How do I know if I need a sub woofer?

@gournard 

+1

@kofibaffour 

I have built my system based on science/physics but also with an eye (ear) toward what sounds best. I find sometimes that by going for the flattest frequency response or greatest reduction in a particular room mode, I just don't like the sound so there is always going to be that subjective aspect. But as everybody says, as long as you enjoy it, it doesn't really matter.

However, I believe you're more likely to enjoy it if you follow the science. And the science says that using multiple subwoofers will not only extend your frequency, it will also reduce your room modes. This to me is the greatest benefit. No more boomy, or at least less. Room modes are a tough cookie and to my ear, far more onerous than a less than perfectly flat frequency response.

The last few pictures in my virtual system demonstrate how multiple subwoofers not only extend the low end response but also reduce room modes and concomitant ringing. This is objective. There are subjective improvements in depth and soundstage as well.