The reason there are rear-firing tweeters has to do with human hearing/perceptual rules.
When the ear hears a sound, the brain makes a copy of the sound and then looks for sounds that might be similar. If it finds one, it does a comparison and looks for differences. This is part of the brain's processing to sort out where the sound is coming from.
Essentially what is happening here is the speaker designer is taking advantage of the brain's processing by providing short-delay echo information. The result is that you get improved imaging and soundstage, because the brain is better able to sort out from where the sounds appears to be coming. So its not *just* for better polar response!
When the ear hears a sound, the brain makes a copy of the sound and then looks for sounds that might be similar. If it finds one, it does a comparison and looks for differences. This is part of the brain's processing to sort out where the sound is coming from.
Essentially what is happening here is the speaker designer is taking advantage of the brain's processing by providing short-delay echo information. The result is that you get improved imaging and soundstage, because the brain is better able to sort out from where the sounds appears to be coming. So its not *just* for better polar response!