Rca to coax cable question

Try this:

Room with cable modem

coax cable from wall to coax input on moca

coax cable from coax output of moca to coax input of Arris

ethernet cable from LAN port of Arris to ethernet port of moca

Room with Xbox

coax cable from wall to coax input on moca

cap and do not use coax output of moca

ethernet cable from port on Xbox to port on moca

Power cycle your Arris.

I have one coax cable connection and one network cable

All you do is use an adapter if you don't have a reciever to convert the coax cable to rca. The coax cable plugs into this little box and on the other end of that little box are one red and one white hole to plug rca cables out of the little box to the
TV while using the red and white plugs from the afterglow headset.

It's the hdmi setup described in the box. Go to eBay and buy the little adapter for $12-$30 or pick one up at an electronics store. It's called a digital to analog audio adapter. This I'll only produce stereo sound.

I paid $45 to get a 24bit/192kHz version

If you want to chat via the headset this is where the eBay trade in service adapters are being produced but make sure your cable fits the plug they are producing as there are two sizes depending upon the type of headset adapter.

The xbox 360 plug is a lot smaller than the aux cable that is widely used for headphones etc.

I listen and control voice / game columns on the xbox one with the headset controls.

I chat using the Kinect which no one can tell unless you about or have the TV turned up which is kinda odd if u have on headphones as the TV should be silent.

I dont know if i have a second router or if its a gateway

Good point! A gateway is basically a modem and router together.

is it a little box looking thing

A cable modem will have one coax cable connection and one network cable connection

A gateway will have one coax cable connection and 4 network cable connections

You need a "coax cable to hdmi converter." Google it, there's lots of options.