usage wattage

Hi all , hope you can help, I've found on the Sonos site the usage wattage when idle 

https://support.sonos.com/en-gb/article/sonos-power-consumption-while-idle

BUT what I need to know is there a way of knowing how much wattage is used during playback, I know it can vary but most manufacturers put " max ...w " on the label . I need to know because I'm thinking of adding the mini sub but it would run off the same twin socket outlet as my beam 2 and 1x One SL ( also the tv , sky box and fire stick ) sky box has " max 41 watts " fire stick has  " 21 watt " stamped on the plug , tv 140 watts max but nothing on the beam or One SL. One SL has 1a on the bottom but looking at the idle watt page it wouldn't work out right at 1a , using the formula A x V = watt a one SL would use 240 watts but says 6 watts on the Sonos site .