This page does not review anything Bowers & Wilkins 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 |
|---|---|---|---|
| P7 | 22 Ω | 94.4 dB/mW | Converted from per volt |
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 |
|---|---|---|---|
| P7 | 10Hz to 20kHz | not printed | not printed |
Bowers & Wilkins prints a frequency range for the one model here whose sheet has been read.
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 Bowers & Wilkins 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 range”.
No measurement is published here — only what was printed. The whole count, maker by maker, is in the frequency response audit.
The Bowers & Wilkins P7 needs 3.6 mW and 0.28 V for a 100 dB SPL peak at 22 Ω.
280 of the 280 sources here reach 100 dB on it, 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.
Their lowest impedance is the Bowers & Wilkins P7 at 22 Ω, so a source wants an output impedance at or below 2.8 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.