Review: Sennheiser HD 620S, bridging the gap from consumer to audiophile

Sennheiser is a brand that straddles the consumer and audiophile fence with a foot on either side.  While they have some sets of headphones that are true audiophile quality, they also make a relatively more affordable hi-fidelity headphone for the less discerning consumer.

Sennheiser sent us a set of their latest over-ear headphones to test out, the HD 620S, which are priced at RRP $599.95.  Now while they are not all that affordable, they are a lot more affordable than their upper end audiophile-quality headphones.

The Sennheiser HD 620S are not wireless, instead are wired with a 1.8m cable which terminates to a single-ended 3.5mm stereo plug with an integrated locking screw for the included 6.3mm adapter.

Design and comfort

While the HD 620S belong to the open-backed 600 series of Sennheiser headphones, they are closed back but promise to deliver open-backed quality sound alongside the advantages of a closed-back headphone.

The headband includes reinforced metal but also has a substantial amount of padding on it making it incredibly comfortable for long periods of wear.  The headband may have the metal inside but the rest of the frame feels a bit plasticky – but the plastic is still strong and incredibly lightweight.

Rather than waste weight on a metal frame Sennheiser has opted for the plastic and although it feels and looks plain, I’m all here for it.  Wearing these for a long time was a breeze without any excessive pressure on the top of my head at any time.

The external earcups have a textured finish that is speckled which is nice and breaks up the plasticky smooth feel of the frame.  Inside, the earcups have a fair amount of soft cushioning covered with soft leather which do not create too much heat in a long session.  It isn’t really warm these days in Melbourne though so that test is subjective – although my wife does have the heater on 22 degrees every night!

The earcups provide enough pressure on the sides of the head to take some of the pressure off the headband without being overly tight.  If anything, the pressure is a bit too high but wearing my glasses on long listening periods were not all uncomfortable.  The pressure creates that tight seal you need with these closed-back headphones (which do not have ANC).  I was able to wear the headphones and all external noise was blocked out, including the Roborock robot vacuum around my feet and the dogs barking at it!

The headband is adjustable and the earcups have a small amount of swivel to them to help them fit your head comfortably.

Inside each earcup is a custom-tuned 42mm dynamic transducer with a 150-ohm aluminium voice coil which “excels at speedy transients and well-defined instrument tails for punchy dynamics across the entire frequency spectrum.”  All sounds well and good for sure and excel is a relative term in this case.  More on the sound quality below.

Sennheiser includes a soft case to keep the headphones dust free and to prevent damage during travelling.  

The HD 620S from Sennheiser is a wired headphone as stated above.  The cable though is actually removable/replaceable so you can use your own cable, even one with an inline remote if you wish.

Sound quality

Sennheiser has positioned the HD 620S wired headphones somewhere between audiophile and consumer pricing, although upper end consumer headphones are extending to this $600 regularly these days.

The HD 620S are designed for both audiophiles and passionate gamers who want great quality sound across the entire spectrum so that even the smallest of cymbals or footsteps will make an impression on you.

At the low end, the bass, the sound is fairly extensive with a deep punchy bass sounding great across bass-heavy songs.  It lacks a bit of crisp punch that you’ll get from true audiophile headphones, but it is still great – especially for $600.

The mids are excellent with a very natural sound that we have come to expect from Sennheiser.  The range is extensive while also being precise in its sound reproduction.

The highs are a bit lacking to be honest – and let’s face it our reviews here at EFTM are honest (something some companies dislike but we tell it like it is).  The upper register just doesn’t seem to have the crispness you would hope for with a set of headphones from Sennheiser.  They still sound good but I just wanted more punch in that upper range – this could be fixed by using a desktop amp and an equaliser but I don’t have that on hand at the moment.

Sennheiser has tried to create an open-back sound in a closed headphone and although it isn’t quite up to that of an open-backed headphone it is still very airy.

Comparison

I don’t have many high end wired headphones lying around but I hooked up my Focal Bathys headphones using the included cable.

Now the Focal Bathys originally sold for $1500 so it isn’t really fair and after using both I can see why.  The Bathys offer that clearer, upper end punch that I was looking for on the HD 620S.  The HD 620S though was able to compete somewhat with the Bathys on other levels though but there is a clear difference (plus about $900 on RRP!) in sound quality between the two.

Compared to Bose QC40 in a wired configuration the Sennheiser HD 620S were much more comparable.  The bass was crisper, the mids were clearer by a long way but the Sennheiser lagged behind once again in the upper register – not by much this time.  Overall the sound was better on the Sennheisers thanks to this accurate and decisive mid-range but you may want to play with your equaliser/amp to help it in the upper end to get a better sound.

Who buys these?

The Sennheiser HD 620S headphones fit comfortably on the head with a small amount of swivel on the earcups and an extremely well padded headband which adjusts easily. They clamp on the ears well, without being overly tight that it becomes uncomfortable for extended listening periods.

They sound great and although are a step down from true audiophile headphones, they sound better than any other ‘consumer’ headphones I’ve used in recent times. They are priced at the upper end of consumer headphone pricing, albeit $100 more than the current price of the best Bose consumer headphones on the market (some places have the Bose at over $550 so shop around) but are a long way from the thousands of dollars you will par for a decent audiophile set of headphones.

Their sound is not up to the quality of the audiophile headphones in a wired connection (and nowhere near the price either!), and the audiophile headphones I compared them to were at the lower end of that market segment. The main issue with the Sennheiser HD 620S headphones is that they are wired only with no wireless options available on them at all.

Buy these if you want something that produces sound quality at the top end of the consumer headphone market without having to pay too much more than others. Do not buy these if you want true audiophile quality sound — the sound is good but not that good.

The Sennheiser HD 620S are available now from sennheiser-hearing.com with an MSRP of $599.95 AUD / $639.95 NZD.