I’ve finally found an excellent phone app that will give me multi band equalization for my Sonos speakers. The Neutron Music Player app allows me to play audio from Phone/NAS etc to Sonos over my home wifi network including any equalization settings.

Its a bit complicated ‘tiil you get used to it and I did have to change one setting to allow quicker discovery of the Sonos speakers: Settings/Network/Source State Check Time=1

Also really good for headphones with AutoEQ built in and separate EQ for left and right ear if reqd.