The Softears Studio4 is 12Ω at 103.8 dB/mW; the Softears Twilight is 16Ω at 105.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The Studio4 needs 1.2 dB more than the Twilight to reach the same loudness — 0.42 mW against 0.32 mW.
| Specification | Studio4 | Twilight |
|---|---|---|
| Impedance | 12 Ω | 16 Ω |
| Sensitivity | 103.8 dB/mW | 105.0 dB/mW |
| Sensitivity (voltage) | 123.0 dB/V | 123.0 dB/V |
| Power for 100 dB | 0.42 mW | 0.32 mW |
| Voltage for 100 dB | 71 mV | 71 mV |
| Current for 100 dB | 5.9 mA | 4.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.50 Ω | 2.00 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.
5 sources are low enough in output impedance for the Twilight under the one-eighth rule but not for the Studio4 (FiiO KA13, Schiit Vali 2+, Astell&Kern HC3, 2 more).
280 of the 280 sources here reach 100 dB on both.
The Twilight is more demanding than 22% of the 567 non-electrostatic models in this database; the Studio4 than 21%.
| dB SPL | Studio4 power | Studio4 voltage | Twilight power | Twilight voltage |
|---|---|---|---|---|
| 80 | 4.2 µW | 7 mV | 3.2 µW | 7 mV |
| 85 | 0.01 mW | 13 mV | 0.01 mW | 13 mV |
| 90 | 0.04 mW | 22 mV | 0.03 mW | 22 mV |
| 95 | 0.13 mW | 40 mV | 0.10 mW | 40 mV |
| 100 | 0.42 mW | 71 mV | 0.32 mW | 71 mV |
| 105 | 1.3 mW | 0.13 V | 1.0 mW | 0.13 V |
| Source | Price | Headroom, Studio4 | Headroom, Twilight | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 14.3 dB | 16.8 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 26.4 dB | 28.9 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 23.3 dB | 25.8 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 65 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 65 is the JadeAudio JA11, at $20. It leaves 14.3 dB of headroom on the Studio4 and 16.8 dB on the Twilight, its output impedance is 0.5 Ω against a one-eighth limit of 1.50 Ω and 2.00 Ω, and its noise figure puts the hiss floor 12 dB and 12 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Studio4 | 5-40kHz (1/4' free field, -3Db) | -3 dB | 1/4″ free field |
| 20-20kHz (IEC60318-4) | not printed | IEC60318-4 | |
| Twilight | 8-40kHz(1/4' free field，-3dB) | -3 dB | 1/4″ free field |
| 20-20kHz（IEC60318-4） | not printed | IEC60318-4 |
Softears prints two ranges, “5-40kHz (1/4' free field, -3Db)” and “20-20kHz (IEC60318-4)”, for the Studio4 and two ranges, “8-40kHz(1/4' free field，-3dB)” and “20-20kHz（IEC60318-4）”, for the Twilight.
Studio4: Softears puts the tolerance on the WIDE range and leaves the effective one without it — the opposite way round to every other maker here that prints both.
Both sheets print a tolerance, which is rare enough to be worth pointing at: only 58 of the 490 models with a printed range do. These two ranges can be set against each other, because each of them says how far down the response is allowed to be at the ends.
Not a measurement; maker by maker.
Both have a page of their own. In full: Softears Studio4 and Softears Twilight. Every figure on this page comes from what Softears published, or is derived from it — what that maker publishes, counted.