Honestly, your arguing with hebrew hammer about SQ 101, this is dumb. Your just making yourself look stupid.You made my point. Trying to postion all the speakers to fit your listening postion in a car is impossible. Thats why HU's and EQs have these functions. You could bulid a car seat with all your speakers wrapped around your ears but we don't do that yet. Getting all the sound to reach your ears in phase "Timed" at once is impossible. Even with all the processing HU's or EQ's with sonic images being made from the stereo signal you get that center sound field where there is no speaker to start with.
Concert halls still stage speakers Front, Center, Rear and even Above, And they don't have to deal with road noise, Small cabin space etc.
If your installing "Midbass" Drivers in a threeway system which they should be if your installing them. You set your LP at 120hz or less you just removed 2/3's of there design function. They will have there own amp cause you can not add them to your Sub amp, The Xmax is to small.
Tie them to the front stage amp "Mid & Tweeters" and they sound like crap, Cause they can not play above 400hz. They are designed to play in the Bandpass response range of 100hz~400hz. If you doubt me call any quality speaker company that makes them. When setup correct you should not know where they are located. If you can the Despersion level "Timing" are setup wrong. Midbass drivers have a highier despersion level so they are less effected by location.
Now for the real fun. The installing of DVD players is making installers unlearn all these locations cause now we have to bring 5.1+ to the auto. You will now have to deal with surround sound fields.
First off, your amp comment makes no sense. Run an active setup, dedicated channels for each driver, viola, problem solved.
Secondly, "setup properly" as you put it, is ALOT more than time alignment. You can't simply place a driver wherever you want and t/a it to sounding correct. A midbass that's behind you will sound like it's behind you. The frequencies are too high, your going to draw your soundstage back. The only allowance a midbass driver will give you is that you can usually mount them off axis with no real penalty.
Lastly, while getting drivers in proper locations in a car is more or less impossible, you can get fairly close. There's a reason why kickpanels are favored over a high spot on your door panel for a midrange location... Combine that the ability to adjust phase on each driver, mounting certain drivers off axis, and controlling reflections and you can get VERY accurate soundstage within a vehicle. Anyway, I'm not sure what you meant by the "center sound field", that' supposed to be there. It should be the center of your car from either seat if you system is setup properly.
