After looking at the manual for my Acoustimass 6 speakers, it says the following:
Left and Right front= LARGE
Left and Right Surround+ LARGE
Since I bought these speakers and they come with a subwoofer, why would I set the subwoofer as OFF? is the above the correct settings or what should they be instead?
Because you don't have an actual subwoofer plugged into your receiver's subwoofer jack. The Bose Acoustimass in not really a subwoofer, it's a speaker that carries the mid-lows that your cubes can't carry.
If you want really low frequencies that shake the house, you need to purchase an actual subwoofer that plugs into your receiver subwoofer jack and carries the very low frequencies.
I have no idea. I would follow the instructions to start. Then, maybe try some different settings to see which works best for you.
According to the specifications, your settings should be as follows:
Crossover frequency: 200 Hz
The other settings you previously referenced are likely for a speaker package with different specifications. You may find that some experimentation with the crossover frequency will get you a result more to your liking, however we list the setting that is ideal with regard to your speaker's performance in most cases.
Greg - Community Support