Updated October 2026 · prices checked Oct 10, 2026.
The Upgrade Question
The HE400SE is HiFiMAN’s entry planar; the Sundara is the step up most owners make next. Prices for both move a lot with HiFiMAN’s frequent sales, so check the current price rather than trusting an old figure. The real question is whether the Sundara’s refinement is worth the gap at the moment you buy.
The cheapest way into planar bass and low distortion. Put the savings toward a small DAC/amp.
Smoother treble, fuller mids and more precise imaging, per long-running owner consensus. The one people keep for years.
Short answer: for most listeners the Sundara is worth it, and it is not harder to drive than the HE400SE. The “Sundara needs a huge amp” idea is mostly forum folklore; the specs below show why.
Specs Comparison
| HiFiMAN HE400SE | HiFiMAN Sundara | |
|---|---|---|
| Driver type | Planar magnetic | Planar magnetic |
| Design | Open-back | Open-back |
| Impedance | 25Ω | 37Ω |
| Sensitivity | 91 dB/mW | 94 dB/mW |
| Weight | 390 g | 372 g |
| Cable | 3.5 mm + 6.35 mm adapter | 3.5 mm + 6.35 mm adapter |
| Price (Oct 2026) | Check current price | Check current price |
Sound Character
These descriptions summarise published measurements and the consistent owner consensus on Head-Fi and r/headphones. They are not personal listening notes.
HE400SE: The Budget Planar
The HE400SE delivers the core planar strengths (low distortion, fast transients, tight extended bass) at the bottom of the planar price range.
Bass is its calling card: extended and controlled. Owners commonly describe the midrange as slightly lean, with a mild dip in the upper-bass and lower-midrange region. The treble has a peak in the 6–8 kHz area, which reads as detail on most recordings and as brightness on some.
Staging is wide for the price, though owners describe it as less deep and less precise than the Sundara’s.
Sundara: The Refined Planar
HiFiMAN has revised the Sundara several times; the current version ships with improved pads and cable. The differences owners most often report over the HE400SE:
- Treble: more extended and more even, with less peakiness.
- Midrange: fuller, with more natural timbre on voices and instruments.
- Imaging: more precise placement of instruments.
- Soundstage: similar width, more depth.
- Bass: similar quantity, with tighter control.
Amp Requirements: The Math
Converting the published sensitivity to the voltage, current and power needed for 110 dB peaks (S_dBV = dB/mW + 10·log10(1000/Z)):
| HE400SE (25Ω, 91 dB/mW) | Sundara (37Ω, 94 dB/mW) | |
|---|---|---|
| Sensitivity in dB/V | ~107 dB/V | ~108 dB/V |
| Voltage for 110 dB peaks | ~1.4 V | ~1.2 V |
| Current | ~56 mA | ~33 mA |
| Power | ~80 mW | ~40 mW |
So the HE400SE needs about twice the power of the Sundara for the same loudness. Neither is hard to drive by desktop standards, but both outrun a phone jack (around 1 V, with limited current). What planars do want is current capability and a low output impedance, which any decent desktop amp provides.
| Source | HE400SE | Sundara |
|---|---|---|
| Phone / laptop jack | Plays, little or no headroom | Plays, little headroom |
| FiiO K11 R2R (single-ended, about 4 V into 32Ω) | ~9 dB headroom | ~10 dB headroom |
| Schiit Magni (Unity) (2.5 W into 32Ω, about 9 V) | ~16 dB headroom | ~17 dB headroom |
| Topping DX5 II (single-ended about 8 V into 32Ω; 6.4 W balanced) | ~15 dB headroom | ~17 dB headroom |
Headroom here is calculated from the makers’ published power ratings, not measured.
Our pick for the HE400SE: a one-box DAC/amp with about 9 dB of headroom over 110 dB peaks.
Our pick for the Sundara: a one-box DAC/amp with lots of current and a balanced output, so it keeps up as owners upgrade.
The full amp rankings are in the HE400SE amp pairing guide and the Sundara amp pairing guide .
Which Should You Buy?
Buy the HE400SE if:
- Your total budget for headphone plus amp is tight
- You are new to planars and want to try the sound
- You mostly listen to electronic, hip-hop or bass-forward music
- You want the lowest-cost route to planar bass
Buy the Sundara if:
- You can stretch the budget, or catch it on sale
- You listen to acoustic music, jazz or classical, where midrange and treble refinement show
- You are sensitive to the HE400SE’s treble peak
- You plan to keep the headphone for years
Skip both if: you need isolation (both are open-back and leak sound), or you want a headphone that sounds good straight from a phone.
The HE400SE is not a cheap substitute for the Sundara. It is a good headphone in its own right. The Sundara is the more refined one, and it does not demand a bigger amp to show it.
HiFiMAN HE400SE: See today's price for the HiFiMAN HE400SE on Amazon ↗
HiFiMAN Sundara: See today's price for the HiFiMAN Sundara on Amazon ↗
For the single-headphone write-ups, read the HE400SE review and Sundara review .
