[RT-N66U] Slow internet and streaming on Wi-Fi but fast with ethernet

[AeroHI]

Hello, I bought the Asus RT-N66U since I read many reviews of how good it is. I've been using it with pretty much factory settings and the speed is very good when connected with ethernet. However, Wi-Fi speeds are very slow despite getting a strong signal; video streaming such as YouTube would constantly buffer and lag for a laptop that's in the same room as the router!

My internet plan is with Time Warner and my plan gives me up to 100 mbps download speeds which I get through devices connected with ethernet. For the laptop running on Wi-Fi in the same room as the router (5 bars of strong signal), it gets download speeds of 5 mbps or sometimes even lower. I live in a condo with many other networks, so I used inSSIDer to find the best channel for me which is 11, but still my link score is only 30 despite the computer I used to check is right next to the router. I do have at least 5 other devices connected, however they're all phones and tablets which are not active 90% of the time. Only 3 devices are usually active. Here are my wireless settings.

F/W 3.0.0.4.378_9459
H/W Ver. B1

2.4GHz
Wireless Mode > Auto (b/g protection unchecked)
Channel Bandwidth > 20MHz
Channel > 11
Authentication Method > WPA2-Personal
WPA Encryption > AES
Network Key Rotation Interval > 3600
Enable Radio > Yes
Enable Wireless Scheduler > No
Set AP Isolated > No
Roaming Assistant > Disable
Enable IGMP Snooping > Disable
Multicast Rate > Auto
Preamble Type > Short
RTS Threshold > 2347
DTIM INterval > 3
Beacon Interval > 100
Enable TX Bursting > Enable
Enable WMM APSD > Enable
Optimize AMPDU Aggregation > Disable
Optimize ack suppression > Disable
Tx power adjustment > 100%

I've tried power cycling the router and modem and today, I even tried flashing to dd-wrt with this guide but failed as I was locked out of the web UI (or maybe I didn't wait long enough).

Any help is greatly appreciated! Thank you!

 

[wouterv]

A few thoughts:
Preamble Type > Short - This is not the router default (default = Long).

What is the Wirless Mode set to (I suggest Auto)?
Do all of your wireless clients support 802.11n at 2.4 GHz?

Just to be sure: after the firmware changes, did you Restore Factory Defaults and manual configure the router or did you load an old configuration backup?

I suggest to try another Restore Factory Defaults, access the router at 192.168.1.1 with admin/admin. You shall get the setup wizzard, now manual configure the minimum required to setup your Internet access and Wireless.

The number of bars signal strenght are not a reliable measure, if there is lot of disturbance the final signal quality may be bad.
In crowded areas it may be difficult to find enough free wireless band width. Can't you try 5 GHz?

 

[AeroHI]

I was reading somewhere that the Preamble Type should be set to Short in areas with many neighboring networks and interference.
My wireless mode is set to Auto with b/g protection not checked, at 20MHz. Yes, all my devices support 802.11n. My 5 GHz remains at 20/40 MHz.

After my firmware changes, I didn't restore factory defaults because I could login with admin/admin and I manually configured the settings. But good news, after I went back to factory defaults, wireless download speeds on 2.4 GHz went up to 23 mbps. I guess it's an improvement.

I want to use 5 GHz but only devices within the same room as the router gets good signal. If I were to go into the next room, I already lose 1-2 bars. Which is why I'm afraid to lower the TX power from 100%.

I disabled QoS and other features like USB and AiCloud. What's interesting is that when I checked before when I was experiencing buffering issues, I checked my router status CPU usage and it wasn't even half maxed out. I guess it just has to do with interference and dead spots within my small condo unit.

 

[CooCooCaChoo]

You could also try reorienting your antennas to see if that will improve your situation.

 

[MarkyPancake]

My N66U is running john9527 fork and in a two storey house the 5 GHz gets to all rooms and even the rooms with 0-1 bar on the device's the Wi-Fi still works really well.

My router is in a bad location too, because at the moment it's in a room at the front of the house on the lower level and is behind a TV, which is far from ideal.

I'm now running an AC68U in the same location as the N66U and the same poorer coverage rooms still have weak 5 GHz, but work.

 

[TheManFromUncle]

On any give day there are around 30 active 2.4GHz networks where I live. Vey congested. About 4 5GHz. Needless to say, we don't use 2,4 so it's disabled. But if you're still having devices that need it, I can understand you.