Ahhh... Good ol' TA. In this case, a 4ch with a processor (BitOne, or the like) will work fine, if the time is taken to do it properly. The point, as mentioned is to have the sound from all drivers reach the listening area at the same time. Omitting the tweeters will eliminate any frequency it plays from reaching the listening area at the same time the midbass driver's does. My two cents, for what they're worth