This page does not review anything Denon 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 |
|---|---|---|---|
| AH-D2000 | 25 Ω | 106.0 dB/mW | Published per mW |
| AH-D5200 | 24 Ω | 103.0 dB/mW | Published per mW |
| AH-D7200 | 25 Ω | 105.0 dB/mW | Published per mW |
| AH-D9200 | 24 Ω | 105.0 dB/mW | Published per mW |
| AH-MM400 | 40 Ω | 105.0 dB | Not published |
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 |
|---|---|---|---|
| AH-D2000 | 5 - 45,000 Hz | not printed | not printed |
| AH-D5200 | 5 - 40,000 (Hz) | not printed | not printed |
| AH-D7200 | 5 - 55,000 (Hz) | not printed | not printed |
| AH-D9200 | 5-56.000Hz | not printed | not printed |
| AH-MM400 | nothing printed | — | — |
Denon prints a frequency range for 4 of all 5 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 Denon with the majority: of the 490 models across this database whose maker prints a range, 58 print the tolerance.
The rows are not even called the same thing twice: 2 different headings across 4 models (“Frequency response”, “Playback frequencies”).
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 5 to drive is the Denon AH-MM400: 0.32 mW and 0.11 V for a 100 dB SPL peak. Their impedances run from 24 to 40 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 5, 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 Denon AH-D5200 at 24 Ω, so a source wants an output impedance at or below 3.0 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.
Most of what this site says about Denon 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.