Sennheiser HD 620S Review

The Sennheiser HD 620S occupies a genuinely interesting spot in the headphone world. It's a closed-back that dares to live in the same family as the legendary HD 6XX — and remarkably, it mostly earns that comparison. Not by being a carbon copy, but by carrying over what makes those open-backs special while bringing something distinct to the table.

The Closed-Back 6XX — But Make It Better in Some Ways

One Reddit user who owns around 15 pairs of headphones — including the HD 6XX, Focal Hadenys, and Elegia — put it plainly after picking up the 620S on sale: the description of "closed-back 6XX" is accurate. The mids have that same Sennheiser house character, the build feels solid and robust like a 6 series rather than the cheaper plasticky feel of the 5 series, and the detail retrieval is genuinely impressive for a closed-back at this price point.

But here's where it gets interesting — the 620S doesn't just approximate the 6XX experience. In a few areas, it's actually ahead. There's more treble extension (without tipping into sharpness), a touch more bass, and — perhaps most surprisingly for a closed-back — a better soundstage with more precise instrument placement than the 6XX. That last point will raise eyebrows among open-back purists, but multiple listeners corroborate it.

The "Boxy" Closed-Back Problem — Is It a Problem Here?

Every closed-back fights the same battle: that slightly enclosed, boxy quality where sound feels like it's bouncing around the cups rather than breathing freely. The HD 620S doesn't fully escape this — it's a physics problem, not a design failure — but it handles it better than most. Compared to the Audio Technica M50, the A900X, or the Focal Elegia, the 620S sounds noticeably more open and natural. It won't fool you into thinking you're wearing an open-back, but it's about as good as a closed-back gets without resorting to acoustic tricks that compromise isolation.

Build and Comfort: Mostly Good News

The clamp force has been a talking point online — some early forum posts flagged it as excessive. Real-world experience tells a more nuanced story: most users find it firm but not painful, and it settles with use. Noise isolation is strong for a passive headphone, which is exactly what you want from a closed-back workhorse.

The faux leather pads are a practical win. They're easy to wipe down, which matters more than you'd think over months of use. Compare that to something like the Elegia, where sweat and oils slowly destroy the pad material — the 620S is the more durable long-term choice. The flip side: they do trap heat, so extended sessions in warm environments can get uncomfortable.

The detachable cable is a real quality-of-life feature that doesn't get enough credit. Cables fail. Connectors wear out. On a headphone built to last years, being able to swap a cable is genuinely important.

Who This Is Actually For

The 620S makes most sense as a wired workhorse. One buyer framed it perfectly: they already had AirPods and AirPods Max for wireless convenience, but wanted something durable and reliable with no battery to degrade and no electronics to become obsolete. That framing cuts through a lot of the audiophile noise — this is the headphone you reach for when you want to just plug in and listen without worrying about firmware updates or battery percentages.

At full retail ($400 USD), it's a reasonable but not obvious choice. At the sale prices it's been hitting — $229 on Amazon, around $299 CAD in Canada — it becomes something close to a no-brainer for anyone in the closed-back market at that tier. The community has been vocal: when it drops, it's genuinely one of the better deals in the sub-$300 closed-back space.

The Competition Context

Worth noting: Sennheiser has since released the HDB 630, a wireless version that sits conceptually adjacent to the 620S in the 600 series lineup. If wireless is important to you at all, that's worth investigating — frequency response comparisons between the two show the HDB 630 tuned as a kind of spiritual sibling. But if you specifically want wired-only, the 620S remains the cleaner, simpler choice with no battery anxiety and no DSP dependency.

One Reddit user did replace their 620S with a Meze Strada, citing build and comfort concerns — so it's worth noting this isn't universally loved. For some users, the clamp and the heat accumulation are deal-breakers. If you can try before buying, do it.

Frequently Asked Questions

Q: Is the Sennheiser HD 620S worth buying at full price?

A: At $400, it's competitive but not an obvious slam dunk. At the sale prices it frequently hits ($229–$299), it becomes one of the stronger value propositions in the closed-back market. Watch for discounts — they happen regularly.

Q: How does the HD 620S compare to the HD 6XX / HD 650?

A: The 620S trades some of the 6XX's midrange magic for more treble extension, a bit more bass, and — notably — better soundstage and instrument separation for a closed-back. It's a different flavor, not a strict upgrade or downgrade.

Q: Does the HD 620S require an amplifier?

A: Sources don't specify an exact impedance rating, but as a 600-series Sennheiser, it will benefit from a decent source. A dedicated DAC/amp or a capable dongle will get you noticeably better performance than a phone jack alone.

Q: How does the passive noise isolation hold up?

A: Reviewers describe it as very good for a passive (non-ANC) headphone. It won't match active noise cancellation in loud environments, but it's strong enough for office use and commuting.

Q: Is the HD 620S or the new HDB 630 a better buy?

A: Completely different products for different needs. The 620S is wired-only, simpler, and will never have battery or electronics obsolescence issues. The HDB 630 adds Bluetooth, ANC, and app-based EQ at $500, but requires charging and has DSP always running. Choose based on whether wireless matters to you.

The HD 620S is the rare closed-back that doesn't feel like a compromise. It borrows the best traits of the HD 600 family — those mids, that build quality, that longevity — and wraps them in an isolating design that's more practical for real-world listening environments. It won't replace an open-back in a quiet room for critical listening, and the heat buildup during long sessions is real. But as a durable, no-fuss wired closed-back that you can hand down to your kids someday? Few things at this price come close.

— Tech Lead Editor, CPrice