I'm using my TLine Array down to 80 Hz and a folded horn sub below that. Using an array for a sub entails a whole buch of at least eight inch drivers, while the folded horn uses a single eight to get the same SPL, so from a space and cost standpoint the horn makes more sense as a sub. From 80 Hz and up where you can use a lot of small inexpensive drivers and have a cabinet that's not very large the array is the better choice for my livingroom.