I have a four channel PPI that delivers 4 x 125RMS at 4 ohms or 4 x 250RMS at 2 ohms. I have a very nice sound in the car without a sub (I took it out last week - no room). I do have the rear speakers set up as rear fill and I might try wiring them low-pass to see if I can get them to reproduce some frequncies below what my fronts are putting out. I will try this with my JL Audio VR speakers I have in the back but I would like to know if anyone had tried this with a midbass speaker that can handle more power at low frequencies.

Anyone else tried this?? I am not exactly talking of a traditional free-air sub set-up; just something with some midbass speakers.

 

Yea, I can see it working semi-well, but are you going to be using the rear speakers just for lows? I can't see that sounding to great since you will not be getting any rear fill... Experiment, anything is possible.