Sennheiser HD 620S – Pros and Cons Review

A Closed-Back Gem with Open-Back Aspirations

Sennheiser’s HD 600 series has long been a cornerstone for audiophiles, celebrated for its open-back designs that deliver expansive soundstages and pristine audio clarity. The Sennheiser HD 620S, introduces a closed-back variant to this iconic lineup, aiming to blend the airy sound of open-back headphones with the isolation benefits of a closed design. After spending time with these headphones, here’s a detailed look at their performance, design, and where they shine or fall short.

Design and Comfort

The HD 620S sports a sleek, understated aesthetic, drawing visual cues from the HD 500 series, particularly the HD 560S, with a speckled earcup finish and a robust, steel-reinforced headband. The build is primarily plastic but feels sturdy, with no creaks or flimsiness, though some flex noise in the housing is noticeable when adjusting.

Weighing 326g without the cable, they’re heavier than their open-back siblings but remain comfortable for extended sessions due to thick, synthetic leather earpads and substantial headband padding. The earcups are spacious, accommodating most ear sizes, and the 5mm-deep pads enhance comfort by avoiding pressure on the ears. However, the clamping force is initially tight, which may cause discomfort for some, especially glasses-wearers, though it loosens over time.

The included 1.8m detachable cable with a 3.5mm jack (and 6.3mm adapter) is functional but lacks an inline mic option at launch, with Sennheiser promising a 4.4mm balanced cable later. A flimsy cloth carry pouch is a minor letdown for portability.

Sound Quality

The HD 620S aims to deliver an open-back-like soundstage in a closed-back design, and it largely succeeds. Powered by custom-tuned 42mm dynamic drivers with a 150Ω impedance, these headphones are easier to drive than the 300Ω HD 600 series models, making them versatile for use with portable devices or modest DACs like the iFi Zen DAC V2.

The sound signature is neutral, with a spacious, detailed presentation that excels across genres, particularly jazz, classical, and country. The mids are a highlight, offering clear, natural vocals and excellent instrument separation, as heard in tracks like Joni Mitchell’s “Carey.” The bass is well-extended and detailed, though it lacks the punchy impact some might crave, leaning toward a smooth, controlled response. The treble, however, is inconsistent—sometimes peaky or dull, as noted with tracks like George Michael’s “Soul Free,” which can feel flat. The soundstage is impressively wide for a closed-back, though not as open as the HD 660S2, and imaging is precise, making these headphones suitable for gaming and professional use. Passive isolation is effective, blocking about 65% of high-frequency noise, ideal for home or office environments, but low-end noise like engines can still intrude.

PROS

Spacious Soundstage: Remarkably open for a closed-back, rivaling some open-back models.

Comfortable Design: Deep earpads and padded headband ensure long-term wearability.

Versatile Drivability: 150Ω impedance works with a range of devices, from dongles to desktop amps.

Excellent Mids: Clear, natural vocals and instrument separation shine.
Solid Isolation: Effective for home or office use, with no sound leakage.

CONS

Treble Inconsistency: Can be peaky or dull, impacting some tracks’ energy.

Clamping Force: Initially tight, potentially uncomfortable for some users.

Flimsy Carry Pouch: Offers minimal protection for portability.

Cable Limitations: No inline mic or balanced cable included at launch.

VERDICT

The Sennheiser HD 620S is a compelling addition to the HD 600 series, offering a rare blend of closed-back isolation and open-back-like spaciousness. Its neutral sound, comfortable design, and versatility make it ideal for audiophiles seeking high-fidelity audio at home or in quieter public settings. While the treble inconsistencies and initial clamp force are drawbacks, they don’t overshadow the headphones’ strengths. The HD 620S is a strong contender in the mid-fi closed-back market, especially for those prioritizing soundstage and clarity over bass-heavy punch. Pair it with a quality DAC for the best experience, and you’ll have a headphone that delivers both at home and on the go. Hurry up and buy yours now for the best price 👇