This page does not review anything AFUL makes. It counts one thing: how much of what this database says about their products came out of their own documents, and how much had to be worked out or left blank.
| Model | Impedance | Sensitivity | Source of the figure |
|---|---|---|---|
| Explorer | 26 Ω | 108.0 dB/mW | Published per mW |
| Performer 5 | 35 Ω | 110.0 dB | Unit not stated |
| Performer 8 | 30 Ω | 115.0 dB | Unit not stated |
Impedance is almost always printed. Sensitivity is the one that goes wrong, because a decibel figure means two very different things depending on whether it is per milliwatt or per volt — about five decibels apart at 300 Ω and eighteen at 16 Ω. The conversion is here.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Explorer | nothing printed | — | — |
| Performer 5 | 5Hz-35kHz | not printed | not printed |
| Performer 8 | 5Hz-35kHz | not printed | not printed |
AFUL prints a frequency range for 2 of all 3 models here whose sheets have been read, and nothing for the other 1.
Not one of those ranges comes with a tolerance in decibels. Without a ±dB figure a range says nothing about how loud the headphone is at either end of it, which puts AFUL with the majority: of the 490 models across this database whose maker prints a range, 58 print the tolerance.
Every range stands under the same heading: “Frequency Response Range”.
No measurement is published here — only what was printed. The whole count, maker by maker, is in the frequency response audit.
The hardest of the 3 to drive is the AFUL Explorer: 0.16 mW and 64 mV for a 100 dB SPL peak. Their impedances run from 26 to 35 Ω, which matters because the voltage a headphone wants rises with impedance while the power falls.
280 of the 280 sources here reach 100 dB on all 3, and the cheapest of them is the Apple USB-C dongle (EU) at $9. “Reaches” means the maker’s own published power figure is enough at that load; it is not a judgement of how it sounds.
On hiss the count is smaller, because most of the industry does not publish a noise figure at all: of the 83 sources here that do, 57 stay under the threshold of hearing on all 3 of their in-ears. The one to watch is the AFUL Performer 8 at 130 dB/V — the more sensitive the in-ear, the more of the amplifier’s own noise you hear.
Their lowest impedance is the AFUL Explorer at 26 Ω, so a source wants an output impedance at or below 3.2 Ω to satisfy the one-eighth rule on everything they make. 134 of the 169 sources that publish an output impedance manage that.
These counts use figures the source makers published themselves. A product that publishes nothing is not counted as a pass anywhere above, which is why the three numbers differ so much. The collection matcher runs the same arithmetic over whatever you actually own.