Those wireless links run at half or lower speed as they relay. And since there is only one non-overlapping channel on 802.11n 40MHz OFDM mode, interference is a sure thing.
Why is the modem and router so badly placed in the home?
Caveat: I've read most everything here, so I understand that bandwidth is shared among the devices in my house, that the number of users in the universe at any given time can slow things down in general, etc. I get that there are issues over which the ISP has little control. Problem is, I'm paying Suddenlink for 30 Mb of download capacity and 2 Mb of upload, and I'm getting nothing even remotely resembling those numbers. I've run speed tests the past seven days in a row (using Suddenlink's feature and an independent one, Ookla) -- one morning, one afternoon, and one evening/night. At no time am I getting a download figure higher than 2 Mb or an upload figure that doesn't begin with a zero.
I'm currently leasing an Arris modem from Suddenlink with two Netgear routers, and I've added a Netgear booster/extender in the middle of the house between the two routers. Most of the recommendations I've read are to get my own modem, but here's my question: if I switch the modem, assuming I make sure it's compatible with Suddenlink's requirements (docsis 3.0), what are the odds that'll improve my download/upload speed?