HE6 Remastered vs Susvara Unveiled: which needs more amplifier?

The HiFiMAN HE6 Remastered is 50Ω at 83.5 dB (no reference unit printed); the HiFiMAN Susvara Unveiled is 45Ω at 86.0 dB (no reference unit printed). This page covers what they ask of an amplifier, not how they sound.

The HE6 Remastered needs 2.5 dB more than the Susvara Unveiled to reach the same loudness — 45 mW against 25 mW.

The numbers that decide it

SpecificationHE6 RemasteredSusvara Unveiled
Impedance50 Ω45 Ω
Sensitivity83.5 dB86.0 dB
Sensitivity (voltage)96.5 dB/V99.5 dB/V
Power for 100 dB45 mW25 mW
Voltage for 100 dB1.49 V1.06 V
Current for 100 dB29.9 mA23.6 mA
Highest source impedance
that leaves them alone (one-eighth rule)
6.25 Ω5.62 Ω
Sources that reach 100 dB
out of 280
240259

One caution before reading the rows. HiFiMAN HE6 Remastered and HiFiMAN Susvara Unveiled printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, each of them needs far more than the table says. Why the two readings differ by so much.

Where the two part company

19 of the 280 sources have the power for the Susvara Unveiled but not for the HE6 Remastered — Generic CX31993 dongles, Kiwi Ears Allegro Pro, ddHiFi TC35Pro (Mountain2), 16 more.

240 of the 280 sources here reach 100 dB on both.

What each one needs from 80 to 105 dB

The HE6 Remastered is more demanding than 99% of the 567 non-electrostatic models in this database; the Susvara Unveiled than 98%.

dB SPLHE6 Remastered powerHE6 Remastered voltageSusvara Unveiled powerSusvara Unveiled voltage
800.45 mW0.15 V0.25 mW0.11 V
851.4 mW0.27 V0.79 mW0.19 V
904.5 mW0.47 V2.5 mW0.34 V
9514 mW0.84 V7.9 mW0.60 V
10045 mW1.49 V25 mW1.06 V
105141 mW2.66 V79 mW1.89 V

The cheapest source that satisfies both

SourcePriceHeadroom, HE6 RemasteredHeadroom, Susvara UnveiledOutput impedanceNoise
FiiO KA11$294.6 dB7.5 dB0.7 Ω1.7 µV
FiiO BTR13$591.5 dB4.5 dB0.6 Ω1.0 µV
iBasso DC03 Pro$691.5 dB4.4 dB0.12 Ω0.9 µV

Of the 280 sources here, 240 reach 100 dB on both. 67 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.

The cheapest of the 67 is the FiiO KA11, at $29. It leaves 4.6 dB of headroom on the HE6 Remastered and 7.5 dB on the Susvara Unveiled, its output impedance is 0.7 Ω against a one-eighth limit of 6.25 Ω and 5.62 Ω, and its noise figure puts the hiss floor 39 dB and 36 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Try any other source.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
HE6 Remastered8 Hz - 65 kHznot printednot printed
Susvara Unveiled6Hz - 75kHznot printednot printed

HiFiMAN prints 8 Hz - 65 kHz for the HE6 Remastered and 6Hz - 75kHz for the Susvara Unveiled.

Neither range has a tolerance printed beside it, so a wider range on one sheet is not deeper bass or more treble.

Not a measurement; maker by maker.

Both pages in full

Both have a page of their own. In full: HiFiMAN HE6 Remastered and HiFiMAN Susvara Unveiled. Each figure on this page is labelled on those pages with where it came from, including the ones HiFiMAN never published — what that maker publishes, counted.

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