The Audeze LCD-4 is 200Ω at 97.0 dB/mW; the Audeze LCD-MX4 is 20Ω at 105.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The LCD-4 needs 8.0 dB more than the LCD-MX4 to reach the same loudness — 2.0 mW against 0.32 mW.
| Specification | LCD-4 | LCD-MX4 |
|---|---|---|
| Impedance | 200 Ω | 20 Ω |
| Sensitivity | 97.0 dB/mW | 105.0 dB/mW |
| Sensitivity (voltage) | 104.0 dB/V | 122.0 dB/V |
| Power for 100 dB | 2.0 mW | 0.32 mW |
| Voltage for 100 dB | 0.63 V | 80 mV |
| Current for 100 dB | 3.2 mA | 4.0 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 25.00 Ω | 2.50 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.
19 sources are low enough in output impedance for the LCD-4 under the one-eighth rule but not for the LCD-MX4 (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 16 more).
3 sources stay below the audible-hiss threshold with the LCD-4 but cross it with the LCD-MX4 (FiiO BTR11, Rupert Neve RNHP, Schiit Mjolnir 3).
280 of the 280 sources here reach 100 dB on both.
The LCD-4 is more demanding than 92% of the 567 non-electrostatic models in this database; the LCD-MX4 than 25%.
| dB SPL | LCD-4 power | LCD-4 voltage | LCD-MX4 power | LCD-MX4 voltage |
|---|---|---|---|---|
| 80 | 0.02 mW | 63 mV | 3.2 µW | 8 mV |
| 85 | 0.06 mW | 0.11 V | 0.01 mW | 14 mV |
| 90 | 0.20 mW | 0.20 V | 0.03 mW | 25 mV |
| 95 | 0.63 mW | 0.36 V | 0.10 mW | 45 mV |
| 100 | 2.0 mW | 0.63 V | 0.32 mW | 80 mV |
| 105 | 6.3 mW | 1.12 V | 1.0 mW | 0.14 V |
| Source | Price | Headroom, LCD-4 | Headroom, LCD-MX4 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 3.8 dB | 17.7 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 12.1 dB | 28.5 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 8.9 dB | 25.4 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 67 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 67 is the JadeAudio JA11, at $20. It leaves 3.8 dB of headroom on the LCD-4 and 17.7 dB on the LCD-MX4, its output impedance is 0.5 Ω against a one-eighth limit of 25.00 Ω and 2.50 Ω, and its noise figure puts the hiss floor 31 dB and 13 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| LCD-4 | 5Hz - 50kHz | not printed | not printed |
| LCD-MX4 | 10Hz - 50kHz | not printed | not printed |
Audeze prints 5Hz - 50kHz for the LCD-4 and 10Hz - 50kHz for the LCD-MX4.
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: Audeze LCD-4 and Audeze LCD-MX4. Every figure on this page comes from what Audeze published, or is derived from it — what that maker publishes, counted.