Options for reducing wifi interference?

I've been adding a bunch of home automation, and recently noticed the audio through my sonos and my Astro a50s increasingly flutters and cuts out. My assumption is there's too many devices in the room/house.

Is there any simple solution. I tried google for my options, but left feeling unsatisfied, so I figured I'd give the tech board a try.

In the room with the particular issues I have 4 philips hue lights, a ps4, Sony Bravia, sonos 3.1, macpro, MacBook Air, iPhone, iPad, synology nas, airport extreme, and the a50's. Other wireless devises in the house are 2 ecobee3s, about 25 hue lights, and additional MacBooks and iPhones.

I also noticed several networks from surrounding neighbors. (Surprisingly, a couple are unsecured, so I assume they're happy to let the neighbors Use their network for overflow devices)

My first instinct is to hardwire a combination of/all of: sonos,PS4, macpro, and TV. I'm using a nighthawk 1900 router, and it only has four ports. With the AirPort Extreme in bridge mode, will the four ports act/be equivalent to a router switch?

Or should simply assigning ports and the 2.4/5ghz to specific devices potentially remedy the issue?