Sennheiser HD 400 Pro review

Sennheiser HD 400 Pro: What is it?

If Special Forces operatives were issued with studio headphones we’d like to imagine they’d look just like these HD 400 Pros. Silky black from the bottom of the cup to top of the headband, there’s zero bling on show here – no chrome surrounds, no shiny plastic panels or brushed stainless steel inserts to catch the eye. 

Even the small Sennheiser script on the headband and tiny logos on the grilles are black on black. So, in the unlikely event, you find yourself in a tactical mix operation, way behind enemy lines, you’ll feel right at home wearing these!

Outwardly, their design is at least a decade old, following exactly the same form factor as the cans in Sennheiser’s HD 500 series. Nevertheless, it’s an iconic look, characterised by beautiful, flowing organic curves and those distinctive arms that dog-leg around the ear cups. Those cups are quite restricted in both tilt and swivel, but not to the degree that it becomes an issue.

The mildly sprung headband conformed to a variety of head sizes, clamping small heads with just enough pressure, but not so tight on larger noggins that they become uncomfortable. Similarly, all manner of ears were comfortably enveloped in Sennheiser’s soft, velour upholstered ear cups. Weighing just 240g, these plush headphones are more than comfortable enough to make short work of long hours at the mixing desk.

• Our pick of the best Sennheiser headphones for recording

Sennheiser HD 400 Pro: Performance and verdict

Closed-back headphones get a bad rap for accentuating bass frequencies, simply because there’s nowhere for the air pressure to escape. True to form, these open-back Sennheiser’s perform superbly in this respect. The liberated airflow also delivers a more spacious, airy and, dare we say, realistic soundstage. Just be aware that isolation is poor, as is to be expected.

Another lovely benefit is that these open cans deliver huge wafts of cooling air to your lugholes, taking comfort levels up another notch. Sweaty, vinyl-cushioned closed-back headphones in the height of summer? No thanks! 

Sennheiser is particularly proud of the 120 Ohm transducer installed in each ear cup. According to its engineers, the “drive magnet offers high power, while its dampening system manages ventilation” resulting in deeper bass while mitigating any distortion that will impact clarity. Those clever engineers have also angled the transducers in order to simulate the position of high-end monitors in a studio. 

Certainly, the frequency response is impressive – from 6Hz to 38kHz – so much so that the bass reaches deeper than the scope of human hearing (roughly 20Hz to 20kHz), and it’s a similar story at the top end. Although we can’t hear some of these highs and lows, it’s quite possible that we can feel them, qualities that help to give us a sense of precision and airiness. 

Take any of these features or characteristics in isolation – the open backs, the angled transducers, the wide frequency response or the neutrality – and it’s unlikely they will make that much of an impression. Bundle them together in a smart, well-built set of cans though, and we believe Sennheiser has succeeded in what it set out to do.

Listening to a variety of music with the HD 400 Pros, everything from Floating Points to Frank Zappa, Masked Wolf to Mozart, there’s an apparent richness, a complexity that lesser headphones just don’t convey. There’s clarity and balance aplenty too, but not the cold, hard treble-toppy steeliness that’s often mistaken for transparency. Instead, there’s a measured vividness; an equality where the mids, lows and highs co-exist without fighting one another. Yep, they sound pretty good!

Some headphones do little for your mix beyond keeping your ears warm, but Sennheiser’s HD 400 Pros will provide you with a level of clarity, spaciousness and honesty that you can properly base creative judgements on. 

Now you can find comfort in the truth, even if the truth doesn’t always make for comfortable listening. 

MusicRadar verdict: These stealthy-looking headphones, with their open-back design and wide frequency response, deliver earfuls of accuracy.

Sennheiser HD 400 Pro: The web says

"These are excellent reference headphones for mixing and mastering and also for tracking with the aforementioned caveat about leakage."
MusicTech

Sennheiser HD 400 Pro: Hands-on demos

Riffs, Beards & Gear

Scan Pro Audio

Produce Like A Pro

Headphone PH

Sennheiser HD 400 Pro: Specifications

• KEY FEATURES High-end, open-back headphones with a transparency ideal for critical listening situations.
• CONTACT: Sennheiser