Log into your extender and see what it says.

Extenders for the most part really suck and screw up a network pretty badly.

Well, got home tonight and did some testing and this is just getting stranger by the minute. Taking advice from people here (and from a Google search), first thing I did was check for a router firmware update. There was one! But alas it did nothing to remedy this problem.

Second thing I did was disconnect my two wifi extenders to see if they may be causing interference. No luck.

Third thing I did was download a wifi analyzer app on my phone to see which channels were most/least congested. My Router was set to auto and after testing I found channel 9 to be the best choice. Changed the 2.4 Ghz signal to channel 9 but still no luck, issue is persisting.

So I'm sitting in my living room (location of the first extender, which is still unplugged) and decide to speed test the 5 Ghz signal, which I'm receiving but at maybe at 3 bars out of 5. Lo and behold I get 25 Mbps speed! To make sure it's not a fluke I retest the speed in the office (location of the router) and the 5 Ghz signal is at 25 Mbps, then I retest again in the living room and its holding at 25 Ghz.

I then switch to the 2.4 Ghz signal in the living room at it's at a meager 3 Mbps. Go to the office and retest it and its at 25 Mbps. Retest in the living room, again 3 Mbps. 

So something funky is going on. Why is my 2.4 Ghz signal providing 25 Mbps in the same room as the router, but just outside the room (and anywhere else in the house) it is a lousy 3 Mbps, but the 5 Ghz signal both in the office and elsewhere in the house (where I can get it) it holds constant at 25 Mbps? Something is causing the 2.4 Ghz signal to tank as soon as you leave the room the router is in, and I can't figure out what. 

I thought the easy fix would be to have my wifi extenders connect to the 5 Ghz signal, but they seem to default to connecting and re-transmitting the 2.4 Ghz signal at a slow 3 Mbps speed, and I can't figure out how to get them to connect to the 5 Ghz signal.

First, there's only three 2.4ghz channels.  1, 6, and 11.  

Your 2.4ghz channel is using 802.11b, most likely.  See what your router has for options, if you can force it to 802.11n or 802.11g you may have better luck.  I don't know that particular router and all its options, but that's likely your problem.  It may actually be your extenders forcing the router to drop to 802.11b, most of them have compatibility settings -- if one device on the net is 802.11b, the router will drop to connect to that one and run at the slowest speed possible.  It's also possible there's another device (do you have a fitbit scale or something like that?  They're notorious for that, and why I have mine on a completely separate network) that's doing it.  Make sure that 2.4ghz radio is set to 802.11n, not "b/g/n compatible" or something like that.

I am going to start with the most obvious problem.  The "office" is really a bunker, and by bunker I mean a gun locker.  You have so many guns around you that it is acting like a faraday cage, attenuating your WiFi signal strength.  If I have done the needful and answered your question satisfactorily, please stay on the line and record your satisfaction with Raj ShingmahagenAlemahagen III.  By the way my name is Bob.

Correct, sounds like some optimization is in order. Run N only, if you can't go with G only. Don't use Auto on either channel or wave length (if optioned.) You may need to play with the channels to find a 'cleaner' one. Running in a compatibility mode will absolutely kill performance. Also, check to see if you have an after booster or similar feature, if so disable it. Lastly I would test with no security enabled; you don't want to run like this but for testing purposes it's fine. Some security modes are heavy overhead on a routers processor/ram or signal; you may need to play with various combos. I'd stick with WPA2 with AES if possible but TKIP may work better; avoid having to use WPA or god forbid WEP.

As I said in an earlier post, I'd be looking at upgrading your hardware to be happy. Consumer stuff is largely junk.

EDT...Play with the position of the router (higher is better) and the arrangement of antenna(s.)

Just checked router settings. In my router settings on the wireless page where I see settings for the 2.4 Ghz and 5 Ghz wireless networks the 2.4 Ghz it says:

Wireless Network (2.4GHz b/g/n)

and the 5 Ghz wireless network says:
Wireless Network (5GHz a/n/ac)

But I don't see any options to change the b/g/n

Look for an option that talks about "compatibility" or some such.  If the router firmware doesn't make those options available, you're going to have to reflash it with something that does -- dd-wrt or tomato probably if those are available for that router.  

nevermind -- I just read through the manual for that router.  You don't have the options to turn off compatibility mode.  You're screwed unless you can find out what's forcing it into 802.11b and either shut it off off or upgrade it.

If you do decide to put a third party solution on the router, make sure you have the right version for your *exact* router model, and make sure you can flash it back to stock.  Study first, flash second.

I have an X6, it is a great wireless router, but it didn't extend my range at all over my crappy uVerse one.  I thought it would with 6 antennas, but I am still going to have to run a Cat6a cable to my furthest bedroom to hard wire my blu ray player.

Get a Ubiquiti USG and an AP-AC-PRO. No more problems. I will never touch a linksys/asus/netgear/tp-link/etc. again. Ubiquiti's stuff is a game changer when used at home.

Suprisingly, it will also cost less than a high-end router from the manufacturers I previously mentioned. 

Thanks. Also just found out the Netgear N300 wifi extenders I bought only work on the 2.4 Ghz bandwidth, and won't pick up or relay a 5 Ghz signal. Still not sure why my 2.4 Ghz signal speed (not distance it can be reeived) is degrading so much such a short distance from the router.

Because 802.11b is max 11mb/s, which means it's really about 3, and your 2.4ghz network is running on 802.11b.  Most likely.

You brought a new device home or turned on an old device.  This is the issue.

802.11 b/g/n is limited to the speed of the slowest device connected, without regard to the speed of the fastest device connected.

Turn off Everything.  Check on the router to be certain that there isn't anything connected other than your testing device, then test.

Not sure if this is relevant, but looking at my routers wifi signals on my work laptop it shows the 5 Ghz signal is 802.11n, and the 2.4 Ghz signal is also 802.11n. So, I don't think the 2.4 Ghz signal is transmitting in 802.11b.

It may think that because that's what it's configured to do.  It probably isn't.  What are you looking at the signals with?

Looking at the connected devices on my router all are new(er) devices, but have been on my router for at least a year - my PC (which is hardwired to the router), 2 cell phones (Samsung Galaxy S5s), and 2 LG tablets. Using any of them if I'm on the 2.4 Ghz signal in the same room as the router, they get ~25 Mbps speed. But step out of the room where the router is, speed dives to 3 Mbps. 

Dell EliteBook laptop...mousing over the various wifi signals in the wireless network connection section gives info for each signal like name, signal strength, security type, radio type, and SSID.

CAT5 can run for hundreds of feet with no loss issues at all, 100ft of cable is nothing providing it's quality UTP with the twist maintained all the way to the plugs/sockets.

100 meters max.

Try this on one of the phones: Play Store. It says you can graph signal strength over time. Walk around your house starting from the office and see what it turns up signal wise.

Otherwise Josh is probably right and you want to install a different firmware. It's nothing to worry about if you can follow instructions.

Am I the first to say wireless sucks?

My docked laptop gets 150mbps up and down. There is a wireless N  access point 5 feet away from  me, I unlock the laptop, rerun the test and its half of the wired speed. No obstructions or interference, access point and dock are plugged into the same switch. Add a couple of walls and its only going to get worse.

Wireless should be avoided if you are looking for performance.

Good wireless doesn't suck.  Home stuff is crap.  And as a technology it's half duplex with a lot of "wait to talk" built in so you'll never get close to the actual data rate you're connect at.  Typically half is about as good as you can do and that's under perfect conditions with nothing else on the AP.  The more devices you add the slower it gets.

Didn't read both pages so might already be addressed but my neighborhood is saturated with wireless interference, neighbor get a new router maybe? You try switching channels? I ended up just wiring my house and running a ubiquiti ap to a couple locations.

ETA: Also I once had a ridiculous wireless problem where a turtlebeach wireless headset dongle plugged into my xbox 360 was DOSing 2.4GHZ in my living room, it was pretty insane and very repeatable.

I don't have home stuff but like I said, wireless should be avoided if you are looking for performance. thank you for bolstering my argument.

Agree. Wireless sucks if you want solid performance.run the damn cable if you want performance.