Azure Dragon vs MT4 Pro: which needs more amplifier?

The TRN Azure Dragon is 32Ω at 108.0 dB (no reference unit printed); the TRN MT4 Pro is 40Ω at 113.0 dB (no reference unit printed). This page covers what they ask of an amplifier, not how they sound.

The Azure Dragon needs 5.0 dB more than the MT4 Pro to reach the same loudness — 0.16 mW against 0.05 mW.

The numbers that decide it

SpecificationAzure DragonMT4 Pro
Impedance32 Ω40 Ω
Sensitivity108.0 dB113.0 dB
Sensitivity (voltage)122.9 dB/V127.0 dB/V
Power for 100 dB0.16 mW0.05 mW
Voltage for 100 dB71 mV45 mV
Current for 100 dB2.2 mA1.1 mA
Highest source impedance
that leaves them alone (one-eighth rule)
4.00 Ω5.00 Ω
Sources that reach 100 dB
out of 280
280280

One caution before reading the rows. TRN Azure Dragon and TRN MT4 Pro 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

Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.

1 source is low enough in output impedance for the MT4 Pro under the one-eighth rule but not for the Azure Dragon (Shanling H5).

13 sources stay below the audible-hiss threshold with the Azure Dragon but cross it with the MT4 Pro (Lake People G103-S Mk II, Schiit Valhalla 3, Lake People G111 Mk II, 10 more).

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

What each one needs from 80 to 105 dB

The Azure Dragon is more demanding than 23% of the 567 non-electrostatic models in this database; the MT4 Pro than 9%.

dB SPLAzure Dragon powerAzure Dragon voltageMT4 Pro powerMT4 Pro voltage
801.6 µW7 mV0.5 µW4 mV
855.0 µW13 mV1.6 µW8 mV
900.02 mW23 mV5.0 µW14 mV
950.05 mW40 mV0.02 mW25 mV
1000.16 mW71 mV0.05 mW45 mV
1050.50 mW0.13 V0.16 mW80 mV

The cheapest source that satisfies both

SourcePriceHeadroom, Azure DragonHeadroom, MT4 ProOutput impedanceNoise
JadeAudio JA11$2022.8 dB26.8 dB0.5 Ω1.7 µV
FiiO KA11$2931.0 dB35.0 dB0.7 Ω1.7 µV
FiiO BTR13$5928.0 dB32.0 dB0.6 Ω1.0 µV

Of the 280 sources here, 280 reach 100 dB on both. 55 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 55 is the JadeAudio JA11, at $20. It leaves 22.8 dB of headroom on the Azure Dragon and 26.8 dB on the MT4 Pro, its output impedance is 0.5 Ω against a one-eighth limit of 4.00 Ω and 5.00 Ω, and its noise figure puts the hiss floor 12 dB and 8 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
Azure Dragon7Hz-40KHznot printednot printed
MT4 Pro20Hz-20kHznot printednot printed

TRN prints 7Hz-40KHz for the Azure Dragon and 20Hz-20kHz for the MT4 Pro.

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: TRN Azure Dragon and TRN MT4 Pro. Each figure on this page is labelled on those pages with where it came from, including the ones TRN never published — what that maker publishes, counted.

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