T60RP vs TH1100RPmk2: which needs more amplifier?

The Fostex T60RP is 50Ω at 92.0 dB/mW; the Fostex TH1100RPmk2 is 32Ω at 96.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.

The T60RP needs 4.0 dB more than the TH1100RPmk2 to reach the same loudness — 6.3 mW against 2.5 mW.

The numbers that decide it

SpecificationT60RPTH1100RPmk2
Impedance50 Ω32 Ω
Sensitivity92.0 dB/mW96.0 dB/mW
Sensitivity (voltage)105.0 dB/V110.9 dB/V
Power for 100 dB6.3 mW2.5 mW
Voltage for 100 dB0.56 V0.28 V
Current for 100 dB11.2 mA8.9 mA
Highest source impedance
that leaves them alone (one-eighth rule)
6.25 Ω4.00 Ω
Sources that reach 100 dB
out of 280
280280

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 T60RP under the one-eighth rule but not for the TH1100RPmk2 (Shanling H5).

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

What each one needs from 80 to 105 dB

The T60RP is more demanding than 88% of the 567 non-electrostatic models in this database; the TH1100RPmk2 than 72%.

dB SPLT60RP powerT60RP voltageTH1100RPmk2 powerTH1100RPmk2 voltage
800.06 mW56 mV0.03 mW28 mV
850.20 mW100 mV0.08 mW50 mV
900.63 mW0.18 V0.25 mW90 mV
952.0 mW0.32 V0.79 mW0.16 V
1006.3 mW0.56 V2.5 mW0.28 V
10520 mW1.00 V7.9 mW0.50 V

The cheapest source that satisfies both

SourcePriceHeadroom, T60RPHeadroom, TH1100RPmk2Output impedanceNoise
JadeAudio JA11$204.8 dB10.8 dB0.5 Ω1.7 µV
FiiO KA11$2913.1 dB19.0 dB0.7 Ω1.7 µV
FiiO BTR11$364.8 dB10.8 dB0.5 Ω8.0 µV

Of the 280 sources here, 280 reach 100 dB on both. 70 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 70 is the JadeAudio JA11, at $20. It leaves 4.8 dB of headroom on the T60RP and 10.8 dB on the TH1100RPmk2, its output impedance is 0.5 Ω against a one-eighth limit of 6.25 Ω and 4.00 Ω, and its noise figure puts the hiss floor 30 dB and 24 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
T60RP15 to 35,000 Hznot printednot printed
TH1100RPmk210 – 40,000 Hznot printednot printed

Fostex prints 15 to 35,000 Hz for the T60RP and 10 – 40,000 Hz for the TH1100RPmk2.

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: Fostex T60RP and Fostex TH1100RPmk2. Every figure on this page comes from what Fostex published, or is derived from it — what that maker publishes, counted.

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