Denon PMA-600NE with DALI Oberon 1: 86 dB per 2.83 V is not 86 dB per watt
The German named pairing for the smallest bookshelf in the Oberon line: 99.3 dB at two and a half metres. The pearl is arithmetic — reading the sensitivity in the wrong base is worth exactly as much as fifteen extra watts, and for a reason that is not a coincidence.
99.3 dB at two and a half metres — and reading the sensitivity in the wrong base is worth exactly as much as fifteen extra watts.
Level. DALI publishes 86 dB at 2.83 V/1 m. Into 8 Ω, 2.83 V is exactly one watt, which is why the two scales get confused; into this speaker's 6 Ω it is 1.33 W. Converting honestly gives 84.75 dB per watt — 1.25 dB below the printed figure. With the Denon's 45 W:
| Distance | Continuous SPL | Against 105 dB |
|---|---|---|
| 1 m | 101.3 dB | −3.7 dB |
| 2 m | 95.3 dB | −9.7 dB |
| 2.5 m | 99.3 dB | −11.7 dB |
| 3 m | 91.7 dB | −13.3 dB |
Enough for the small room these are bought for, and never close to reference. That is the whole honest answer to «welcher Verstärker für DALI Oberon 1».
Impedance and cable. No dip is published, so the estimate is 4.8 Ω against the Denon's 4 Ω minimum. Fifteen feet of 16 AWG costs 2 % of the voltage and leaves a damping factor of 35.
The pearl: the base error and the upgrade are numerically the same thing. Read 86 dB as if it were per watt and this page reads 94.6 dB instead of 99.3. Put a 60 W WiiM Amp Pro on the same speakers and it also reads 94.6 dB. That is not a coincidence: 10·lg(8/6) and 10·lg(60/45) are the same 1.25 dB, because 8/6 and 60/45 are the same ratio. A reader who mistakes the sensitivity scale gains on paper exactly the amplifier upgrade they were weighing — and hears none of it. The error always runs in the same direction, too: towards «the amplifier will be enough».