WiiM Amp Ultra with Q Acoustics 3030i: 100 watts into a 75 watt speaker
The loudest bookshelf pairing in this batch — 104.8 dB at two and a half metres, and the only one that clears the reference at a metre. The amplifier also out-rates the speaker by a third, and our page stays silent about it. This one explains why, because the threshold that keeps it silent is our judgement, not anyone's datasheet.
104.8 dB at two and a half metres, and the amplifier out-rates the speaker by a third without our page saying a word.
Level. 88 dB at 2.83 V/1 m on a 6 Ω speaker converts to 86.75 dB per watt. The Ultra publishes 100 W at 8 Ω:
| Distance | Continuous SPL | Against 105 dB |
|---|---|---|
| 1 m | 106.8 dB | +1.8 dB |
| 2 m | 100.7 dB | −4.3 dB |
| 2.5 m | 104.8 dB | −6.2 dB |
| 3 m | 97.2 dB | −7.8 dB |
This is the loudest bookshelf pairing in this batch and the only one that clears the 105 dB reference at a metre.
Impedance. The 3030i publishes a 4 Ω minimum against the Ultra's 2 Ω — comfortable, and the first time in this catalogue that a 2 Ω-rated amplifier stands next to the speakers Google names it with. Fifteen feet of 16 AWG costs 2 % of the voltage and leaves a damping factor of 35.
The pearl: Q Acoustics recommends up to 75 W, the Ultra publishes 100, and this page still says nothing. Our overpower warning fires only above 1.5× the speaker's published maximum — 112.5 W here — because manufacturers' upper figures are conservative and a warning on every capable amplifier would be noise rather than information. That 1.5 is an engineering judgement of ours, not a number from anyone's datasheet, and it is the only reason 100 W into a 75 W speaker passes quietly. It is also the right way round: a 100 W amplifier driven inside its limits is safer for these tweeters than a 45 W one driven into clipping, because what kills tweeters is the high-frequency energy in a clipped waveform, not the number on the back panel.