New stereo fitted now no rear speakers?!

[Loony R]

Hey all!
Yesterday I had the standard stereo removed and a Pioneer sph-da130dab touch screen apple play thingy.
Didn’t feel confident enough to tackle it all myself specially with extra wires and surrounds etc so had the supplier do it.
Noticed last night that I now have no rear speakers whatsoever no matter what settings I mess with!
Is there a simple explanation for this?
My car in non Bose so didn’t have a sub to worry about.
Any pointers would be ace ta

 

[Loony R]

Yeah I’m going to regardless just wanted to know more before I get there

 

[dazzler]

basically the rear speakers are driven by an amp in the boot which needs to fed from your preouts on your new head unit.word of warning though even when fed from preout you will find that you have to leave your fader about 60/70% bias to the rear as the rear amp is weak.i replaced my hu with kenwood 8170 because the fitted one was the worst ever car stereo system ive heard.now the kenwood powers the fronts-new sony amp in boot powers rears and sub when i can be bothered throwing it in-great car-**** standard stereo