I'm reasonably sure that what you're asking for can't be done with the current empeg hardware. Here's the reason:

1. The MP3 gets decoded into two channel (left and right) wave audio.

2. That wave audio is then sent to the DSP, which is an ordinary off-the-shelf car stereo DSP, so it has only two inputs (left and right).

3. The DSP is what controls the front/rear balance and the equalization, and then sends the audio to the outputs.

I'm pretty sure that the time alignment trick is done by the kernel between steps 1 and 2. It simply delays one of the two audio channels slightly.