LCD-2 Classic vs LCD-5s: which needs more amplifier?

The Audeze LCD-2 Classic is 70Ω at 101.0 dB/mW; the Audeze LCD-5s is 35Ω at 90.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.

The LCD-5s needs 11.0 dB more than the LCD-2 Classic to reach the same loudness — 10 mW against 0.79 mW.

The numbers that decide it

SpecificationLCD-2 ClassicLCD-5s
Impedance70 Ω35 Ω
Sensitivity101.0 dB/mW90.0 dB/mW
Sensitivity (voltage)112.5 dB/V104.6 dB/V
Power for 100 dB0.79 mW10 mW
Voltage for 100 dB0.24 V0.59 V
Current for 100 dB3.4 mA16.9 mA
Highest source impedance
that leaves them alone (one-eighth rule)
8.75 Ω4.38 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.

1 source is low enough in output impedance for the LCD-2 Classic under the one-eighth rule but not for the LCD-5s (Shanling H5).

1 source stays below the audible-hiss threshold with the LCD-5s but crosses it with the LCD-2 Classic (Schiit Mjolnir 3).

280 of the 280 sources here reach 100 dB on both.

What each one needs from 80 to 105 dB

The LCD-5s is more demanding than 90% of the 567 non-electrostatic models in this database; the LCD-2 Classic than 64%.

dB SPLLCD-2 Classic powerLCD-2 Classic voltageLCD-5s powerLCD-5s voltage
807.9 µW24 mV0.10 mW59 mV
850.03 mW42 mV0.32 mW0.11 V
900.08 mW75 mV1.0 mW0.19 V
950.25 mW0.13 V3.2 mW0.33 V
1000.79 mW0.24 V10 mW0.59 V
1052.5 mW0.42 V32 mW1.05 V

The cheapest source that satisfies both

SourcePriceHeadroom, LCD-2 ClassicHeadroom, LCD-5sOutput impedanceNoise
JadeAudio JA11$2012.4 dB4.4 dB0.5 Ω1.7 µV
FiiO KA11$2920.6 dB12.6 dB0.7 Ω1.7 µV
FiiO BTR11$3612.3 dB4.4 dB0.5 Ω8.0 µV

Of the 280 sources here, 280 reach 100 dB on both. 69 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 69 is the JadeAudio JA11, at $20. It leaves 12.4 dB of headroom on the LCD-2 Classic and 4.4 dB on the LCD-5s, its output impedance is 0.5 Ω against a one-eighth limit of 8.75 Ω and 4.38 Ω, and its noise figure puts the hiss floor 23 dB and 31 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Try any other source.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
LCD-2 Classic10Hz - 50kHznot printednot printed
LCD-5s5Hz - 50kHznot printednot printed

Audeze prints 10Hz - 50kHz for the LCD-2 Classic and 5Hz - 50kHz for the LCD-5s.

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 pages in full

Both have a page of their own. In full: Audeze LCD-2 Classic and Audeze LCD-5s. Every figure on this page comes from what Audeze published, or is derived from it — what that maker publishes, counted.

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