David:
I guess there are two key factors at play here. At home, you have the option of moving speakers around, and you can tame reflections fairly easily. In a car, not so much. It really makes a huge difference. Even the bass is much tighter now - the one note boom is gone.
Duckman:
Here's a hint. Before you run your sweep, turn down the gain on your sub amp. Otherwise, Imprint will cut it back to the point where you can barely hear it. After you apply the corrections, turn it back up. You should have plenty of impact without the boom.
