The 64 Audio Ocean is 9.5Ω at 103.7 dB/mW; the 64 Audio U6t is 9Ω at 98.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The U6t needs 5.7 dB more than the Ocean to reach the same loudness — 1.6 mW against 0.43 mW.
| Specification | Ocean | U6t |
|---|---|---|
| Impedance | 9.5 Ω | 9 Ω |
| Sensitivity | 103.7 dB/mW | 98.0 dB/mW |
| Sensitivity (voltage) | 123.9 dB/V | 118.5 dB/V |
| Power for 100 dB | 0.43 mW | 1.6 mW |
| Voltage for 100 dB | 64 mV | 0.12 V |
| Current for 100 dB | 6.7 mA | 13.3 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 1.19 Ω | 1.12 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.
4 sources stay below the audible-hiss threshold with the U6t but cross it with the Ocean (FiiO BTR11, FiiO K11 R2R, Lake People G111 Mk II, 1 more).
280 of the 280 sources here reach 100 dB on both.
The U6t is more demanding than 39% of the 567 non-electrostatic models in this database; the Ocean than 19%.
| dB SPL | Ocean power | Ocean voltage | U6t power | U6t voltage |
|---|---|---|---|---|
| 80 | 4.3 µW | 6 mV | 0.02 mW | 12 mV |
| 85 | 0.01 mW | 11 mV | 0.05 mW | 21 mV |
| 90 | 0.04 mW | 20 mV | 0.16 mW | 38 mV |
| 95 | 0.13 mW | 36 mV | 0.50 mW | 67 mV |
| 100 | 0.43 mW | 64 mV | 1.6 mW | 0.12 V |
| 105 | 1.3 mW | 0.11 V | 5.0 mW | 0.21 V |
| Source | Price | Headroom, Ocean | Headroom, U6t | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 13.2 dB | 7.3 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 25.3 dB | 19.4 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 22.2 dB | 16.3 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 58 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 58 is the JadeAudio JA11, at $20. It leaves 13.2 dB of headroom on the Ocean and 7.3 dB on the U6t, its output impedance is 0.5 Ω against a one-eighth limit of 1.19 Ω and 1.12 Ω, and its noise figure puts the hiss floor 11 dB and 17 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Ocean | 5 Hz – 22 kHz | not printed | not printed |
| U6t | 20hz – 20kHz | not printed | not printed |
64 Audio prints 5 Hz – 22 kHz for the Ocean and 20hz – 20kHz for the U6t.
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: 64 Audio Ocean and 64 Audio U6t. Every figure on this page comes from what 64 Audio published, or is derived from it — what that maker publishes, counted.