Fostex 4.5" full range FE126E with odd nearfield 12V application

[schn0354]

I plan on using 2 Fostex FE126E 4.5" full range drivers mounted behind the seat near shoulder level in a tractor trailer rig driven by a stock CD player/radio from a 2006 Toyota Corolla (not flashy, simple large controls, cheap). The head unit puts out about 15 watts rms per channel x 4 and should be able to drive the speakers given their high sensitivity (93dB/W(m) and being about 0.5 meters behind a listeners ears. The speakers would be mounted in a small (<1.5L) sealed or vented enclosure and somehow mounted to the back of the seat. The enclosures would be more complicated than just an MDF box.

The complexity of the design is because it must be portable and easily removed from the vehicle per company policy (i.e. less than 5 minutes to remove and carry away). I may use aluminum mounts from bicycle parts or custom build something. I am aware such a system would perform best from about 150 Hz to maybe 15KHz on axis. Larger drivers would require more space, a crossover, and could only be mounted together in a cabinet with both drivers facing forward on the floor of the cabin behind the shifter. This would also mean higher volume levels and no imaging. I plan on using the Fostex driver because almost everything in car audio is designed to work in infinite baffle, with high qts, and is not very sensitive in a small sealed enclosure.

My goal is to have low volume levels with a nearfield environment and dynamic sound that can be heard above a large diesel engine. Unfortunately, driving with an Ipod and heaphones would be dangerous.

Has anyone tried something like this?

Also, has anyone ever tried wiring a head unit's front and rear channels in series and driving an 8 ohm load (doubling the voltage and halving the current)?

Thanks for your help.
Cheers

[schn0354]

Well, unfortunately there is only a few inches of room behind the air ride seat. The speakers will have to be mounted in a cabinet on the floor behind the shifter. The each driver would have its own internal cabinet, but it would be connected by a shared wall. The whole system would be self contained, needing only a power source connection and antenna input. The front baffle would be angled in on top and maybe toed in slightly for some stereo separation. It could be built out of baltic birch plywood instead of MDF for strength.