Well, the STF-1 is a very capable 8" sub. I've spent some time with it. It offers good output and tonality. It's usable extension is limited to the upper 20Hz range, but that's still quite good for an 8" sub. It's certainly not going to knock down your 14'x13' room, but if you have reasonably modest expectations it would be fine. If you want higher output, and especially if you benefit from decent room gain, the Emotiva would likely be the way to go.