Facing them to the rear creates a pressure wave going backwards that pulls more base and sound clarity from your front speakers. Otherwise you just end up sitting in the middle of a cross fire of speakers firing sound in all directions, not so bad in a large concert hall but very bad in small spaces with hard and soft objects eg glass and seats. The speakers end up working against each other - the cones pump sound toward each other and kind of create a cancelled out wave of pressure.
Imagine your at a concert and the band in front of you and singer on stage raised up in front of you. This is the ideal enviroment you are trying to re-create in your car as best as possible.
Mounting small tweeters in the roof above the windscreen or dash (with independant controlled volume level control) will enable you to re-create this stage more accuratly than having the singers voice coming from below your elbows somewhere.
Considering this stage effect, you wouldn't have the band and singer on stage in front while the base player and drum kit are set up behind you pumping sound into the back of your ears. This creates phase shifts in sound pressure waves and unwanted bounce back etc. in other words crap sound with wandering base that seems to pump out a muddy slow response instead of a smooth sharp punch correctly in time with the song.
Having all the sound going in the same direction as much as possible, I believe is the simplest way to explain the best envirometn for your ears to hear the song the way it was intended the day of recording.
I've been building car stereo systems for over 15 years, its been a hobby that I became slightly obsessed with
It prob isnt the best way to do it but i didnt want people to see it from the outside as the sub-box is enclosed in another box which holds all the audio gear in the back :thumbsup:
