I have only found one speaker that performs VERY well in both applications, that is the Roman Audio Centurions. They are an 8" two-way speaker that is very efficient (93db),so they don't require a ton of power. I use a set of these speakers in my two channel and my best friend uses a pair for his mains in his HT. You take the Centurions and run them along with the Pro Consul (Roman Audio center channel), you've got a serious set-up for HT. The price for the Centurions is $6K (new). Check out the web site, www.romanaudio.com