Hidizs S9 Pro vs Onix Alpha XI1

Short answer

  • More power: the Onix Alpha XI1, with 180 mW into 32 Ω; the Hidizs S9 Pro has 100 mW (balanced: 500 mW against 200 mW). The Onix Alpha XI1 drives 4 headphones to 100 dB that the Hidizs S9 Pro cannot (Moondrop COSMO, Moondrop PARA 2, Symphonium Helios, 1 more).
  • Hiss with sensitive IEMs: cannot be compared — the maker of the Onix Alpha XI1 publishes no noise figure.
  • Price: the same, $109.

Both are dongles, both at $109.

The Onix Alpha XI1 reaches 100 dB on 564 of the 567 models here, the Hidizs S9 Pro on 560.

Side by side

Every published figure, next to each other

SpecificationHidizs S9 ProOnix Alpha XI1
Power into 32Ω100 mW180 mW
Power into 150Ω21 mW38 mW
Power into 300Ω11 mW19 mW
Power into 600Ω5.3 mW9.6 mW
Output impedance0.3 Ω unverified0.4 Ω
Output noise4 µV unverifiednot published
Price$109$109
Headphones it reaches 100 dB on
out of 567		560564

Not published means the maker leaves it out, so that axis cannot be compared.

Balanced output

The 4.4 mm or XLR socket, rated on its own

BalancedHidizs S9 ProOnix Alpha XI1
Socket2.5mm4.4mm
Power into 32Ω200 mW500 mW
Power into 300Ω21 mW derived53 mW derived
Output impedancenot published0.8 Ω
Output noisenot publishednot published
Headphones it reaches 100 dB on
out of 567		564566

Through the balanced sockets the Onix Alpha XI1 reaches 100 dB on 566 of the 567 models here and the Hidizs S9 Pro on 564. Derived figures are worked out from the loads the maker did publish.

How solid these numbers are

Where each power figure comes from

LoadHidizs S9 ProOnix Alpha XI1
32 ΩPublishedPublished
150 ΩDerivedDerived
300 ΩDerivedDerived
600 ΩDerivedDerived

Both makers publish a power rating. Hidizs S9 Pro publishes at 32 Ω; Onix Alpha XI1 at 32 Ω. The other rows are worked out from those.

The two publish at the same loads, which is the one case where the rows of this table can be read straight across.

What the labels mean.

What separates them

The headphones that tell them apart

4 headphones reach 100 dB on the Onix Alpha XI1 but not on the Hidizs S9 Pro — Moondrop COSMO, Moondrop PARA 2, Symphonium Helios, 1 more.

560 of the 567 models here reach 100 dB on both.

On real headphones

Headroom and hiss on 8 models, both sources

Headroom is at a 100 dB SPL peak.

The widest gap on the list is the Audio-Technica ATH-R70X: Onix Alpha XI1 has +9 dB of headroom there against +6 dB. 3 dB is about 1.8 times the power, which matters for peaks rather than for how loud the music sits.

The hiss columns are empty for Hidizs S9 Pro and Onix Alpha XI1 because neither maker publishes no output noise figure.

HeadphoneImpedanceNeedsHidizs S9 Pro headroomOnix Alpha XI1 headroomHidizs S9 Pro hissOnix Alpha XI1 hiss
Shure SE8469 Ω0.04 mW+28 dB+31 dBnot publishednot published
Campfire Audio Andromeda 20209 Ω4.0 mW+8 dB+11 dBnot publishednot published
Audeze LCD-2 Classic70 Ω0.79 mW+18 dB+20 dBnot publishednot published
Beyerdynamic DT 1990 Pro (250Ω)250 Ω0.63 mW+13 dB+16 dBnot publishednot published
HiFiMAN HE400se25 Ω7.9 mW+10 dB+12 dBnot publishednot published
Audio-Technica ATH-R70X470 Ω1.6 mW+6 dB+9 dBnot publishednot published
Sennheiser HD 600300 Ω6.6 mW+2 dB+5 dBnot publishednot published
HiFiMAN Susvara60 Ω50 mW+0 dB+3 dBnot publishednot published
What the price difference buys

The gap in dollars, against the gap in numbers

These two cost the same, $109, so price settles nothing. Out of the 567 models here, the Onix Alpha XI1 drives 4 models to 100 dB — and on the other side there is no such advantage at all.

Only published figures count here; blank axes are counted separately.

Next

Both pages in full

Each in full: Hidizs S9 Pro and Onix Alpha XI1.

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