Proud owner of a new 18 SGS and would like to upgrade the audio. Can you tell me what I need to order to replace front speakers and add rear bag speakers with 4 channel amplification and plug n play.

Thxs

Installed the HD14-TKIT in my 2016 road glide and have not had the radio flashed yet. I’ve had my RF dealer closest to me say it’s not needed, and two others try to sell me DSPs and line levelers when I inquire about flashing the radio. My two part question is this: Upon turning the bike on there’s a slight pop to when the radio comes on, and a slight hum or buzz when the radio is turned down to 0. Wondering if this is normal and if it goes away once the radio is flashed or should I opt for the DSP one of the dealers say I need? One reason I got the kit is because it is all “plug and play” but seems to be becoming more of a hassle. I have also turned the bass down all the way like the install video suggests until I can get it flashed. I will say it is LOUD once I’m rolling down the road I’m just afraid to really crank it up until the flash is done.