The Audeze LCD-1 is 16Ω at 99.0 dB/mW; the Audeze LCD-4Z is 15Ω at 98.0 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 LCD-4Z needs 1.0 dB more than the LCD-1 to reach the same loudness — 1.6 mW against 1.3 mW.
| Specification | LCD-1 | LCD-4Z |
|---|---|---|
| Impedance | 16 Ω | 15 Ω |
| Sensitivity | 99.0 dB/mW | 98.0 dB/mW |
| Sensitivity (voltage) | 117.0 dB/V | 116.2 dB/V |
| Power for 100 dB | 1.3 mW | 1.6 mW |
| Voltage for 100 dB | 0.14 V | 0.15 V |
| Current for 100 dB | 8.9 mA | 10.3 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.00 Ω | 1.88 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.
3 sources are low enough in output impedance for the LCD-1 under the one-eighth rule but not for the LCD-4Z (Astell&Kern HC3, RME Fireface UFX II, RME Fireface UFX III).
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.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Audeze LCD-1 and Audeze LCD-4Z. Every figure on this page comes from what Audeze published, or is derived from it — what that maker publishes, counted.