I have a pair of Klipsch corner horns, just the bass section. The go to about 40 Hz and at 106 dB/1w are effective for most listening. I would not add a sub, but built one anyway.
I call the Klipsch "subs" because that seems to be the vernacular.
I do have a sub-sub, which is a 14' transmission line with 4 15s. Three of those. TLs are narrow band but efficient. I can't measure the SPL but it should be flat to 4 Hz and judging from vertical floor movement, about 5.2 Richter. Good for rocket launches, end of world movies and such. Maybe some music.
I call the Klipsch "subs" because that seems to be the vernacular.
I do have a sub-sub, which is a 14' transmission line with 4 15s. Three of those. TLs are narrow band but efficient. I can't measure the SPL but it should be flat to 4 Hz and judging from vertical floor movement, about 5.2 Richter. Good for rocket launches, end of world movies and such. Maybe some music.