General Information

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The HD 620S headphones are a purist's delight with the ideal configuration for immersive listening sessions in seclusion. They uphold the revered sonic traits of their 600-series lineage: exceptional texture reproduction, intimate vocals, and distortion-free sound across all volumes, yet with a surprisingly "open" soundstage. If you seek a captivating, high-performance set of sealed cans, these deserve a closer look.

At the core of the HD 620S is the renowned 600 series technology, boasting a custom-tuned 42mm dynamic transducer crafted at Sennheiser's Tullamore factory. Its evolved design challenges traditional closed-back assumptions, delivering superb detail retrieval and a modernized tuning that enhances nuance and clarity.

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Sennheiser's iconic chassis ensures extended listening comfort while the angled transducer geometry creates expansive panoramic imaging, immersing the listener in a front-row experience. Constructed with carefully selected acoustics-first materials, the HD 620S minimizes unnecessary reflections and reproduce deep, punchy bass. Built to endure, they feature a metal-reinforced headband, luxurious earpads, and a versatile cable system that lets you swap cables in seconds--a must for audiophiles looking to connect to balanced audio chains, gaming setups, portable DAPs and more.


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Features:
  • 38mm (diaphragm; 42mm overall) dynamic transducers
  • Coupling: Over-ear (circumaural), synthetic leather pads
  • Acoustic principle: Closed-back (sealed)
  • Transducer: Dynamic, 42mm (38mm diaphragm)
  • Frequency response: 6 - 30,000 Hz
  • Impedance: 150 Ω impedance and ultra-light aluminum voice coil for outstanding detail retrieval
  • SPL: 110 dB (1 kHz / 1 Vrms)
  • Total Harmonic Distortion: <0.05% @ 1 kHz, 90 dB
  • Headband: metal reinforced, adjustable slider
  • Weight: 326g (without cable)
  • Cable: 1.8m (~6ft) with 3.5mm (⅛-inch) stereo plug; includes 3.5mm to 6.3mm (¼-inch) adapter; single-sided entry
  • Cinched storage pouch for low-profile storage and protection from dust
  • Wired for balanced operation; balanced cable sold separately (part number 700403)
  • Also compatible with in-line mic cable (cable sold separately, part number 572281)
Click for product page
Spare parts page (coming soon)
Official announcement

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Latest reviews

gc335

Headphoneus Supremus
Great budget closed-back headphone
Pros: Great sound
Comfortable
Planar like speed
Quality build
Light
Great imaging
Soundstage
Cons: Clampy out of the box
Might be a bit bass light for some genres/preferences (seems to improve with time)
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Intro and disclaimer

I was very excited to hear about a new budget friendly closed-back Sennheiser headphone. I have been looking for a mobile closed-back option for listening on the couch with a DAP. I picked up the DCA Audio E3 after hearing it at CanJam NYC this past February. The E3 sounds stunning and is my personal closed-back benchmark. The issue is that it needs a solid desktop source to sound up to its potential. Does the HD620S fit the gap in my collection? Let’s find out.

I wanted to get this review out as soon as the embargo was lifted but after a ton of time with the 620S, my opinions changed a bit and I felt the need to go back and make some changes. I don’t know if these burned in, or my brain adjusted. I like these a lot right out of the box but felt they were a bit bass light. After about 50 hours of listening, I’m starting to feel a bit different. I enjoy them a lot. Their sound has really grown on me.

The HD620S was provided to me by Sennheiser in exchange for my honest impressions. At no time did they influence my review. My thoughts are my own.

Gear Used

Sennheiser HD620S
Beyerdynamic DT770 Pro 250 Ohm
Sennheiser HD6XX
Schiit Modius E
Schiit Jotunheim 2
Fiio M15S
iBasso DX300 Max
Hiby M300

Packaging/Unboxing

The packaging is very basic. It’s just a box with the standard Sennheiser colors with the headphones held in place and protected by a cardboard cutout. I like it. The money you spend is going to what you really want…. A headphone.

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Accessories

The HD620S comes with a black travel pouch, and a cable that terminates into 3.5 with a ¼” screw on adapter. The cable is basic ad gets the job done. It’s about 6’ long and does a pretty good job of not tangling. For most of my review, I used the Hart Audio compatible (HC-6-b) with the HD500 series of headphones. This allowed me to use the HD620S with my balanced gear. I was happy to see that the jack for the HD620S uses a 4-pole 2.5 balanced connector. A balanced cable will be available directly from Sennheiser sometime in the near future.

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Build

The build is like most of the HD500 line. Lots of plastic. That said, it’s light, high quality and completely squeak free. There is metal in the headband. The cups have a nice texture that does add a bit to a more premium feel. I have no complaints about construction or concern for long-term durability.

The pads and headband are glued on and made of synthetic leather. They have a nice soft and premium feel to them. It almost feels like lamb skin. No complaints about the headband or pads. The nice thing about Sennheiser is that if you do need parts down the road, they're easy to get.

The headband adjusts easily and has a nice solid click as you adjust the head band.

Comfort

The HD6020S is a bit clampy out of the box but with a bit of use and a slight stretch of the headband, became very comfortable. I have zero issues wearing these for hours. They are also extremely light which really helps with the comfort.


Overall sound signature

I’m going to start off by saying these headphones are (at least to my ears) super sensitive to position over the ear. Slight repositioning over the ear yielded significant changes to the sound. Be sure to move them around a bit to find the sweet spot.

These are very neutral with nice detail. I don’t notice an emphasis on any part of the signature. At no time did I experience any type of bass bloat or harness in the sound. The HD620S seems to bring out details that I haven’t noticed before in tracks that I’ve heard dozens of times.

I referred to my notes on early impressions and wrote down that:

- Imaging! Wow
- Detailed! It brings out nuances in some tracks that I have not noticed before.
- Are these planar?! Guitar sting plucks have that planar like attack. I tend to like planars better than dynamic driver headphones. I truly forget sometime that I’m listening to a dynamic driver headphone when I’m listening to the HD620S.

Sound Anayis

I’ll briefly go into my thoughts about bass, mids, and treble. I find it a bit easier to describe a headphone’s characteristics when I compare them to other headphones.

Bass
If you are looking for thumping bass, you may want to look elsewhere. The bass on the HD620s is nice and tight, well controlled, and doesn’t bleed into the mids but they just don’t have the impact that some might want for pop and EDM. For classical, folk and classic rock I didn’t feel like I was missing anything.

Mids
Again, very neutral. I didn’t notice any dips with male vocals, female vocals, or mid centric instruments.

Treble
I like treble! The HD620S didn’t disappoint. At no point was there any harshness in the tracks that I tried. High hats have a nice metallic shimmer. Lies from Eric Clapton and friends got really close to being uncomfortable but never got too aggressive.

Stage/Imaging
These are closed?! The staging is not HD800S levels but for a closed-back can, I was very impressed. Live tracks sounded very open. Imaging is extremely good. I use Yosi Horikawa’s Bubbles to test imaging and the HD620S didn’t disappoint. Each sound's location was very clearly defined.


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Comparisons

For this comparison, I used the Mojo 2 with no EQ. The dual 3.5mm outputs make it easy to A/B.

Afterglow - Emancipator
HD620S - The track is my go-to for sub-bass. It reaches nice and low but is just does not have the impact that I get with some other headphones.
HD6XX - Less bass impact versus the HD620S which is to be expected. There is also a bit less bite to the treble. Here is feel like I’m listening to a dynamic driver versus the planar like HD620S driver. The HD620S has more detail and clarity
DT770 (250 ohm) - The HD620S sounds a lot better with this track. The Beyer has even less bass. It sounds very thin and even harsh in the treble and upper mids in comparison to the HD620S. The staging here is weird. It almost moves behind me when compared to the HD620S. Imaging is better in the HD620S. Staging feels too wide for this track.

Lindsey Stirling - Elements (Orchestral Version)
HD620S - Ok, here we go. This track sounds great on the HD620. Bass impact isn’t huge, but I don’t feel like I’m missing something. The sound is nice and open. The chimes have a nice sparkle to them and move nicely left to right. The violin sounds natural. The HD620 shines with this track. Zero harness and no dips anywhere.
HD6XX - The staging is narrower but a bit taller. Again, less bass. A bit smoother. There is less sparkly to the chimes but the violin sounds amazing. Really natural and nicely centered and forward in the presentation.
DT770 (250 ohm) - Again the staging is weird here. It feels too wide compared to the HD620. The sound is a bit muffled in comparison to the HD620S. The chimes sound distant and don’t have the same metallic sound that the HD620 has. The violin sounds father away and not as much the focus of the track like it should be. It’s not bad after letting my brain adjust for a bit but I still prefer the HD620S this track.

Grateful Dead - Touch of Gray
HD620S - Decent kick drum impact. Nice detail without harshness. Classic rock sounds very nice on these.
HD6XX - Again, the staging is more compressed than the HD620S. Not as much energy in the treble and a bit less impact in the bass. That said, the HD6XX shines with classic rock in my opinion.
DT770 (250 ohm) - Same thing. The stage seems cut in half in the middle. Vocals seem like they’re coming from the left and right and do not have that center stage feeling. This perception does diminish a bit with more time. I think your brain adjusts to it.

Angus and Julia Stone - Yellow Brick Road
HD620S - The bass on this track can be a bit boomy but not with the HD620S. Again, I really feel like I’m listening to a planar. The guitar sounds so good. Nice detail. I ended up just finishing the track instead of jumping around.
HD6XX - Staging is more intimate. The vocals are more in your head. Not a bad thing. Staging is yet again a bit narrower but taller. Smoother all around. Less detail but smoother. These sound very good as well. No boomy bass. Natural and organic. These are a crazy good value.
DT770 (250 ohm) - Less bass and wider stage. I do like this track with the DT770. Imaging is a bit mushy compared to the HD620S. I don’t want to come across as knocking the 770. I really enjoy these headphones especially when modded but when you A/B them right after one another, you can’t help but feel that the HD620S is better sounding headphone. It may come down to preference.

Alison Krause - It Doesn’t Matter
HD620S - These headphones were made for this track. Wow! There is a nice rumble with this track. The vocals are nicely forward and natural. The staging is just right. It had a nice live concert feel to it.
HD6XX - Right away, the 6XX feels softer. The staging is a bit more intimate. Significantly less rumble in the bass and less detail. None of these differences are necessarily a bad thing. This track is still enjoyable with these headphones. It’s just a different flavor.
DT770 (250 ohm) - Yet again, the vocals feel like they are split down the middle. It doesn’t feel centered. Decedent rumble in the bass. Slight hint of sibilance in the vocals. I’d reach for the HD620S or HD6XX before the 770 for this track. Again, not bad but I think something like classical would play better with the 770.

Eric Clapton - Old Love Unplugged
HD620S - I’m loving this track with the HD620S. The staging of Sennheiser accentuates the feeling of being live. There can be some harshness in the piano 6:16 but not with the HD620S. I’m not missing any punch or warmth. The tuning is spot on for this track.
HD6XX - Again, a bit softer sounding. Narrower stage and a less energy in the treble. Very smooth. These are so easy to listen to found hours on end.
DT770 (250 ohm) - I spend a bit more time letting my ears adjust to this track. Besides the vocals being disjointed, it was very enjoyable. Nice tight bass and no harshness. Super wide staging

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Sources

For most of the review, I used the Chord Mojo 2. It’s a very good little DAC/amp and has the benefit of two 3.5 outputs. It makes it easier to A/B during reviews. I did want to add a few comparisons between different sources to see how the HD620 scales.

Schiit Jotunheim 2/Schiit Modius ESS - Right away, I notice a bit more rumble in the subbass. Staging feels a bit more around you versus in front of you with Mojo. The sound is a touch more aggressive with the Jot and you feel like you’re getting a bit more detail. There’s a noticeable step up in sound with this stack over the Mojo 2. The HS620S is scaled very well and pairs extremely well with this setup.

Schiit Vali 3 (stock tube)/ Schiit Modius ESS - Staging is a bit less 3D but still good. The sound is touch softer and a bit more mid bass versus sub. Again, another great pairing. The Vali 3 with a Modi paired with the HD620S is one of the best sub $700 rigs you can get in my opinion.

iBasso DX300 Max - This sounds very close to the Jot stack. Lots of detail. Nice rumble in the bass.

Fiio M15S - Slightly less detail versus the Max and the staging isn’t quite as good. There is also slightly less bass impact. Still a good pairing.

Hiby M300 - I must admit that I’m surprised how well the Hiby does. Nice detail but a little smoother than the Fiio, iBasso and Jot. Staging is a bit flatter but not by much. Very impressed with the Hiby. Although the HD620S scales well, you don’t need a crazy expensive source to enjoy it.

Conclusion

Congratulations Sennheiser on an extremely good headphone. I know that these will be in heavy rotation within my collection. I would probably reach for a different closed-back or IEM for EDM but for everything else, they will see a lot of use. I like the HD620S a lot right out of the box, but they did grow on me even more after more time with them. If it's not your cup of tea out of the box, give it some time. I'm not a huge believer in burn-in but with this headphone, it seems to be important.

These will definitely work for my couch listening and on the go use when I don't feel like using IEMs.
Last edited:
ericpalonen
ericpalonen
Thank you for these awesome comparisons. Some of these test tracks are terrific and I think we will add some to the @Sennheiser CanJam playlists. I need to try that Vali 3 rig...did the clean signature lean a little warmer with it?
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gc335
gc335
Yes, the Vali is a great pairing. Definitely adds a little tube flavor but not sacrificing too much clarity.

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