Car Audio Central - Ultimate Car Audio Forum and Community

Check the FAQ section for an article on rear fill

Rear fill isn't necessary. It's really your preference. Mid bass drivers will give you a definate, alternate sound.

You may be best just fading the volume more toward the front. That would really change everything without any modifications. I wouldn't give them a mono signal unless they were midbass drivers. Sending them a certain range of frequencies such as you suggested will in fact be more like midbass/midrange drivers and give similar sound as midbass drivers. The only thing you should do differently is change the high-pass frequency; I would put it more so around 80-100 Hz rather than 200.

The acoustics in vans (or SUVs) will be different as of a car or truck. This has mostly to do with subwoofer placement though; Your mainspeakers are roughly the same layout.

Welcome to the forums.

I have a Dodge full size, short wheel base, conversion van. Presently, I have a pair of 6.5 Pioneer 4-ways in front door pods. Each is angled up and in slightly, so the driver side speaker aims at the passengers left ear, and vice-versa. I also have a pair of Pioneer 6x9's up high in the rear of the van, and a pair of Pioneer 10's in 1.1 cu.ft ported boxes (what Pioneer specifies) under the rear bench seat firing upwards. I'm happy with the fronts and bass, what I'm wondering is can I do without the rear 6x9's? Are the SQ acoustics in a van similar to a car? Do I need rear fill? Would replacing them with mid-bass drivers improve things? I've read that send the rear 6x9's a mono signal, turning the volume down, relative to the fronts, and sending them a range of maybe 200 to 3000 hz would improve front staging, does this sound right?