which 4.1 Annex Fox

Hello guys, I also got a Fox (1.2, 55 HP) a few months ago. The serial system sounds rather less with me and the basses are not clear at all. So I wanted to buy a new system (amplifier, sub, 4 loudspeakers) + radio ! But since I have very little idea in this area I need your help Can you recommend me a system ? does not necessarily spend more like 300-400 €. Like it if it has deep but clear basses and the speakers should have a gu I would like to thank the rapporteur for his excellent report.