The Softears Studio4 is 12Ω at 103.8 dB/mW; the Softears Volume is 5Ω at 100.7 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The Volume needs 3.1 dB more than the Studio4 to reach the same loudness — 0.85 mW against 0.42 mW.
| Specification | Studio4 | Volume |
|---|---|---|
| Impedance | 12 Ω | 5 Ω |
| Sensitivity | 103.8 dB/mW | 100.7 dB/mW |
| Sensitivity (voltage) | 123.0 dB/V | 123.7 dB/V |
| Power for 100 dB | 0.42 mW | 0.85 mW |
| Voltage for 100 dB | 71 mV | 65 mV |
| Current for 100 dB | 5.9 mA | 13.0 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.50 Ω | 0.62 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.
49 sources are low enough in output impedance for the Studio4 under the one-eighth rule but not for the Volume (FiiO SnowSky Tiny B, FiiO KA11, JDS Labs Atom+ (2nd gen), 46 more).
1 source stays below the audible-hiss threshold with the Studio4 but crosses it with the Volume (Lake People G111 Mk II).
280 of the 280 sources here reach 100 dB on both.
The Studio4 is more demanding than 21% of the 567 non-electrostatic models in this database; the Volume than 20%.
| dB SPL | Studio4 power | Studio4 voltage | Volume power | Volume voltage |
|---|---|---|---|---|
| 80 | 4.2 µW | 7 mV | 8.5 µW | 7 mV |
| 85 | 0.01 mW | 13 mV | 0.03 mW | 12 mV |
| 90 | 0.04 mW | 22 mV | 0.09 mW | 21 mV |
| 95 | 0.13 mW | 40 mV | 0.27 mW | 37 mV |
| 100 | 0.42 mW | 71 mV | 0.85 mW | 65 mV |
| 105 | 1.3 mW | 0.13 V | 2.7 mW | 0.12 V |
| Source | Price | Headroom, Studio4 | Headroom, Volume | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 14.3 dB | 7.4 dB | 0.5 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 23.3 dB | 16.4 dB | 0.6 Ω | 1.0 µV |
| iBasso DC03 Pro | $69 | 19.5 dB | 12.6 dB | 0.12 Ω | 0.9 µV |
Of the 280 sources here, 280 reach 100 dB on both. 36 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 36 is the JadeAudio JA11, at $20. It leaves 14.3 dB of headroom on the Studio4 and 7.4 dB on the Volume, its output impedance is 0.5 Ω against a one-eighth limit of 1.50 Ω and 0.62 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 | |
| Volume | 8- 40kHz(1/4 inch free field microphone, -5 dB) | -5 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 inch free field microphone, -5 dB)” and “20- 20kHz (IEC60318-4)”, for the Volume.
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.
Volume: The tolerance Softears prints is −5 dB — a looser one than the −3 dB almost everyone else uses, and one that makes the range wider than it would otherwise be.
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 Volume. Every figure on this page comes from what Softears published, or is derived from it — what that maker publishes, counted.