When it comes to reproduction of sound naturally, open back headphones are mostly credited as the best. Open back headphones also give out better soundstage experience and immersive audio reproduction. If you are planning to jump on the open back train, you should check this out – we have rounded up a list of the most exciting best open back headphones, as well as offering you some solid buying advice.
- Focal Clear – Best Open-back headphone
- Audeze LCD 2 Classics
- HiFiMAN HE 400S
- Sennheiser HD 600
- Koss Porta Pro
- Philips X2/27 Fidelio
- HiFiMAN Sundara
- Shure SRH 1440
- Beyerdynamic DT 990 PRO
- Grado SR60i
|Focal Clear||55 ohms||Dynamic||40mm||104 dB|
|Audeze LCD 2 Classic||70 ohms||Planar Magnetic||106mm||130 dB|
|Hifiman HE400S||22 ohms||Planar Magnetic||60mm||95 dB|
|Sennheiser HD 600||300 ohms||Dynamic||40mm||97 dB|
|Koss Porta Pro||60 ohms||Dynamic||Unknown||101 dB|
|Philips X2/27 Fidelio||30 ohms||Dynamic||50mm||100 dB|
|HIFIMAN SUNDARA||37 ohms||Planar Magnetic||60mm||94 dB|
|Shure SRH1440||37 ohms||Dynamic||40mm||101 dB|
|Beyerdynamic DT 990 PRO||250 ohms||Dynamic||40mm||96 dB|
|Grado SR60i||32 ohms||Dynamic||Unknown||98 dB|
1. Focal Clear – Our Best Open-Back Headphone
Driver size: 40mm
PROS: clear sound, better built quality
CONS: nothing much
If you are looking for a high-end build headphone, then this is the best choice you can come across. Focal as a company has been a renowned world-class producer of speakers over the years. When the company first ventured into the headphone market in 2012, Focal’s mission was to provide exclusive technology and better audio performance compared to other players in the market.
The Focal Clear is an over-ear, open back, dynamic headphone. The headphone comes with the design of its predecessors the Elear and Utopia but with a few tweaks. The headband is covered by gray leather, the earpads are made of memory foam and feature a perforated design. The yokes are aluminum made while the outer earpad covers are stainless steel mesh.
Like both the Elear and Utopia, the Focal clear is a very comfortable headphone. Memory foam padded earpads and its industry-leading built quality make it one of the comfortable headphone in the market. The pads are removable, and you can get replacements through your dealer or Amazon.
When it comes down to accessorization, The Focal Clear beats the Elear and Utopia hands down. It includes a 1/8″ jack to 1/4″ stereo jack adapter, a beautiful fabric covered case and a number of cables. The cables are; a 3m XLR 4-pin balanced cable, 3m 1/4″ TRS jack unbalanced cable and a 1.2m 1/8″ TRS jack unbalanced cable.
For the sound, We can categorize the Focal Clear as a very clear and balanced headphone. It is not perfect but overall it is very close. The bass response is not the tightest we have heard but being an open-back can, the standard is excellent. Compared to the utopia, the midrange is good, and it also features a good treble realism.
Overall the Clear is a comfortable headphone, more accessorized and has one of the best tonal and sound balance. The only downside we could point out would be the weight of the headphone, but given the comfort of the headphone, you can easily forgive such setbacks.
2. Audeze LCD 2 Classic – Runners Up
Driver size: 106mm
PROS: comfortable design, better build quality
CONS: bulky nature lacks accessories
The Audeze’s LCD series is one that includes some of the best headphones money can buy. The LCD series currently features ten headphones with the LCD2 Classic (LCD2C) being the cheapest among the list. The LCD2C features most of the LCD2 design with changes in the overall weight, construction materials, and the price.
The first thing we noticed when we got these headphones was the quality of materials and the build quality. The headband and earpads are covered by a very high-quality faux leather. The earpads are memory foam padded to provide better comfort and conform to your ears to give quite a good seal.
Like most othordynamic headphones, the LCD2C is on the heavy side. Though this might be a disadvantage of having this can, the comfort of the pads easily offsets their weight, and you can have them for more extended listening sessions. With the capsule housing design, the wood rings are not included with the LCD2C. Instead, the housing is made of crystal infused nylon that looks and feels durable and extremely hard. Unlike the wooden cups that tended to weaken and crack over time, these new housings seem more strong.
No case or adapters are included in the package. This was a surprise to me although you can use the packaging it comes in as a storage case. However with the LCD line travel case retailing at $125, which would, in turn, make the headphones and the case at over $900. This seems unrealistic especially if you also need to buy the travel case.
As with the sound, the bass is tight while the midrange is neutral. The treble is well extended. We am sure most people will like this tonal character. The LCD2C has higher clarity; listening to it at very high volumes you hardly notice any distortions.
To sum up, We would say the LCD2C is a good headphone with lots of features to admire. The build quality and materials are no doubt top notch. The lack of accessories is one problem considering this was an affordable LCD that was set to retail at only $599. The sound is on par, and the bass response is quite good.
3. HiFiMAN HE400S – A Superb Budget Open Planar Headphone
Driver size: 60mm
PROS: Cheaper, best midrange
CONS: Lacks low bass, looks flimsy and would require you to be carefull with them
If you are looking for a cheap open back circumaural (around the ear) headphone that is sure to deliver good sound quality, then this HiFiMAN headphone is a solid choice.
The HiFiMAN HE400S is a full size planar magnetic headphone that priced well for an entry headphone. The HE400S features large circular earpads prominent with the HE’s line of headphones. The earpads are quite comfortable to allow for extended listening hours. However, the headphone does not fit larger heads and will require some adjustments and strategic placement if you fall into this category.
For an orthordynamic headphone, the HE400S is a light headphone. Weighing at only 348grams, the HE400S is the lightest headphone in the HiFiMAN HE series. The build quality of the HE400S is nothing to get excited about. The headband arch is plastic, and the pad made of pleather. For this reason, you should be careful when using these headphones or storing them when not in use avoid destruction. The color is also plain, but the finish is quite good.
Unlike our top open back headphone, the HE400S lack accessories. No travel pouch but comes with a long cable and a 3.5mm to 1/4″ adapter. For indoor use, this headphone would be ideal.
What the HE400S lacks in design and build quality it makes up in its sound. Comparing it to some of the best audiophile headphones, We would say the HE400S is a fabulous sounding headphone. Starting off from a negative point the HE400S lacks weight in the low range notes of bass. For bass lovers, we would recommend the Phillips Fidelio X2 or the Hifiman Sundara that feature in this list. we have learned that changing the earpads of the HE400S could lead to an improved bass response. we am yet to try it but, we will post an update once done. The mid-range of this headphone is without a doubt just great! It comes with a few flaws here and there, but those are easily forgiven. The treble has a slightly laid back response.
For audiophiles looking for a better bargain, the HE400S is that headphone. It comes with flaws but not deal-breakers. The low bass is quite lacking, but they do a very great job of giving out a balanced vocal reproduction.
4. Sennheiser HD 600 – Budget Open Back Headphone
Driver size: 40mm
PROS: Natural and Smooth Sounding, comfortable
CONS: Needs an amp to get the best out of them
The Sennheiser HD600 has been one of the most respected headphones on the market for nearly two decades. When it comes to hi-fi sound, there are more expensive headphones out there, but, at the current price, the Sennheiser HD 600 remains one of the best affordable audiophile grade headphones buys today in the market.
Before going further with this review, we would love to urge anyone looking to purchase the HD 600 to get a proper amplifier to match them. Using them out of a mobile device, laptop or PC would not bring out their full potential.
Now over to the review,
First, we must say the HD600 is a well-constructed headphone. we have owned ours for five years now! And there are also people out there who have had theirs for a decade or more. The headphone is made mostly from plastic but seems to be of higher quality. The plastic surrounds the ear cups and is also used for the headband. The earpads are made of a very comfortable and cool velour material padded with memory foam. These can be easily be replaced over time as the need arises. The grills are made of metal. The headband can adjust to fit most average sized heads. It is comfy and well padded. The clamping force at first was powerful, but as time passed the metal hinges stretched and the headphone became even more comfortable.
The HD600 is best known for its neutrality and fantastic sound quality. With the bass, we would say this headphone has plenty of tight and punchy bass. The sub bass is however not as good, but overall it is well proportioned. The HD600 excels at the midrange; we think we have heard very few headphones that can compare to these levels of mids quality. The Highs of the HD600 and other Sennheiser models have been a point of controversy among audiophiles. Most claim they have a ‘veiled treble,’ but honestly, we find the detail of the Sennheiser HD600 to be quite good, maybe rolled off a bit.
We Love these headphones. Everything from the built quality to the comfort and the sound quality is just great. At their current price, or even more than the amount you will undoubtedly get a set of amazing headphones…read our in-depth review.
5. Koss Porta Pro – Our Cheapest Open Back Headphone Pick
Driver size: Unknown
PROS: Cheaper priced, better sound
CONS: At the price, nothing negative about to point out
For over three decades, Koss has been producing the Koss Porta Pro in the headphone market. Though these were not our first classic headphones, they pretty much ended up being among the best of our hi-fi gear.
If you are looking for the looks in a headphone, then, this might be the last place you would turn to. The physical design of the Koss Porta Pro is quite unusual, unlike most headphones we have seen or see today. Most will identify them as ‘having a unique design’ but, we think the design team at Koss mostly focused on reducing the cost of making the headphone, and those are just our thoughts.
The headphone is mainly made out of plastic. The headband features two simple metal bands that slide against each to provide adjustment mechanism. At both ends, the metal headbands are held in place in a plastic piece that also houses the adjusting mechanisms.
The Porta Pro is a very light headphone. Because of this, the comfort level of the headphone is quite good. They remain very securely in position though their clamping force is very little. Most people have hyped the Porta Pro as being a portable headphone. Though this is the indeed the case, We find these cans better for indoor listening mainly at home or the office. This is principally influenced due to the open-back nature of these headphones.
Now, enough about the looks, let’s get down to how these cans sound.
The lows of this headphone are well executed for an open-back headphone at this price range, though it lacks the tightness you get with expensive headphones. The mids are well balanced while the highs are kind of withdrawn. Though at the price this is quite a good headphone, if your budget allows, moving up to similar models like the Grado SR60i in our list or the Sennheiser PX 10-II, you should get better sound quality.
Early May 2018 the new Porta Pro Wireless headphones were launched. We yet to get a pair, but if you have, kindly share your experience of the new model in the comments.
6. Philips X2/27 Fidelio – Our Open Back Headphone for Gaming
Driver size: 50mm
PROS: Powerful bass
CONS: Requires adjustments everytime they are worn
The Phillips Fidelio X2s have been around for a while now. While the X1 has long been discontinued, they were pretty awesome back in their glory days. But, that is a story for another day. What we have now is the X2, a huge improvement from the X1 with regards to the build and sound quality. At first glance, you would think the X2 and X1 share a lot in common, but, trust me, there are significant changes that have made the X2 make it up to this list.
So why are these cans so good?
Their grandeur starts when you get them out of the box. They are big (full-sized, circumaural) and their quality material and build quality makes them look even more stylish. The headband of the X2 is large, well cushioned by a mesh looking material. The inner headband (hammock style) is suspended and is self-adjusting which eliminates the need for a clicky adjustment system but also requires adjustments every time you need to have them on.
The earpads are large; velour covered and are padded with memory foam for utmost comfort. Unlike the X1, the earpads of the X2 are replaceable which is a useful feature and ensures headphone hygiene is maintained over time. The clamping force of the headphone is fairly tight, but we believe they will self-adjust with time and become more comfortable. The hammock style headband also works to improve the overall comfort level of the headphone. It caused no pressure points while resting on my head (we think this is due to the self-adjusting headband) and can be worn for more extended sessions.
Now let us get to the eagerly awaited topic, the sound quality.
The Sennheiser HD600 is known to be the headphone standards in clarity and neutrality. While this still stands, the Philips Fidelio X2 is arguably just as clear but in a different way. From my direct comparison of the two headphones, the X2 has a massive soundstage with good clarity and instrument separation. The bass response of the X2 is tighter compared to the HD600. On the treble response, the X2 is also better and well balanced while the Mids are about the same on both headphones, but the HD600 definitely tops this.
7. HiFiMAN Sundara – Upper Mid-Fi King
Driver size: Unknown
PROS: Minimalist design, clear, comfortable
CONS: headband could need some improvements
From the likes of the HE1000 that we have had a chance to listen to, down to the much affordable HE400 series, HiFiMAN has been making bigger strides in the headphone industry. For me, HiFiMAN’s design and build quality on their headphones have always been wanting. The HE400-S up on this list was one of HiFiMAN’s cheap planar magnetic headphone that sounded good but was lacking in the build quality. With the HiFiMAN SUNDARA, HiFiMAN has greatly improved on the build quality and the sound is awesome.
The SUNDARA is an over-ear planar magnetic headphone. The headphone has a modest look, matte black color, solidly built with better materials. we like this look, simple and does not show off. The headband arch somehow resembles the Fidelio X2 headband’s design. It is made from steel with a headband strap made of synthetic leather that feels like a high-grade material. The outer linings of the SUNDARA’s earcups are also made of synthetic leather with a breathable mesh fabric against the skin.
Though the earpads are not that thick, but they are quite comfortable. The mesh material on the ear pads as also quite comfortable and does well in keeping the headphone cool when worn. The clamping force of the headphone is quite good, and we do not have an issue with that. Though it lacks padding, the headband straps also work better in distributing and relieving pressure points. The headphone is quite light, weighing in at 379 grams. The LCD2C up on our list measured up to 545 grams.
Overall, the SUNDARA is a good sounding headphone. If you like a slightly cool response sounding headphone, then this might just something you might consider. Like most planar magnetic headphones, the lows are well extended and at a good level. They are not punchy, and through to the mids, they come out softer. The treble is slightly laid back, but unlike the HiFiMAN HE-400S, they are clearer.
8. Shure SRH1440 – Professional Open Back Headphones
Driver size: 40mm
PROS: Comfortable design
CONS: a bit lacking in the bass, a bit heavy
From a mail to order radio parts and kits supplier to a microphone supplier, the Shure brand has seen continued growth here in the US. Shure ventured into the headphones market in the early 2000s, and they have remained focused on providing a better listening experience to its customers.
The Shure SRH1440 are big, full-sized headphones. When we first set my eyes on these cans, we could not help but notice how close their design was to the Sennheiser’s HD range. Though there are visible differences, it seems Shure SRH1440’s design is meant to attract the same audience, though we thought the design was lacking and could use some improvements.
They are constructed from a variety of materials with plastic taking the larger share. The headband is made of plastic and is well padded with synthetic leather. Flexible Metallic strips hold the ear cups frames to the headband and can be adjusted accordingly to fit your head size. The earpads are covered in velour; they are soft, thick and very comfortable. They are also replaceable, and in the box, you will get extra cushions to replace after wearing out the current ones.
Though the headphone looks quite big, like all full-sized headphones, the comfort is great, the clamping force is just as good, and the headphone can fit on many heads without headaches. They are a little on the heavier side and probably should be used moderately or take breaks between long listening sessions.
First time listening to the SRH1440, and we think they might be a little harsh and lacking in the bass. Though for most people the levels are quite good. The mids and treble are well detailed could be because the headphone lacks adequate bass which could distort the mids or treble. Listening to both the SRH1440 and SRH1840’s there are audio differences. While the SRH1840 is quite superior in many aspects, for the price you are getting the SRH1440 makes it a better deal. That said, if we were to choose between the two, we would get the 1840’s due to their sound quality, but they do lack the comfort levels that come with the 1440’s.
9. Beyerdynamic DT 990 PRO – For Gaming and Music
Driver size: Unknown
PROS: Well built, stable, light-weight
CONS: non-removable cable, requires amp
The Beyerdynamic name has been popularly associated with studio cans for decades. The DT100s have been one of the preferred recording headphones since the dawn of time itself by many people and brands. The DT 990 PROs feel more comfortable and albeit cheaper than they look.
The DT990 PRO is a decent looking headphone. We prefer the black color, but you can get a grey pair that looks just as good and for the same price. The DT990 PRO is a headphone built to last, but if you are that person that is prone to accidents, then you need not worry; nearly all the parts on the DT990 PRO are replaceable. The minimalist design and choice of materials the headphone is made from also contribute to make this a very light over-ear headphone.
The headphone is made mainly from plastic. You should not be worried though, because the plastic is of high quality. The headband is made from steel and wrapped with removable slim padding. The earcups are covered with velour which gives this headphone a comfortable feel when having them on.
The headphone is comfortable and lighter despite being a full-size circumaural headphone. The choices of materials make this headphone anything but heavy or bulky. Because of their lightweight nature, comfy earpads and the soft headband, you can have these headphones on for long listening sessions without getting exhausted. However, though the headphone is comfortable and built better, We did not like the cable being hard-wired to the headphone itself. This would make it harder to replace it in case the original cable broke down over time.
Another issue would be the high impedance value. If you are looking to get the best out of this headphone, a headphone amplifier would be a great choice.
We’ve had this headphone for a few months now, and through the time we have learned to appreciate its sound signature.
Starting off with the bass, it is not extremely powerful, but it is just the right amount. The bass is accurate, and you can feel a punch, and it is not muddy. The treble range is where this headphone excels; they are detailed clear and well extended. However, the mids are the weak point of this headphone. The mids came in as a bit recessed, but with an amp boost, you can get the headphone to improve not only the mids but also the bass output.
10. Grado SR60i – Best Sub $100
Driver size: Unknown
PROS: Built to last
CONS: Dated design for new comers
Grado has been in the headphone market for a long time now. Most headphones on their list have been there for a significant portion of the company’s lifetime. With all the tech that has come up in the headphone zone, the brand has stood the test of time. The Grado SR60i is no exception. Formerly known as the Grado SR60, The SR60i is a classic headphone and remains a favorite to most headphone enthusiasts and me.
While there are minor design and driver differences between the original SR60 and the SR60i, the new model still maintains the Grado signature look.
Like most Grado headphones, the SR60i is open back and looks more classy and retro. The Grado SR60i comes with a minimalist design. The headband lacks padding but is quite comfortable, although you would feel uncomfortable after an extended period of having them on. The earpads are well padded and can be replaced over time. The pads are attached to the headband via a thin metal wire that can be adjusted to fit your head size.
When it comes down to sound quality, the SR60i is a highly capable headphone. It is revealing and boasts a balanced tonal range in this price range. The bass, however, lacks authority, but this is a common problem with most open-ears and can be minimized by modifying the earpads. On the other end of the sonic spectrum, the SR60i comes with a decent treble. It is clean, pure and quite extensive at this price. We tried it with different music genres, and we can state it did quite a good job in trying to reproduce the sounds.
Overall, at this price, the sound is nice and clear. The design could do with some improvements and for any audio enthusiast looking to mod headphones; this would be a good start. Like most open cans, they leak a lot of sounds and would preferably be best for home listening.
- Headphone Design: Over-Ear vs. On-Ear vs. In-Ear
- Open Back Vs. Closed Back Headphones
- How Loud are Open-Back Headphones
- Semi Open Back Headphones – Are They Better?
- Impedance Explained
- Sensitivity Explained
- Headphone Drivers Explained: Dynamic vs. Planar Magnetic
There are three headphone fit types. An over-the-ear headphone is usually more comfortable, well padded and I typically prefer these over the other two headphone fits. For home or office listening, they are the best you can get yourself.
Our list of the best open back headphones features mostly over-ear cans. This is because unlike closed back headphones, open backs are preferred for a home or office setting, and in a quiet place so that you can enjoy what these cans have to offer.
On-the-ear cans are somewhat in the middle, They offer some level of comfort but cannot beat their big brothers, the over ears, at this. However, they do come in compact designs and are more portable and less of a show-off than over-ear headphones.
In-the-ear headphones are the ones that either sit inside your ear temples or go inside the ear canals. They are better at sound isolation and are also highly portable. They are relatively cheaper than over-ears or on-ears.
For more information on the three headphone designs head over to our article Headphone Designs Explained: Over-Ear vs On-Ear vs In-Ear
for an elaborate and informative read.
The differences between open-back and closed-back headphones are simple, and all it takes to identify either of the two is the design of the headphone’s enclosure. With a closed-back headphone, the headphone driver is enclosed inside a closed-off earcup. With open-back headphones, the headphone driver is enclosed inside an open earcup that has vents or grills.
Both open and closed-back headphones come with their advantages and disadvantages. Continue reading below to get brief but detailed info of both these designs.
Open Back Headphones
Open-back headphones, because of the open earcup design, are comfortable over long listening sessions, light in weight because of fewer materials, and allows ears to breathe thanks to the ventilation. When it comes to sound, open-backs have a more realistic soundstage construction, natural and have a broad sense of presentation. Because of this, open-back headphones are the best option for critical listening.
The downsides of open-back headphones are; they are not a good portable option, and this is because they leak and also let in too much sound, therefore, might interfere with your music or might be a nuisance to people around you. For bass lovers, open-back headphones lack the punch or thump because of their open design. This makes them a less preferred choice if you are into bass-driven music genres.
Closed Back Headphones
Closed-back headphones because of their design lock in the sound and focuses it on the listener’s ears. The design also keeps out ambient noise; thus, there is no interference in your music. Because closed headphones are good at noise isolation, they are preferred for commuting, use in the office or library, and when you don’t want to be disturbed.
The sound reproduction of closed-back headphones is centrally presented, which is because the drivers are isolated. Isolation of the drivers also makes closed-back headphones reproduce low frequencies (bass) that are tighter and with impact.
The downsides of closed-back headphones are, they cause heat build-up because they lack ventilation and therefore sweating, which can cause fatigue if used for long listening sessions.
If you are trying to decide between open-back and closed-back headphones, read this article (open-back vs. closed-back headphones) before making your final decision. You will know the benefits and drawbacks of each type, and with this information, you will be well informed to make a better decision based on your preferences.
How noisy open-back headphones get will depend on several factors. These are:
- The volume of sound you are listening to
- The model of the open-air headphones you are using
Depending on the volume you are listening to unless you have the headphones cranked up to the max, sound leakage is minimal. On average, noise leakage is comparable to laptop speakers at low volume.
So if it would not be advisable to use open headphones in the library or somewhere, silence is required. Whoever, at home, if you are in a room, you should not be worried about the sound going through the walls.
Semi-Open back headphones lay between open and closed-back headphones. Good examples of semi-open back headphones would be the AKG 240S or the Fostex T50RP. Semi-open headphones will have few holes in the earcup to allow for openness, but most of the earcup is sealed.
While semi-open back headphones will have the benefits of both open and closed headphones, they also bear most of the downsides that come with open headphone designs. If you are in the market looking for the audio quality of open-back headphones and the isolation of closed-back headphones, I think semi-open back headphones are not the way to go. It is better purchasing two headphones, one open and one closed.
Often, the term impedance is used as a specification for headphones.
Impedance describes how much resistant a headphone will give to an audio signal transmitted from an audio source. Most headphones come with impedance values between 20-40 Ohms, which would be a reasonable value for a casual listener.
Headphones with low impedance values will require little power to deliver better audio levels. Because of this, low impedance headphones such as the HiFiMAN HE400S in our list would work with weak amplification gadgets such as mobile phones, portable music players or most portable devices.
On the other hand, higher impedance headphones such as the Sennheiser HD600 will demand more power to give out better audio levels. In this case, they will require amplification to supply power efficiently and boost the audio output.
Read more about headphone impedance and the effect on headphones.
Sensitivity is how efficient any headphone driver uses the power it is supplied with to convert an electrical signal into an audio signal.
The sensitivity of a headphone is measured in decibels (dB) of sound pressure levels (SPL) and indicates how loud a headphone can be when supplied with power at a given range.
High sensitivity in headphones will guarantee the driver performs better without it consuming a lot of power, but there will be chances of distortion when the volume is turned to maximum.
Low sensitivity headphones will require more power but will be more durable than high sensitivity headphones because, despite the high power supplied, the driver unit will not be damaged.
Read more about headphone sensitivity.
While reading through this list, you have seen a few terms continually being used to describe headphone drivers. These are planar magnetic and dynamic drivers.
Planar Magnetic Drivers
Also called orthordynamic or isodynamic headphones, a headphone driver of this type is said to be a crossbreed between electrostatic and dynamic drivers. The Audeze LCD2C and HiFiMAN models in our list use this type of drivers.
Due to the design of the driver, planar magnetic drivers offer very low distortion, unlike dynamic drivers. What this means is that even at high frequencies they do not suffer and can deliver flawless audio reproduction.
Planar magnetic headphones are usually, but not always, more expensive than the dynamic headphones. The HiFiMAN headphones are usually planar magnetic, and most come at friendly budgets including our second pick the He-400S that is priced below $200.
Also called moving coil drivers, this is by far the most common driver type not only on our list but in the headphone market.
The main parts that make up this type are a neodymium magnet, voice coil and a diaphragm which is attached to the voice coil.
Dynamic drivers are said to give out the best bass in the headphone world, and due to their simple working mechanism they are very effective and do not require much power to give out loud volumes.
However, unlike planar magnetic drivers, dynamic drivers are more prone to distortion, especially at high volume.
There are also other headphones drivers such as the balanced armatures which are commonly associated with in-ear headphones. There are also Bone conduction or magnetostriction drivers that sound vibrations to send audio signals to your inner ear via bone conduction and finally electrostatic drivers that are most expensive and hard to use, requiring specialized amps but end up reproducing the best sound.
Read more about the six different types of headphone drivers.