The Kiwi Ears Halcyon is 29Ω at 109.0 dB/mW; the Kiwi Ears Orchestra II is 15Ω at 110.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The Halcyon needs 1.0 dB more than the Orchestra II to reach the same loudness — 0.13 mW against 0.10 mW.
| Specification | Halcyon | Orchestra II |
|---|---|---|
| Impedance | 29 Ω | 15 Ω |
| Sensitivity | 109.0 dB/mW | 110.0 dB/mW |
| Sensitivity (voltage) | 124.4 dB/V | 128.2 dB/V |
| Power for 100 dB | 0.13 mW | 0.10 mW |
| Voltage for 100 dB | 60 mV | 39 mV |
| Current for 100 dB | 2.1 mA | 2.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 3.62 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 Halcyon under the one-eighth rule but not for the Orchestra II (Astell&Kern HC3, RME Fireface UFX II, RME Fireface UFX III).
9 sources stay below the audible-hiss threshold with the Halcyon but cross it with the Orchestra II (Grace Design m900, FiiO M33 R2R, Schiit Lyr 5, 6 more).
280 of the 280 sources here reach 100 dB on both.
The Halcyon is more demanding than 17% of the 567 non-electrostatic models in this database; the Orchestra II than 6%.
| dB SPL | Halcyon power | Halcyon voltage | Orchestra II power | Orchestra II voltage |
|---|---|---|---|---|
| 80 | 1.3 µW | 6 mV | 1.0 µW | 4 mV |
| 85 | 4.0 µW | 11 mV | 3.2 µW | 7 mV |
| 90 | 0.01 mW | 19 mV | 0.01 mW | 12 mV |
| 95 | 0.04 mW | 34 mV | 0.03 mW | 22 mV |
| 100 | 0.13 mW | 60 mV | 0.10 mW | 39 mV |
| 105 | 0.40 mW | 0.11 V | 0.32 mW | 69 mV |
| Source | Price | Headroom, Halcyon | Headroom, Orchestra II | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 23.3 dB | 21.5 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 32.1 dB | 33.6 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 29.1 dB | 30.5 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 53 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 53 is the JadeAudio JA11, at $20. It leaves 23.3 dB of headroom on the Halcyon and 21.5 dB on the Orchestra II, its output impedance is 0.5 Ω against a one-eighth limit of 3.62 Ω and 1.88 Ω, and its noise figure puts the hiss floor 11 dB and 7 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Halcyon | 10-42kHz | not printed | not printed |
| Orchestra II | 20Hz-20KHz | not printed | not printed |
Kiwi Ears prints 10-42kHz for the Halcyon and 20Hz-20KHz for the Orchestra II.
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: Kiwi Ears Halcyon and Kiwi Ears Orchestra II. Every figure on this page comes from what Kiwi Ears published, or is derived from it — what that maker publishes, counted.