Stereo upgrade advice. 2012 Yamaha SX190

[Jnezi]

I am looking to upgrade my stereo system. Not looking to get crazy but basically replace the head unit and 4 speakers with something updated and affordable. I also would like to add 2 additional speakers back on the swim platform. After measuring space on the rear platform, it does not look like I can squeeze the 6.5 inch speakers back there. I am thinking about two 4 inch speakers.

I consider myself mechanically inclined and have installed stereos before but when it comes to amps and adding additional speakers, I am not the most qualified. I would rather not add any amps and keep it simple. Can I add two additional speakers on the rear running straight off the head unit????
What stereo/speakers would you recommend?

 

[jocolo21]

I would get waterproof water resistant head unit, fusion, Rockford fosgate something along those lines. Adding an amp is easier than what most people make it to be, adding multiple amps could be a challenge to most. For the amp +. - and remote wires, an rca from head unit to amp, from amp to your speaker easy. If you don’t want to cut glass for a sub, buy a bazooka and hide it under the seats.

 

[yjander]

Recommend fusion. I have a RA70 and it's awesome. So much better than the stock radio. I would add an amp. Even a cheaper amp is worth it. Modern speakers usually can handle at least 50 watts rms and the head units usually only push 25 max.