined, resulting in surprisingly stable HD 660S characteristics.

The audio from each transducer is free to extend when paired with the open-back ear cups, precisely as it would in reality.

Key Highlights

The HD 660S is the ideal companion for amplifiers, A/V receivers, and audio interfaces, with a 150-ohm impedance and a magnet that is more efficient than its contemporaries, making it easy to drive irrespective of how your layout varies over time.

The HD 660S is designed for performance on a broader range of platforms to satisfy the differing amounts of power available in output amplification circuitry.

The audiophile of today has more component options than ever before.

Every HD 660S designed has gone through a matching process to ensure that each transducer is matched to its opposite-channel counterpart in their Ireland production plant.

These tolerances are incredibly tight, and when combined with automatic assembly systems, ensure that the HD 660S experience matches that of those around the world.

Without compromising the longevity needed for everyday use, it is built with careful, lightweight materials invisible to the hearing device.

With so much music to listen to, we needed each touchpoint to be gentle, premium, and long-lasting for those long listening sessions.

The HD 660S comes with a package of critical cables that are all impedance-matched and have very low capacitance.

The audiophile-standard quarter-inch stereo connector connects to products like headphone amplifiers and A/V receivers, digital audio players, computer-based workstations, analogue gear, and more.

A compatible 4.4mm connector provides access to a new range of balanced output devices that value the lightweight plug’s long-term reliability.

When paired to balanced source circuit outputs, a balanced headphone rig provides an even reduced noise floor and more excellent dynamic range.

As a result, the audience can hear a larger soundstage, tighter transients, and unimaginably simple instrument isolation.

Each cable is 9.8 feet long to allow for free listening on gear hidden deep within your shelves, studio, or laptop, and it comes with a versatile converter to convert the 6.3mm to 3.5mm connector.

Sennheiser HD600 vs HD650 vs HD660S – Features & Specs

FeaturesHD 600HD 650HD 660S
Ear couplingOver-earOver-earOver-ear
Weight (g)260260260
TransducerDynamic, openDynamic, openDynamic, open
Minimum Frequency response (Hz)121010
Maximum Frequency response (KHz)40.539.540
Nominal Impedance (Ohm)300300150
Sensitivity (dB)97103104
Maximum power handling (mW)200500500
Total harmonic distortionLess than 0.01%Less than 0.05%Less than 0.04%

To better understand some of the products’ specifications and what they mean, I will try to break them down for you below.

What is sensitivity? and how does in influence the performance of these headphones?

The sensitivity of a speaker refers to how often it transforms an electrical signal into an acoustic signal.

Typically, the sensitivity is measured in decibels of sound pressure level per milliwatt.

The speaker’s sensitivity determines how loud they can be at a given volume level from the source.

In this specific case, all the Sennheiser headphones have different sensitivity values, with the HD600 possessing the least, whilst the HD650 and the HD660S include much more significant values.

Therefore, both the HD650 and HD660s are much louder than the HD600.

What is Frequency Response ?

The frequency-specific sensitivity of the output is referred to as speaker frequency response.

The frequency responses demonstrate the spectrum of frequencies that speakers can reproduce.

The optimal frequency range is 20 Hz to 20 kHz, which is the audible sound range.

In this specific case, both the HD650 and HD660s are much better than its counterpart, the HD600 as it covers a wider frequency range between 10Hz-40/40.5Khz.

What is Nominal impedance ?

Impedance is the resistance to current flow. The lower the impedance, the less current flowed.

Impedance is expressed in Ohms, which is denoted by the Greek letter Omega (Ω). Earphones, headphones, and speakers have resistances ranging from 8 Ohms to 600 Ohms or more.

In this specific case, both the HD600 and HD650 have the same Nominal Impedance of 300 Ohms.

Whereas the HD660s has a Nominal Impedance of 150 Ohms.

What is Total Harmonic Distortion (THD) ?

Total Harmonic Distortion is the difference between the actual signal and all the distortion products in the audible range.

The lower the THD, the less distortion there is, and hence the higher the accuracy.

The unit of the THD is usually depicted by either a percentage (%) or decibel (dB).

In this specific case, the HD600 offers the most minor distortion and the most precise audio output.

Most of the other specifications are self-explanatory and can be easily understood.

The specifications mentioned above are not unique to headphones but also for headphones.

Verdict – Sennheiser HD600 Vs HD650 Vs HD660S

The disparity between how you listen to music when it is playing on speakers as opposed to playing on headphones is significant enough to influence your preference for the music.

The variation of detail is much more noticeable when it comes to the nature of your headphones.

If you have sensitive hearing, you should be picky when selecting the best headphones for the best listening experience.

Sennheiser’s 600 series includes the HD 600, HD 650, and HD 660S, all excellent headphones.

First, we must understand that this is a callous choice to consider these three headphones offer exquisite features at different price points.

With its futuristic and elegant matt black exterior, the HD 660S is miles ahead of its counterparts regarding style and build quality.

The HD660s have also been enhanced with several innovative features to make them much more significant than their counterparts.

If you are on a tight budget and want to buy headphones for daily use, you could opt for the Sennheiser HD650.

Perhaps the fascinating feature of these headphones is their versatility. It can play various music across multiple genres from rock, R&B to Hip-Hop and jazz.

However, out of the three models, it probably offers the worst treble and bass.

Additionally, as per many users, it is not the most durable model and can deteriorate over time.

That being said, if you are a music lover who is driven to make pulsing and funky music, the HD 660S should be your first choice.

You need not be upset when mixing your music, thanks to its sophisticated functionality and excellent audio efficiency.

Ending Thoughts On Sennheiser HD600 Vs HD650 Vs HD660S

The HD660s boasts an exemplary soundstage that is second to none.

Although it Is the most expensive out of the 3 models, it does complete justice to its price.

Finally, each model racks up decent reviews ad ratings on Amazon. The HD600 has a 4.8/5-star rating as rated by 1527 customers.

The HD650 has a 4.7/5-star rating as rated by 1915 customers, and the HD660s has a 4.8/5-star rating as rated by 583 people.

Therefore, there is not a lot separating the three. They offer almost the same features but at different price points.

All three headphones weigh the same and have the same dynamic, open transducer.

I hope this article will help you make a more conscious decision now that you know the differences between the three headphones and their respective pros and cons.

It can be a tricky decision, but it should be effortless if you have set a budget in mind.

If you have more money to spend and can afford the HD660s go for it.

It is one of the latest Sennheiser models, but it offers sound qualities that are par with the industries best.

Let us know your views about the Sennheiser HD600 vs HD650 vs HD660S in the comment section.

Check our recent posts on headphones, earphones, soundbars and speakers.

Leave a Comment