It can start for them with a simple receiver and a small pair of speakers. A simple cable from the iPhone to RCA jacks plugged into Aux jack on the receiver.
A nice gentlemen came by for his son’s birthday and bought an older Marantz 2230 receiver and custom 2-way speakers I rebuilt with Scanspeak drivers in it.
LOL, he liked it so much during the purchase demo that he started teasing he’d give his system to his son and keep this one for himself. He called later on to share his son "loves it". Something to plug the iPhone "in to" seems to be key, fwiw. :)
I replaced that older Marantz in the garage with a new Yamaha 2-channel receiver, while not as midrange smooth, paired with some softer speakers works great too.

