Sennheiser HD600 vs HD650 vs HD660S: Review and Comparison

Who does not love putting on their headphones and grooving to their favorite music while blocking out the rest of the world?

I know I do!

I also know that if you want the absolute perfect musical experience to really get into the mood, you are really going to need some premium headphones.

After all, cheap and low-quality headphones will not offer the same audio experience as high-quality ones. Moreover, you will be amazed if you compare how the details sound when you’re listening to music using a lower quality headphone versus a higher quality headphone.

When it comes to premium sound experience, Sennheisers have it all. Throughout the years, Sennheiser has really left a mark in the musical market with its outstanding products.

This article is all going to be about headphones. Most importantly, three outstanding headphones that are produced by the famous Sennheiser audio company.

Today we are going to tell a tale of three Sennheisers- The HD 600, HD 650, and the HD 660S.

All about Sennheiser

Sennheiser electronic GmbH & Co. KG is a German audio company that was formed in 1945 by the German inventor and entrepreneur Dr. Fritz Sennheiser.

Sennheiser consists of two independent units: the consumer division and professional audio division. Whilst the consumer division produces a wide variety of headphones and home entertainment gadgets for consumers, the professional audio division is more centered towards the manufacture of audio devices required for business presentations, conferences, and the educational sector.

The company has earned its fame for its specialization in the design and production of high-quality microphones, headphones, headsets, and telephone accessories.  With its prolonged exhibition of excellence, Sennheiser has achieved respectable awards such as the Audio Engineering Society’s gold medal in 2002 and the Primetime Emmy Engineering Award in 2013.

To this day, Sennheiser electronic is widely recognized and appreciated for their innovative technology, exclusive craftsmanship, and praiseworthy quality audio products.

The HD 600, HD 650, and HD 660S compared at a glance

Before we can further go into the details of each of the headphones, let us first compare them. You would want to know the specifications and features of these headphones before you can pick the right one for you. We have, therefore, created a comparison table for your convenience. You can go through the table to understand the similarities and differences at a glance.

FeaturesHD 600HD 650HD 660S
Ear couplingOver-ear (circumaural)Over-ear (circumaural)Over-ear (circumaural)
Weight260 gram260 gram260 gram
TransducerDynamic, openDynamic, openDynamic, open
FeaturesHD 600HD 650HD 660S
Frequency response12-40500 Hz10-39500 Hz10-41000 Hz
Impedance300 Ohms300 Ohms150 Ohms
Sensitivity97 dB103 dB104 dB
Maximum power handling200 mega Watt500 mega Watt500 mega Watt
Total harmonic distortion<0.01%<0.05%<0.04%

As you can see from the table above, all three of the headphones are over-ear, also known as circumaural open-back headphones. The three Sennheisers are quite lightweight compared to other heavily build headphones, each weighing about 260 grams. The transducer principle that these headphones follow is dynamic and open.

However, when we look at the differences we can see that each one has its individual features. In terms of frequency response, the HD  600S and HD 660S has a wider range compared to the HD 650. Whilst both the HD 600 and HD 650 provide an impedance of 300 Ohms, the HD 660S offers a lower impedance of 150 Ohms. In terms of sensitivity, HD 660S works better. When it comes to maximum power handling, we can certainly say that the HD 600 requires some work.

Now that you have got a glimpse of the differences, let’s dig right into the details.

The HD 600

The HD 600 is an audiophile-friendly high-quality professional stereo headphone. These remarkable headphones not only provide dynamic audio performance but are also extremely comfortable to use.


Weight260 g
Frequency Response12-40500 Hz
Maximum power handling200 mega Watt
Impedance300 Ohms
Sensitivity97 dB
Total harmonic distortion<0.04%

Built and design

The circumaural HD 600 is composed of plastic and gives out a nineties vibe with its steel blue marble exterior. When we hear the word plastic, we often imagine it to be cheap. However, the quality of the plastics used in this headphone is premium, unlike other headphones available in the market.

Weighting about 260 grams, the headphone is quite light and comfortable to use. Although it is lightweight, the build is robust and sturdy.

The headband has four pieces of thick foam that are about 1.5 cm. The headband can be adjusted to accommodate different head sizes. The earpads are composed of cozy velour material wrapped around foam. The plush foam of the oval ear pads is around 2.5 mm and provides great comfort to the ears. These ear pads can easily be replaced and restored if they wear off.

Now let us look at the cool features that these magnificent headphones have to offer.

The enclosure of the driver is covered with a premium quality metal mesh grill. This design feature allows the transparent and clear sound. Although the external grills can be twisted if pressure is applied, they are easily replaceable.

The driver uses a neodymium ferrous magnet, which helps to increase the sensitivity of sound and ensures dynamic bass response.

The HD 600 uses a duofol two-layer diaphragm which provides the function of minimizing distortion of sound. This technology works by reducing standing waves and cutting down surface born resonance.

The headphone is connected with a lead cable which has rigid, detachable plugs at the bottom of each earpiece. The detachable oxygen-free copper cable is three meters in length. These cables are much better than the coiled cables since there is less chance of it getting tangled.

Sound quality

According to Sennheiser, HD 600 provides “exceptionally natural, spatial, and accurate sound.”

These powerful headphones have a whopping 300-ohm impedance, which is way higher than your usual headphones that offer an impedance of 50 ohms. This provides the advantage of your headphones being able to handle higher degrees of amplification.

Now let’s look at the bass. I would have to say that the bass has decent quality. If the bass end has to be described, it sounds accurate and tight. On the other hand, the midrange feels detailed and natural. The high end sounds spacious and airy.

When we played some rock tunes to test the headphones, the music felt accurately dynamic. On the other hand, classical music sounded very detailed and smooth.  Hence it is an ideal device for listening, mixing, and instrumental music.

We noticed that all frequencies are beautifully balanced and the sound does not overpower each other. It is safe to say that the headphones offer excellent tonal balance.

Overall these headphones sound wide, open, and very detailed.

Why pick HD 600?

Great comfort

The headphones are convenient to handle and do not cause much discomfort as they can be adjusted according to the size of the head.

Neutral and accurate sound response

The audio response is extremely natural. Instrument separation in music is extremely accurate when it comes to the soundstage.

Extremely durable

The parts can be removed and repaired. So if one of the parts of the headphone is damaged, it can easily be replaced.

What can be improved?

Although the HD 600 provides exceptional audio performance, there are some areas of improvement, in my opinion.

Firstly, the stock cables are too thin and can easily be defective. The earpads, although quite comfortable, will eventually wear out with intensive use.

One thing that you should keep in mind that sub-bass is not present. So you might have to buy a subwoofer if you need extra bass.

Since the headphones have a high impedance, they will particularly be fit for high-end amplification. So you will need high-quality amplifiers to get the perfect result. If you plug it into your phone, the performance of the headphone may not be exemplary.

The HD 650

If you’re looking for headphones that are not only durable and comfortable but that also provide warm, smooth sound with deeper bass, the HD 650 offered by Sennheiser should be your first, and perhaps the only choice!


Weight260 g
Frequency Response10-39500 Hz
Maximum power handling500 mega Watt
Impedance300 Ohms
Sensitivity103 dB
Total harmonic distortion<0.05%

Built and design

The HD 650 is quite elegant when compared to its previous model. It is designed to include a greyish metal exterior combined with black padding on the interior. The outside of the ear cup is enclosed with metal borders. Overall, the high-quality titanium finish makes these headphones premium in terms of design. The exterior is mostly plastic but it works pretty well.

The elliptically designed ear cups are foam covered and provide a fuzzy feeling when worn. They are large and the ear pads fit the ears comfortably, without putting too much pressure on the ears.  The quality velour padding is designed to ensure that the ears do not touch the driver, making it comfortable to use for a long time.

The headphones are built with a developed damping element. This is composed of fine acoustic metal mesh. This feature ensures constant and precise damping over the entire diaphragm surface. Thus it provides uniform attenuation over the entire area.

Thanks to the exceptionally lightweight aluminum voice coils, you will get to experience outstanding transient sound response. The driver consists of magnet systems that are highly optimized for minimum harmonic distortion.

Just like the HD 600, the HD 650 also comes with a detachable oxygen-free copper cable. This Kevlar reinforced cable is built to ensure very low handling noise. These exceptional headphones can be directly connected to high-quality components such as CD players, DVD-A, and SACD.

To summarize, the HD 600 is the epitome of comfortable, premium quality and robust design.

Sound quality

Smooth, clean, and accurate are three words that can perfectly describe the audio performance offered by the fantastic HD 650 headphones.

The sound is very clear and vivid when you listen to music using these headphones. The natural tonality of these headphones are a pure delight to the ears. It also offers a pretty bright top-end.

The texture of the bass feels pretty solid, so fine textures hidden behind the bass will be revealed on using these headphones. When the headphones were tested with tracks that included bass guitar, details of the bass response were impressive. The fluid midrange is great and quite straightforward.

The soundstage is quite intimate, rather than wide and spacious. Hence classical compositions and rock ballads sound better compared to metal and EDM. The soundstage does wonders with a live recording.

Overall the sound is quite dynamic and punchy without being too aggressive. With its amazing transparency and powerful dynamics, the HD 650 do not disappoint in terms of audio quality.

 Why pick HD 650?

Great sound performance

The HD 650 is top quality, hi-fi dynamic stereo headphones. These headphones provide boosted lows without harsh high frequencies.


The headphones are extremely versatile. It handles a wide range of genres. You can enjoy moving to the beats of rock and hip-hop or just relax to the acoustic sounds of instrumental and classical.

Light and comfortable

The HD 650 is quite comfortable to use with their effectively-designed earpieces. You can wear them for a long time without noticing that they are surrounding your head and covering your ears.

What are the drawbacks?

The problems associated with these headphones are mainly based on how they are designed. First of all, because they are open-back headphones there is sound coming from the back. The durability of these headphones requires improvement according to many users.

Now, let’s talk about the sound. What is missing?

There is no denial in the fact that these headphones provide excellent audio performance. But in my opinion, there is room for improvement.

The first thing that should be considered is that the headphones can be too smooth sometimes. This means that they can get a little duller compared to other headphones.

If you’re a bass head or a treble head, these headphones may be too laid back for you. There can definitely be some improvements made for the treble and the bass.

The headphones are a little bit pricey- so we advise you to test them first before getting them.

Find out which one is more suitable for game

The HD 660S

The new HD 660S is the perfect fit for you if you’re looking for a sophisticated audiophile experience. It offers everything that is missing for your ordinary headphones: crisp bass, natural treble, high-end comfort, and supreme connectivity.


Weight260 g
Frequency Response10-41000 Hz
Maximum power handling500 mega Watt
Impedance150 Ohms
Sensitivity104 dB
Total harmonic distortion<0.01%

Built and design

The HD 660S took a more contemporary turn in design compared to its vintage predecessors. It’s the perfect combination of timeless elegance and contemporary style. These classy looking headphones provide just the right aesthetics to lure you in. It’s matt black exterior is extremely stylish, and it can be matched with any outfit you wear. So you’d definitely want to show off these magnificent headphones.

Just focusing on the design won’t do justice to the manufacturers of the HD 660S. The impeccable level of craftsmanship that has gone into the making of these aesthetic headphones definitely has to be appreciated.

HD 660S is quite sturdy and incredibly light because of its plastic composition. So the convenience of use is a big plus for these headphones.

The massive perforated ear cups look even cooler than before in the HD 660S. The earpads are made of fairly dense foam and wrapped in velour. This feels soft to the ears and makes the headphones comfortable to wear. The shape of the elliptical ear cups is designed in such a way that they follow the human ear anatomy.

So what’s new about the features?

The HD 660S comes with a brand new cutting edge Sennheiser technology. It features a new transducer design which is aimed at delivering low harmonic distortion. This feature includes a stainless steel fabric that is adapted to improve the movement of the diaphragm. The lightweight aluminum voice coils have been improved to be fasting reacting.

The supreme connectivity offered by these headphones is also a plus point for the user. You can have a wide range of cables for any occasion. The cables are made of conductive oxygen-free copper cable which provides sturdy par aramid reinforcement.

Overall, the design of the HD 660S has been improved such that it provides lower distortion, improved bass, and treble response, greater spatial imaging, and better impulsivity.

Sound quality

The HD 660S surely surpasses its predecessor, the HD 650, with its exceptional audio performance. With its smooth tones and rich sound, the HD 660S are wonderfully designed to provide you the best audio experience you can ask for.

The headphones have an excellent, wide sound stage. Thanks to its expansive stereo and spatial imaging, your ears will get to explore sounds in ways it has never explored before!

First, let’s talk about the bass. These headphones provide a dynamic and articulate bass response. The upper midrange is extremely smooth and overall, the mids are exceptionally clear and natural sounding. The highs feel bright and warm and are very pleasing to the ears.

The treble on the other hand is very energetic and bright sounding. The HD 660S has an extended and well-balanced frequency response which is meticulously expressive.

Why pick HD 660?

Dynamic and involving

The audio experience that you will get when you put on these headphones is nothing short of dynamic.

Comfortable to use

The best thing about the headphones produced by the Sennheisers is the comfort that you get while using them.

Spectacular soundstage

The HD 660S offers a wide, expansive, and spectacular soundstage with outstanding spatial and stereo imaging.

Sophisticated design

The classy headphones not only win in the construction and build but also in the outlook. The aesthetic design of these headphones is very sophisticated.

In what ways can the HD 660S be improved?

The spectacular, sophisticated, and dynamic HD 660S has many outstanding features that make it stand out from the rest of the headphones available in the market. Although its performance and outlook are better than its predecessor, there are a few areas of improvement that we are willing to point out.

The HD 660S has an impressive neutral bass response. However, if you want to listen to more upbeat rock and metal music then you could definitely use more bass. There is also a slight distortion on the sub and mid-bass, so you should look out for that.

The headphones are also not very portable and are mainly used for desktop usage.

Which one is the best pick for you?

The difference between how you hear a song/music when it is played on the speakers versus when it is played on the headphones is large enough to determine your liking of the song/music.

The difference in detail is even more significant to the quality of the headphones you are using.

If you have sensitive ears, chances are that you might be very picky about choosing the perfect headphones for your optimum sound experience.

Our tale had three characters- each with their individual features, some better than the others.

The HD 600, HD 650 and HD 660S are all outstanding members of the Sennheiser 600 series.

When it comes to design, the HD 660S definitely stands out with its contemporary and classy matt black exterior. This model has also been improved and a lot of new features have been added to make it even better than its predecessors.

Now if you’re someone who has a limited budget and is looking for headphones for everyday use, I would suggest that you go for HD 600 or HD 650.

However, if you’re a passionate music enthusiast who is inspired to create pumping and trendy beats, you should definitely choose the HD 660S. With its advanced features and impeccable audio performance, you will surely not be disappointed when you mix your sounds.

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