Wharfedale Evo 4.4 might be 8 ohms

*nominally*. But

*technically*, they are more like 4 - 6 ohms where it really counts, in the most power hungry bass region. So, the WiiM Amp can deliver more that 60 Watts when needed. Somewhat ironically, this info is provided by Danny Richie:

gr-research.com

We can only speculate about why so many manufacturers claim their speakers beeing 8 ohms when they really should be rated as 4 ohms. The most likely reason is (once again) sensitivity numbers. 89 dB at 1 m/1 W simply means that measuring at 2.83 Volts for 8 ohm speakers. If they would stick to the more honest 4 ohms rating this would turn into 86 dB at 1 m/1 W.

It is still true that the SPL at 2.83 V RMS will be 89 dB, or course.