Today, you can cheaply route the input from a mixer into a good soundcard and through VST effects like compression before sending them out to the speakers. I have read plenty of information online about how it's very damaging to your hifi speakers (even large ones with 10' woofers) if you use them in a live setting since the dynamic range is high, and a sudden burst of sound might break your speakers.
Now, just wondering (not that I will do this) but if I run the mixer through a PC like I said earlier and give it proper compression as well as limiting (to prevent damage from sudden bursts of sound), and I have a relatively strong amp and large hifi speakers, will it be safe to play live instruments like vocals, guitar, etc from it? Basically, what I'm thinking here is that using compression and a limiter will give the live sound the more "safe" and controlled qualities of recorded music (which is designed for home speakers).