One of the things to consider in a large room is, unless you listen nearfield, most of the sound that reaches your ears will be reverberant sound. So the speaker's off-axis performance will play a larger role in the perceived tonal balance than you're probably used to.
Unfortunately, most small speakers are designed to be listened to up close, like in a small room, so the designer probably paid more attention to the on-axis sound than to what's happening off-axis. But if the radiation pattern is fairly uniform (doesn't have major off-axis flares and valleys), that's bodes well for good sound in a large room.
Another potential issue is maintaining good dynamic contrast. Speakers have to play louder to do a decent job of filling a large room, and as they play louder their voice coils heat up, and that in turn causes thermal compression which reduces their dynamic contrast. For a high fidelity application, I like to have speakers that can hit the anticipated peaks at about 1/10th their rated long-term power handling. That gets harder to do with small speakers, which typically have more modest power handling to begin with, and then trade off efficiency for bass extension.
Your secret weapon here is your decision early on to use subwoofers. This frees you up to seek out satellite speakers that may only go down to 80 Hz or so, but they will generally be higher efficiency than same-size speakers that go down deeper. Of course you don't "need" as much headroom as I described above, but imo good dynamic contrast contributes a lot to the experience. So don't seek out satellites that have a lot of bass extension you don't need, because you'll be paying a penalty in efficiency - and thus most likely in dynamic contrast - for that surplus low end.
Duke
dealer/manufacturer
