The FiiO BTR11 is a Bluetooth receiver at $36. It delivers 30 mW into 32Ω and 3.0 mW into 300Ω, which ranks it 263 of 280 for raw power among the sources in this database.
Measured at 100 dB SPL it has comfortable headroom on 411 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 112, only marginal on 26 and not enough power for 18. Power is published at 16Ω, 32Ω, 300Ω; the rest of the table is derived from those figures.
The manufacturer publishes 45 mW into 16Ω, 30 mW into 32Ω, 3.0 mW into 300Ω. The rest of the table is worked out from those.
Derived rows hold output voltage steady, as an amplifier does (method).
Source: fiio.com.
| Load | Power | Status | How it was arrived at |
|---|---|---|---|
| 16 Ω | 45 mW | Published | the manufacturer publishes this figure at this exact load |
| 32 Ω | 30 mW | Published | the manufacturer publishes this figure at this exact load |
| 150 Ω | 6.2 mW | Derived | worked out between two published loads, holding output voltage linear between them |
| 300 Ω | 3.0 mW | Published | the manufacturer publishes this figure at this exact load |
| 600 Ω | 1.5 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
Easiest to hardest to drive, with headroom at a 100 dB SPL peak.
| Headphone | Impedance | Sensitivity | Needs | Headroom | Verdict |
|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 114.0 dB/mW | 0.04 mW | +28 dB | Comfortable audible hiss |
| 64 Audio U12t | 12.6 Ω | 108.0 dB/mW | 0.16 mW | +23 dB | Comfortable audible hiss |
| Shure SE215 | 17 Ω | 107.0 dB/mW | 0.20 mW | +23 dB | Comfortable audible hiss |
| Moondrop Aria | 32 Ω | 107.1 dB/mW | 0.19 mW | +22 dB | Comfortable audible hiss |
| Audeze LCD-X 2021 | 20 Ω | 103.0 dB/mW | 0.50 mW | +19 dB | Comfortable audible hiss |
| Truthear Hexa | 20.5 Ω | 103.1 dB/mW | 0.49 mW | +19 dB | Comfortable audible hiss |
| Sennheiser IE 200 | 18 Ω | 101.6 dB/mW | 0.69 mW | +18 dB | Comfortable audible hiss |
| Sony MDR-7506 | 63 Ω | 106.0 dB/mW | 0.25 mW | +18 dB | Comfortable audible hiss |
| Meze 99 Classics | 32 Ω | 103.0 dB/mW | 0.50 mW | +18 dB | Comfortable audible hiss |
| Focal Clear MG | 55 Ω | 104.0 dB/mW | 0.40 mW | +16 dB | Comfortable audible hiss |
| Philips SHP9500 | 32 Ω | 101.0 dB | 0.79 mW | +16 dB | Comfortable audible hiss |
| Focal Utopia | 80 Ω | 104.0 dB/mW | 0.40 mW | +15 dB | Comfortable audible hiss |
| Meze Empyrean | 32 Ω | 100.0 dB | 1.0 mW | +15 dB | Comfortable audible hiss |
| Campfire Audio Andromeda 2020 | 9 Ω | 94.0 dB | 4.0 mW | +8 dB | Enough audible hiss |
| Etymotic ER2SE | 15 Ω | 96.0 dB/mW | 2.5 mW | +12 dB | Comfortable audible hiss |
| AKG K371 | 32 Ω | 99.1 dB/mW | 1.2 mW | +14 dB | Comfortable audible hiss |
| Audio-Technica ATH-M50X | 38 Ω | 99.0 dB/mW | 1.3 mW | +13 dB | Comfortable audible hiss |
| Beyerdynamic DT 900 Pro X | 48 Ω | 100.0 dB/mW | 1.0 mW | +13 dB | Comfortable audible hiss |
| Audeze LCD-2 Classic | 70 Ω | 101.0 dB/mW | 0.79 mW | +12 dB | Comfortable audible hiss |
| Grado SR80x | 38 Ω | 98.0 dB/mW | 1.6 mW | +12 dB | Comfortable audible hiss |
| Sennheiser HD 560S | 120 Ω | 100.8 dB/mW | 0.83 mW | +10 dB | Enough faint hiss |
| HiFiMAN Edition XS | 18 Ω | 92.0 dB | 6.3 mW | +8 dB | Enough faint hiss |
| HiFiMAN Arya Stealth | 32 Ω | 94.0 dB | 4.0 mW | +9 dB | Enough faint hiss |
| Dan Clark Audio AEON 2 Closed | 13 Ω | 90.0 dB/mW | 10 mW | +6 dB | Enough faint hiss |
| Audeze LCD-5 | 14 Ω | 90.0 dB/mW | 10 mW | +6 dB | Enough faint hiss |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 102.0 dB/mW | 0.63 mW | +8 dB | Enough faint hiss |
| HiFiMAN HE400se | 25 Ω | 91.0 dB | 7.9 mW | +6 dB | Enough faint hiss |
| HiFiMAN Sundara | 32 Ω | 92.0 dB | 6.3 mW | +7 dB | Enough faint hiss |
| Dan Clark Audio Stealth | 23 Ω | 90.0 dB/mW | 10 mW | +6 dB | Enough faint hiss |
| Fostex T50RP MK3 | 50 Ω | 92.0 dB/mW | 6.3 mW | +5 dB | Enough faint hiss |
| AKG K702 | 62 Ω | 92.9 dB/mW | 5.1 mW | +5 dB | Enough faint hiss |
| ZMF Verite Closed | 300 Ω | 99.0 dB/mW | 1.3 mW | +4 dB | Enough faint hiss |
| Sennheiser HD 650 | 300 Ω | 97.8 dB/mW | 1.7 mW | +3 dB | Marginal faint hiss |
| Sennheiser HD 800S | 300 Ω | 96.8 dB/mW | 2.1 mW | +2 dB | Marginal faint hiss |
| Beyerdynamic DT 770 Pro (250Ω) | 250 Ω | 96.0 dB | 2.5 mW | +2 dB | Marginal faint hiss |
| Audio-Technica ATH-R70X | 470 Ω | 98.0 dB/mW | 1.6 mW | +1 dB | Marginal |
| ZMF Atrium | 300 Ω | 96.0 dB/mW | 2.5 mW | +1 dB | Marginal |
| Abyss AB-1266 Phi TC | 50 Ω | 88.0 dB/mW | 16 mW | +1 dB | Marginal |
| Sennheiser HD 600 | 300 Ω | 91.8 dB/mW | 6.6 mW | -3 dB | Not enough |
| HiFiMAN Susvara | 60 Ω | 83.0 dB | 50 mW | -5 dB | Not enough |
At 8.0 µV of output noise, here is where that noise lands in the five most revealing in-ears in the database.
This one hisses. With the most sensitive in-ears in the database its own noise lands around 39 dB SPL, which you will hear between tracks and in quiet passages.
| In-ear | Impedance | Sensitivity | Hiss level |
|---|---|---|---|
| Simgot EA500 | 16 Ω | 141.0 dB/V | 39 dB SPL |
| Tanchjim EA FORCE | 17 Ω | 137.7 dB/V | 36 dB SPL |
| Shure SE846 | 9 Ω | 134.5 dB/V | 33 dB SPL |
| Campfire Audio Clara | 13.3 Ω | 134.1 dB/V | 32 dB SPL |
| 64 Audio Fourte | 10 Ω | 134.0 dB/V | 32 dB SPL |
At 0.5Ω output impedance, the one-eighth rule says this source suits headphones of 4.0Ω and above. 1 of the 567 models here falls below that. The one model below that line is the Symphonium Titan, and the mismatch tilts the frequency response audibly rather than subtly.
| As published | FiiO BTR11 |
|---|---|
| Outputs | 3.5 mm |
| Connection | USB-C (charging only) |
| Bluetooth | BES2700IHC, Bluetooth 5.3; SBC/AAC/LDAC (amp HT97220) |
| Battery | 120 mAh |
| Battery life | ≥15 h (3.5 mm, Bluetooth AAC/SBC, 40 mV output, EQ off, 32Ω) |
| Microphone | Bluetooth calls, built-in omnidirectional mic |
| Weight | 13 g |
| Dimensions | Approximately 55 x 19 x 14.6 mm (including clip) |
Copied from the makers’ own pages: fiio.com/btr11_parameters. Battery life is the maker’s own test figure.
Nothing cheaper in this database does everything the FiiO BTR11 does. Of the 280 sources here, not one at a lower price will reach 100 dB on every headphone it reaches, stay inside the one-eighth rule wherever it does and stay under the audible-hiss threshold wherever it does. That is a plain result and it is not the usual one — most of the catalogue has something cheaper that matches it.
This counts the headphone output only; inputs, converters, the volume control and the build are outside it.
$50 · 138 mW into 32Ω · output Ω not published
Compare →$59 · 100 mW into 32Ω · 0.6 Ω out
Compare →$90 · 60 mW into 32Ω · 0.5 Ω out
Compare →$109 · 125 mW into 32Ω · 0.4 Ω out
Compare →$109 · 125 mW into 32Ω · 1.0 Ω out
Compare →$109 · 80 mW into 32Ω · 1.0 Ω out
Compare →Compared with its closest rivals: vs FiiO BTR13 · vs FiiO BTR15 · vs FiiO BTR17 · vs FiiO BTR5 2021 · vs FiiO BTR7 · vs Fosi Audio N3.