but on both my Roku, which is in a bedroom on the same floor as the Extreme, and on my LG Smart TV, which is basically directly below the Extreme one floor down, the 2.4 channel shows up as full bars excellent signal while the 5ghz shows up as mediocre
That would be because 5 GHz signals are much weaker than 2.4 GHz signals. So walls, ceilings, and any other obstruction in the signal path will absorb the 5 GHz signal much more quickly.
You have to think of 5 GHz pretty much as a "same room" or "line-of-sight" deal for good performance.
Thanks, Bob. So, the only real solution to that would be to get an Express or the like for the living room and/or bedroom?
I'm also having an issue where the light on the actual Extreme stays green, but the Internet light on AirPort Utility both on my mac and on my iPad and iPhone keeps turning orange and on my iPhone it can't even find the AirPort anymore. My ISP is horrible, but they both rewired my house and replaced my ONT this week so I'm kinda thinking it's the Extreme. Any other reason this might be happening?
And on that subject...the Alcatel-Lucent ONT they put in my basement has 4 LAN ports. They wired one to go up the side of my house into my 2nd floor study where their router had been. This is fiber run directly from the street into the ONT and they told me I could and really should replace their stock router because it's crap, the install guy uses a NetGear 750, and also I could skip the rental fees. But I'm wondering if I could just plug in another Cat5 into the ONT and hard wire my Smart TV which is in the living room right above the basement where the ONT is. Would that work?
So, the only real solution to that would be to get an Express or the like for the living room or bedroom?
Yes, but even then, 5 GHz may not "extend" well at all if you are trying to use wireless to repeat the signal. You really need to connect the AirPorts together using a wired Ethernet connection for good results.
Can't help on your other issue. Please start a new post for that.