Tangzu Tianpeng: how much amplifier do you need?

The Tangzu Tianpeng is 9.8Ω. Its maker prints a sensitivity of 104.0 dB and never says whether that is per milliwatt or per volt, so this page reads it as per milliwatt — on that reading it needs 0.40 mW to reach 100 dB SPL, or 62 mV across the drivers. If the figure is really per volt, it needs far more.

That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 279 have at least 10 dB of headroom and another 1 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.

The two numbers that decide everything

Impedance9.8 Ω
Sensitivity (printed with no reference unit)104.0 dB
Sensitivity (voltage) (if the figure is per milliwatt)124.1 dB/V
Power for 100 dB SPL (if the figure is per milliwatt)0.40 mW
Voltage for 100 dB SPL (if the figure is per milliwatt)62 mV
TypeIn-ear monitor
Easy to drive — anything will do it
All 280 sources at 100 dB SPL into 9.8Ω
Comfortable 279Enough 1Marginal 0Not enough 0
Cheapest portable source that does it
$9 · USB dongle · +14 dB headroom
Cheapest desktop amp with 10 dB to spare
$75 · desktop DAC/amp · +21 dB headroom

This maker printed a decibel figure and no reference unit, so the number above is shown exactly as printed. Everything below reads it as per milliwatt, which is the commoner convention on a sheet that omits the unit — if it is really per volt, this headphone is about 20 dB harder to drive than the rest of this page assumes. The converter explains the difference.

Where this sensitivity figure comes from

Tangzu publishes a sensitivity of 104 dB and does not state whether that is per milliwatt or per volt — the spec sheet simply stops at the number.

Both readings are given here so you can judge for yourself. If that 104 dB is per milliwatt, the figures on this page are right as they stand. If it is per volt, the real sensitivity is 83.9 dB/mW — 20 dB lower at 9.8Ω — and everything above understates what these need by that much. The per-milliwatt reading is the one shown, because it is the more common convention on a spec sheet that omits the unit; treat it as an indication rather than a specification.

Tangzu prints the impedance as 9.8Ω 1kHz±20%, not as a bare number. Everything on this page is calculated with the nominal 9.8Ω, and the rest of that line is quoted here rather than tidied away, because how a figure is qualified is part of the specification too.

Source: tangzu.net. How this data was built.

What is printed there, and what it is worth

As it is labelledAs printedToleranceStandard
Frequency range20Hz-20kHznot printednot printed

Tangzu prints 20Hz-20kHz for the Tangzu Tianpeng, under the heading “Frequency range”. Source: tangzu.net.

No tolerance is printed with it, so “20Hz-20kHz” says nothing about how loud this headphone actually is at 20 Hz.

Only what the maker printed; maker by maker.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.01 mW11 mV1.1 mA
95 dB SPLnormal listening0.13 mW35 mV3.6 mA
100 dB SPLloud listening0.40 mW62 mV6.4 mA
105 dB SPLvery loud1.3 mW0.11 V11.3 mA
110 dB SPLpeaks on dynamic music4.0 mW0.20 V20.2 mA

Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.

The cheapest sources that drive them with room to spare

The 15 cheapest of the 280 sources here that reach 100 dB SPL into 9.8Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.

SourceTypePricePower into 9.8ΩHeadroomVerdict
FiiO SnowSky Tiny AUSB dongle$2228 mW+18 dBComfortable
FiiO SnowSky Tiny BUSB dongle$2242 mW+20 dBComfortable
Tanchjim Stargate IIUSB dongle$4050 mW+21 dBComfortable
ddHiFi TC35ALUSB dongle$4664 mW+22 dBComfortable
ddHiFi TC35AirUSB dongle$4664 mW+22 dBComfortable
Fosi Audio N3Bluetooth receiver$5042 mW+20 dBComfortable
Hidizs SD2USB dongle$5021 mW+17 dBComfortable
iFi GO linkUSB dongle$5921 mW+17 dBComfortable
Kiwi Ears Allegro ProUSB dongle$6021 mW+17 dBComfortable
ddHiFi TC35Pro (Mountain2)USB dongle$6620 mW+17 dBComfortable
DUNU DTC 480USB dongle$7020 mW+17 dBComfortable
EPZ TP35 ProUSB dongle$7034 mW+19 dBComfortable
Aiyima A2 Prodesktop DAC/amp$7546 mW+21 dBComfortable
ddHiFi TC35Pro (Eye2)USB dongle$7620 mW+17 dBComfortable
ddHiFi TC44 Pro E2USB dongle$9977 mW+23 dBComfortable

The three ways a source goes wrong

Hiss. At 124.1 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 32 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.

Output impedance. At 9.8Ω these want a source output impedance below 1.23Ω to satisfy the one-eighth rule; 46 of the 192 sources that publish one miss it. Check yours here.

Similar headphones

Compared with its stablemates: vs Fudu Verse 1 · vs Li Zhi · vs The King Wukong · vs Xuan Nv · vs Zetian Wu.

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