The FiiO FT3 (32Ω) is 32Ω at 95.1 dB/mW; the FiiO FT3 (350Ω) is 350Ω at 100.4 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The FT3 (32Ω) needs 5.3 dB more than the FT3 (350Ω) to reach the same loudness — 3.1 mW against 0.91 mW.
| Specification | FT3 (32Ω) | FT3 (350Ω) |
|---|---|---|
| Impedance | 32 Ω | 350 Ω |
| Sensitivity | 95.1 dB/mW | 100.4 dB/mW |
| Sensitivity (voltage) | 110.0 dB/V | 105.0 dB/V |
| Power for 100 dB | 3.1 mW | 0.91 mW |
| Voltage for 100 dB | 0.31 V | 0.56 V |
| Current for 100 dB | 9.8 mA | 1.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 4.00 Ω | 43.75 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.
20 sources are low enough in output impedance for the FT3 (350Ω) under the one-eighth rule but not for the FT3 (32Ω) (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 17 more).
280 of the 280 sources here reach 100 dB on both.
The FT3 (350Ω) is more demanding than 89% of the 567 non-electrostatic models in this database; the FT3 (32Ω) than 76%.
| dB SPL | FT3 (32Ω) power | FT3 (32Ω) voltage | FT3 (350Ω) power | FT3 (350Ω) voltage |
|---|---|---|---|---|
| 80 | 0.03 mW | 31 mV | 9.1 µW | 56 mV |
| 85 | 0.10 mW | 56 mV | 0.03 mW | 0.10 V |
| 90 | 0.31 mW | 99 mV | 0.09 mW | 0.18 V |
| 95 | 0.98 mW | 0.18 V | 0.29 mW | 0.32 V |
| 100 | 3.1 mW | 0.31 V | 0.91 mW | 0.56 V |
| 105 | 9.8 mW | 0.56 V | 2.9 mW | 1.00 V |
| Source | Price | Headroom, FT3 (32Ω) | Headroom, FT3 (350Ω) | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 9.9 dB | 4.8 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 18.1 dB | 13.2 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 9.9 dB | 4.5 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 70 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 70 is the JadeAudio JA11, at $20. It leaves 9.9 dB of headroom on the FT3 (32Ω) and 4.8 dB on the FT3 (350Ω), its output impedance is 0.5 Ω against a one-eighth limit of 4.00 Ω and 43.75 Ω, and its noise figure puts the hiss floor 25 dB and 30 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| FT3 (32Ω) | nothing printed | — | — |
| FT3 (350Ω) | 7Hz-40kHz | not printed | not printed |
FiiO prints nothing at all for the FT3 (32Ω) and 7Hz-40kHz for the FT3 (350Ω).
FT3 (32Ω): FiiO has one FT3 page and it is the 350 Ω version: it prints "Frequency response: 7Hz-40kHz" beside "Impedance: 350Ω". No page of their own covers the 32 Ω FT3, so there is no range printed for this variant — which is not the same as FiiO printing nothing for the FT3.
So one side of this comparison has a frequency-response number and the other does not — which changes less than it looks. The range printed for the FT3 (350Ω) comes with no tolerance beside it, and a range without a ±dB figure says nothing about how loud the headphone is at either end of it: thirty decibels down at the bottom and the sentence would still be true. On the only reading that would have made it a specification, the two sheets say the same amount: nothing.
Not a measurement; maker by maker.
Both have a page of their own. In full: FiiO FT3 (32Ω) and FiiO FT3 (350Ω). Each figure on this page is labelled on those pages with where it came from, including the ones FiiO never published — what that maker publishes, counted.