Unbearably slow Internet connection using WDS network

Question

We have an old Airport Extreme (saucer, 802.11b/g) and an Airport Express (802.11n, b/g compatible). We're using the Extreme as a WDS main, and the Express as WDS relay. Wireless devices that connect to the Internet in our house include a MacBook Pro, a couple of iPhones, an iPod Touch, an XBox 360, and a PS3.
None of these wireless devices are in direct line of sight to the main base station. Typically, our connection to the Internet is decent for the XBox, which has almost a clear line of sight to the relay (Express) base station. On the other hand, the connection for the MacBook Pro, iPhones, and iPod, is extremely slow. Maybe the actual connection speeds are the same for all devices, but at least for the XBox online gaming works. (Haven't tried online gaming with the PS3 yet.)
The problem that compelled me to post this thread is the slow Internet connection to our MacBook. When our MacBook Pro is moved from its usual location to a place just a few feet away from the Extreme, download speeds are satisfactory (e.g. 10,000+ kbps measured using Speakeasy.net). However, when we sit farther away from the Extreme and are only a few feet from the Express, download speeds are dismal (200-300 kbps). The Internet connection is noticeably slow; web pages load like molasses, and watching streaming video is almost impossible. Upload speeds are usually about 7-10x faster, which is kind of strange.
Airtunes is off. We've tried setting up the Express base station as a WDS remote instead of relay, no difference. Allow wireless clients is turned on for both main and relay. Channel 1, WPA2 personal security.
Part of the problem may be due to the fact that our house is steel framed so, depending on location, the frame of the house may get in the way of our wireless network. But even if the MacBook is within 2 feet of the Express with NO walls or obstacles in between, the speed remains dismal. The line of sight from the Extreme (main) to the Express (relay) is impeded by a few obstacles but little in the way of walls.
However, if the MacBook is close to the Extreme, with good speeds, then I walk away and sit near the Express, I still get good download speeds. This lasts only a short time. Also, if I turn off Airport on my MacBook Pro and turn it back on again, speeds are back down right away.
I understand WDS cuts the bandwidth down substantially, so I decided to unplug the Express and just use the Extreme station, set to create a wireless network instead of participate as main in a WDS network. When I do this I get satisfactory speeds on the MacBook Pro, even sitting at a location where I used to get the slow speeds.
So at first I thought forgetting about WDS completely would seem to be the solution to the problem. That seems to be true for the MacBook, but when the Express is offline and the Extreme is the only base station, the XBox and PS3 now are the devices with a very poor connection to the Internet, as there are 3+ steel framed walls between the base station and the devices. When the WDS network is up, the XBox and PS3 are almost in direct line of sight to the relay station (but then I lose speed on the MacBook and other devices.)
I'm trying to find a solution that allows a good speed connection for all these devices. Right now I have to choose between a regular network with a good connection for my MacBook, or a WDS network that allows gaming but appears to be worthless for the MacBook.
Your assistance is most welcome.

Answer 1

I'm trying to find a solution that allows a good speed connection for all these devices.
The solution is to run an Ethernet cable from the LAN port on the AirPort Extreme base station (AEBS) to the AirPort Express (AX). Then you won't need to use WDS and you won't suffer the bandwidth penalty of WDS. Then you would configure both the AEBS and AX to create a wireless network using the same SSID (network name) and wireless encryption type/level/password. The AX should be configured to act as a bridge (not sharing a single IP address).