Bose is just a name and the last speaker I would buy. If you like the sound of the cubes you will need to wire them directly to the receiver and pitch the sub thing if you really want to call it that and get a real sub. I would get new speakers though. If you want don't want a surround and keep...
The 1020 was designed for those with speakers system in the mid-high range. With the speaker setting to Large fronts there will be no lfe signal to the sub. The easyest fix is to change the front speaker size from large to small.