The Simgot EM6L is 26Ω at 103.1 dB/mW; the Simgot SuperMix 4 is 7.2Ω at 98.6 dB/mW. This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The SuperMix 4 needs 4.5 dB more than the EM6L to reach the same loudness — 1.4 mW against 0.49 mW.
| Specification | EM6L | SuperMix 4 |
|---|---|---|
| Impedance | 26 Ω | 7.2 Ω |
| Sensitivity | 103.1 dB/mW | 98.6 dB/mW |
| Sensitivity (voltage) | 119.0 dB/V | 120.0 dB/V |
| Power for 100 dB | 0.49 mW | 1.4 mW |
| Voltage for 100 dB | 0.11 V | 100 mV |
| Current for 100 dB | 4.3 mA | 13.8 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 3.25 Ω | 0.90 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.
45 sources are low enough in output impedance for the EM6L under the one-eighth rule but not for the SuperMix 4 (FiiO SnowSky Tiny B, FiiO KA13, FiiO BTR15, 42 more).
280 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
The gap between these two in decibels does not change with volume — it is a property of the two headphones. What changes is the size of the numbers, and it changes fast: every 10 dB costs ten times the power. The row that matters is the one nearest the level you listen at, and for most people that is nearer the top of this table than the bottom.
The EM6L is more demanding than 38% of the 567 non-electrostatic models in this database; the SuperMix 4 than 32%. Both figures use the same measure as the rest of the site: whichever runs out first against a 2 V, 100 mW dongle, voltage or power.
| dB SPL | EM6L power | EM6L voltage | SuperMix 4 power | SuperMix 4 voltage |
|---|---|---|---|---|
| 80 | 4.9 µW | 11 mV | 0.01 mW | 10 mV |
| 85 | 0.02 mW | 20 mV | 0.04 mW | 18 mV |
| 90 | 0.05 mW | 36 mV | 0.14 mW | 32 mV |
| 95 | 0.15 mW | 63 mV | 0.44 mW | 56 mV |
| 100 | 0.49 mW | 0.11 V | 1.4 mW | 100 mV |
| 105 | 1.5 mW | 0.20 V | 4.4 mW | 0.18 V |
105 dB is included because forum power figures are usually quoted there or higher. It is also a level that damages hearing in minutes — how many minutes is its own calculator.
| Source | Price | Headroom, EM6L | Headroom, SuperMix 4 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 17.0 dB | 6.9 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 26.3 dB | 19.0 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 18.3 dB | 11.7 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 45 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 rest either fail one of those or never printed the number at all, and 208 of them are in the second group.
The cheapest of the 45 is the JadeAudio JA11, at $20. It leaves 17.0 dB of headroom on the EM6L and 6.9 dB on the SuperMix 4, its output impedance is 0.5 Ω against a one-eighth limit of 3.25 Ω and 0.90 Ω, and its noise figure puts the hiss floor 16 dB and 15 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
Cheapest that satisfies three published numbers is not the same as best, and none of it is about how either headphone sounds. To put either model against a source this page does not mention, or to change the target loudness, use the amplifier matcher.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Simgot EM6L and Simgot SuperMix 4. Each figure on this page is labelled on those pages with where it came from, including the ones Simgot never published — what that maker publishes, counted.