So I’ve received and setup both 673GRU’s using DD-WRT on 5GHz N (Channel 153/40Mhz/Short preamble). Even with the two routers separated by 1 meter, the signal strength doesn’t report that high in the status screen (only about 60%). Apparently it’s an issue on DD-WRT, where it under-reports the strength.
I managed to have my routers negotiate a 120 Mbps connection in the short distance from the base router to the client bridge. It will pull approximately 6 MB/sec peak, but unfortunately still not enough for high bitrate MKVs. I figure it might have something to do with signal strength, so I did some research.
Later in the same evening, the winds blew in a strange direction and my routers were reporting 0% signal strength, though the connection was still there but resulted in even low bitrate divx having buffering issues.
According to the DD-WRT Wiki, the DIR-825 (basically identical to the 673GRU) has the following specs:
Antenna Gain (2.4 GHz): 2 dBi
Antenna Gain (5 GHz): 2 dBi
Max TX Power (2.4 GHz): 18dBm
Max TX Power (5 GHz): 17dBm
FCC ID: KA2DIR825B1
FCC ID: XU8TEW673GRU
The 673GRU has 3 dBi antennas, so that is one setting you need to change.
Those are the max TX power settings I can set in DD-WRT, however the FCC documentation shows that 5 GHz band can get up to 25.8 dBm as long as you use the higher channels. The lower channels cap out at 15 dBm.
I need to do some more research and figure out how to unlock the extra antenna power.