Plug your iphone straight in. 
The Yamaha STAGEPAS 400i Portable PA System includes an eight-channel mixer/amplifier, dual two-way bass reflex speakers, two speaker cables, a power cord, 12 non-skid pads, and a cover panel. It is capable of producing up to 400-watts of output. The system has a portable design with the mixer attaching to the rear of one of the speakers for transport and storage.
The eight-channel mixer includes a variety of analog and digital input options, including two XLR inputs, two combination XLR/TRS inputs, four 1/4" instrument inputs, stereo RCA inputs, a 1/8" stereo auxiliary input, and a USB port for playing back audio from your iOS device. It has four mono channels and two mono/stereo channels, each of which has its own 2-band high and low EQs. The mixer also includes two outputs for connecting to optional monitors and an output for an optional subwoofer.
The two speakers each have an eight-inch low frequency cone driver and a one-inch voice coil compression driver. They each have a 34.8 to 35.2mm pole socket with StageLok connector to simplified set-up and breakdown.