Onkyo TX-NR414 5.1-Channel Network A/V Receiver $179.99 with free shipping [Currently $238 on Amazon]

The HK 1700 looked nice (aesthetically) and I almost ordered it on 12/31 until I noticed it was severly lacking inputs (HDMI is ok but for devices that only have component out such as the Wii or legacy SACD /
DVD-Audio players etc. the HK is lacking in inputs (not a single component input as just one example).
It turned out to be blessing in disguise because the 60+ lb high end Newcastle R-972 went on sale (for one day) for $299 shipped with no tax.

Quote from JoshMcMadMac : I have 7.1 here. I would go to 7.2, but do not want to fork out for two new subs (since they would have to match!) and really do not gain much in my setup to warrant the need for a second subwoofer.

I'm new to the surround sound family, just pulled the trigger on an Onkyo 7.1 system. Why do the subs have to be the same? By same do you mean complete specs or housing so that the delivery is the same? Does it have to do with the feed?

Lastly, how do you go about integrating the .2? (I can look up more details later, just looking for a layman term response for this.)