Sony: what they publish

This page does not review anything Sony 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.

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.

• Published per mW — 12: the maker prints a decibel figure per milliwatt, which is what the database stores

The hardest of the 12 to drive is the Sony MDR-Z7M2: 1.6 mW and 0.30 V for a 100 dB SPL peak. Their impedances run from 16 to 64 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 12, 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, 82 stay under the threshold of hearing on all 3 of their in-ears. The one to watch is the Sony IER-M9 at 120 dB/V — the more sensitive the in-ear, the more of the amplifier’s own noise you hear.

Their lowest impedance is the Sony MDR-1AM2 at 16 Ω, so a source wants an output impedance at or below 2.0 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.

Power decides whether it gets loud enough, output impedance decides whether it tilts the response of a multi-driver in-ear, and the noise figure decides whether you hear hiss with sensitive ones. All three fit on one line of a spec sheet; most of the industry prints one of them.

Sony publishes a power figure at a stated load on 4 of 4, output impedance on 0, a noise figure on 0. Of the 16 power figures this site displays for them at 32, 150, 300 and 600 Ω: 16 worked out by holding output voltage steady across loads.

Most of what this site says about Sony came from them, with the rest derived and labelled as derived.

The rule used here is the same for every maker and is described on the manufacturer index. Every figure behind it can be opened on the product page it came from, with the document it came from linked.

All 156 manufacturers · What the spec sheets actually say · Download the whole database