The Fostex T40RP MK3 is 50Ω at 91.0 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 T40RP MK3 needs 5.0 dB more than the TH1100RPmk2 to reach the same loudness — 7.9 mW against 2.5 mW.
| Specification | T40RP MK3 | TH1100RPmk2 |
|---|---|---|
| Impedance | 50 Ω | 32 Ω |
| Sensitivity | 91.0 dB/mW | 96.0 dB/mW |
| Sensitivity (voltage) | 104.0 dB/V | 110.9 dB/V |
| Power for 100 dB | 7.9 mW | 2.5 mW |
| Voltage for 100 dB | 0.63 V | 0.28 V |
| Current for 100 dB | 12.6 mA | 8.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 6.25 Ω | 4.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
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 T40RP MK3 under the one-eighth rule but not for the TH1100RPmk2 (Shanling H5).
280 of the 280 sources here reach 100 dB on both.
The T40RP MK3 is more demanding than 92% of the 567 non-electrostatic models in this database; the TH1100RPmk2 than 72%.
| dB SPL | T40RP MK3 power | T40RP MK3 voltage | TH1100RPmk2 power | TH1100RPmk2 voltage |
|---|---|---|---|---|
| 80 | 0.08 mW | 63 mV | 0.03 mW | 28 mV |
| 85 | 0.25 mW | 0.11 V | 0.08 mW | 50 mV |
| 90 | 0.79 mW | 0.20 V | 0.25 mW | 90 mV |
| 95 | 2.5 mW | 0.35 V | 0.79 mW | 0.16 V |
| 100 | 7.9 mW | 0.63 V | 2.5 mW | 0.28 V |
| 105 | 25 mW | 1.12 V | 7.9 mW | 0.50 V |
| Source | Price | Headroom, T40RP MK3 | Headroom, TH1100RPmk2 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 3.8 dB | 10.8 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 12.1 dB | 19.0 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 3.8 dB | 10.8 dB | 0.5 Ω | 8.0 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 3.8 dB of headroom on the T40RP MK3 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 31 dB and 24 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| T40RP MK3 | 20 to 35,000 Hz | not printed | not printed |
| TH1100RPmk2 | 10 – 40,000 Hz | not printed | not printed |
Fostex prints 20 to 35,000 Hz for the T40RP MK3 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 have a page of their own. In full: Fostex T40RP MK3 and Fostex TH1100RPmk2. Every figure on this page comes from what Fostex published, or is derived from it — what that maker publishes, counted.