"What makes planar magnetic headphones different from dynamic headphones?"

"Dynamic headphones use a voice coil attached to a diaphragm, moved by a magnet — like a small speaker. Planar magnetic headphones embed conductors directly in the diaphragm and sandwich it between magnets. The result: the entire diaphragm moves uniformly, which improves transient response (faster, more accurate), reduces distortion, and produces bass with better texture. The trade-off is that planar drivers require more power and are typically heavier."

"Can I use the HE400SE without a dedicated amp?"

"You can make sound from it, but you shouldn't. At 91dB sensitivity, it needs more current than phones and laptops can reliably provide. The result is low volume, compressed dynamics, and a flat, lifeless bass response. Even the $99 FiiO K5 Pro ESS transforms the experience. Budget for both headphone and amp when planning your purchase."

"HE400SE vs HiFiMAN Sundara — is the upgrade worth it?"

"The Sundara ($349) sounds noticeably more refined — better extension at both frequency extremes, tighter imaging, and a more polished overall presentation. But the gap is not dramatic enough to justify the price difference for most listeners new to planar magnetics. Start with the HE400SE, learn what you love about planar sound, then upgrade to the Sundara when you're ready."

HiFiMAN HE400SE Review (2026)

The HiFiMAN HE400SE brings planar magnetic technology to $149. We test whether it actually sounds better than dynamic headphones at the same price.

What Even Is a Planar Magnetic Headphone?

Before getting into the HiFiMAN HE400SE itself, it’s worth explaining why anyone would pay $149 for a headphone that requires a dedicated amplifier when you could spend the same money on something that works fine from your phone.

Planar magnetic headphones work differently from the dynamic drivers in most headphones and speakers. Instead of a coil attached to a cone that’s pushed in and out by a magnet, planar magnetic drivers embed a network of conductors directly into a large, flat diaphragm that sits between two arrays of permanent magnets. When current flows through those conductors, the entire diaphragm moves — uniformly, precisely, with every point of the membrane responding to the signal simultaneously.

The result, done well, is driver behaviour that dynamic headphones genuinely struggle to replicate: faster transient response (the diaphragm starts and stops more accurately), lower distortion at medium and high volumes, and bass that has texture and definition rather than just impact. The HE400SE is HiFiMAN’s attempt to make this technology accessible at $149. Whether it succeeds is what this review is about.

Design and Build Quality: The Honest Assessment

This is where the HE400SE asks you to make a trade-off, and it’s worth being clear about it. The build quality is not impressive for $149. The plastic used in the earcup assemblies has a hollow, slightly toy-like quality compared to Beyerdynamic’s studio headphones or even the Audio-Technica ATH-M50x. The headband has a reputation in the community for being uncomfortable over extended sessions without an aftermarket headband modification.

The ear pads are adequate — soft enough, with an ear opening large enough for most ears. The stock cable is mediocre: thin and prone to tangling. Most HE400SE owners replace it within a few months.

What the HE400SE does have is a large, airy ear cup design that doesn’t cause heat buildup, and a lightweight clamping force that’s comfortable for medium-length sessions despite the relatively heavy overall weight.

Here’s the realistic framing: if build quality is your primary concern, the Beyerdynamic DT 990 Pro or DT 770 Pro at the same price will feel significantly more premium in hand. But people don’t buy planar magnetic headphones for the plastic quality — they buy them for what the drivers do.

Sound Quality: Where the HE400SE Justifies Its Existence

Within about 30 seconds of hearing the HE400SE properly driven, the reasons for the planar hype become clear. The first thing you notice is the bass — not because it’s elevated, but because it has a texture and definition that sounds different from dynamic bass. Bass guitar sounds like bass guitar: individual strings have weight and body, not just thump. Kick drums have attack and decay that makes them feel like physical events rather than abstract thumps.

The tonal balance is roughly neutral with a slight mid-bass lift and a smooth, slightly relaxed treble. It’s not as bright as the DT 990 Pro or as warm as the HD 650 — it sits in between, natural and honest. Vocals are present and clear. Acoustic instruments have good timbre. Electronic music benefits enormously from the bass definition.

Imaging is one of the HE400SE’s strongest attributes. Instruments in stereo recordings sit in clearly defined positions. Binaural audio is impressive. The soundstage is wide for a closed-ear experience — wider than any closed-back at this price, approaching some open-back designs.

The Amplifier Requirement: Critical, Not Optional

The 91dB sensitivity figure is what most reviews should emphasise more than they do. From a phone at full volume, the HE400SE is barely loud enough for comfortable listening, and the bass response is noticeably thin and compressed. From a dedicated desktop amp with proper current delivery, everything changes.

The FiiO K5 Pro ESS at $99 is the community’s go-to budget pairing. The Topping DX3 Pro+ at $139 works well. The Schiit Asgard 3 at $199 is where the HE400SE really opens up, with bass that’s genuinely impressive and a midrange that becomes almost addictively natural.

Budget for the amp. The HE400SE sounds like a disappointment without one and a revelation with one.

Compared to Dynamic Alternatives

The Audio-Technica ATH-M50x and Beyerdynamic DT 770 Pro are the obvious closed-back comparisons at $149. Both sound good. Neither sounds like the HE400SE.

The planar advantage is most audible in fast, complex music: the HE400SE tracks rapid guitar arpeggios, complex drum patterns, and layered synth pads with a cleanliness that the dynamic alternatives blur slightly. It’s not that the M50x or DT 770 are bad headphones — they’re both excellent. It’s that the HE400SE does something genuinely different that, once heard, is hard to unfavour.

Final Verdict

The HiFiMAN HE400SE is the best reason to own a desktop amplifier that exists under $200. The build quality is not impressive, the stock cable is replaceable immediately, and the amp requirement is real. None of that changes what the drivers produce when given proper current: one of the most technically capable and natural-sounding presentations available at its price point, with bass texture and imaging that stand out from anything using a dynamic driver.

HiFiMAN HE400SE Review (2026): Budget Planar King?