LCD-i3 vs LCD-i4: which needs more amplifier?

The Audeze LCD-i3 is 20Ω at 110.0 dB/mW; the Audeze LCD-i4 is 32Ω at 110.0 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.

In amplifier terms these two are the same headphone. The gap between what they need for 100 dB is under half a decibel, which is smaller than the step between two clicks of most volume controls.

The numbers that decide it

SpecificationLCD-i3LCD-i4
Impedance20 Ω32 Ω
Sensitivity110.0 dB/mW110.0 dB/mW
Sensitivity (voltage)127.0 dB/V124.9 dB/V
Power for 100 dB0.10 mW0.10 mW
Voltage for 100 dB45 mV57 mV
Current for 100 dB2.2 mA1.8 mA
Highest source impedance
that leaves them alone (one-eighth rule)
2.50 Ω4.00 Ω
Sources that reach 100 dB
out of 280
280280

Where the two part company

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.

7 sources stay below the audible-hiss threshold with the LCD-i4 but cross it with the LCD-i3 (Grace Design m900, FiiO M33 R2R, FiiO K17, 4 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.

What each one needs from 80 to 105 dB

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 LCD-i4 is more demanding than 15% of the 567 non-electrostatic models in this database; the LCD-i3 than 9%. 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 SPLLCD-i3 powerLCD-i3 voltageLCD-i4 powerLCD-i4 voltage
801.0 µW4 mV1.0 µW6 mV
853.2 µW8 mV3.2 µW10 mV
900.01 mW14 mV0.01 mW18 mV
950.03 mW25 mV0.03 mW32 mV
1000.10 mW45 mV0.10 mW57 mV
1050.32 mW80 mV0.32 mW0.10 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.

The cheapest source that satisfies both

SourcePriceHeadroom, LCD-i3Headroom, LCD-i4Output impedanceNoise
JadeAudio JA11$2022.7 dB24.8 dB0.5 Ω1.7 µV
FiiO KA11$2933.5 dB33.0 dB0.7 Ω1.7 µV
FiiO BTR13$5930.4 dB30.0 dB0.6 Ω1.0 µV

Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 55 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 55 is the JadeAudio JA11, at $20. It leaves 22.7 dB of headroom on the LCD-i3 and 24.8 dB on the LCD-i4, its output impedance is 0.5 Ω against a one-eighth limit of 2.50 Ω and 4.00 Ω, and its noise figure puts the hiss floor 8 dB and 10 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.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
LCD-i310Hz - 50kHznot printednot printed
LCD-i410Hz - 50kHznot printednot printed

Audeze prints the same thing for both the LCD-i3 and the LCD-i4: 10Hz - 50kHz.

Neither range has a tolerance printed beside it, and that is the whole of what this section can tell you. The two sheets print the same range, which is itself a hint about how much the number is worth. A ±dB figure is what turns a range into a specification, and of the 490 models whose maker prints a range, 58 print it.

None of this is a measurement. What each maker publishes, and what it is worth, is set out in the frequency response audit.

Both pages in full

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-i3 and Audeze LCD-i4. Every figure on this page comes from what Audeze published, or is derived from it — what that maker publishes, counted.

↑