Touring/DSP Gang - I have some questions:
I bought this 3/99 touring from California and when it arrived in NY last October, the radio/amp/MID were not installed. The seller had mistakenly (or lazily) included non-DSP components, so over the course of a couple months, I had to sell the non-DSP stuff, source DSP stuff, fix the wiring harnesses that were hacked up to use aftermarket audio and get everything back to OEM. My only concern is that I'm not sure the little subwoofer is actually doing anything. The car also received a Bavarian Sound Works plug-&-play speaker upgrade yet still sounds marginally worse than my bone stock non-DSP 530i. The sound is kind of tinny and lacks bass, so I'm wondering if it's a faulty stock sub, or is it suppose to sound this anemic? Even with the volume turned up and my ear on the sub enclosure, I don't think anything is happening. All the connections seem intact. How should I go about troubleshooting?

Sidebar: If I decide to ignore the factory sub, While keeping stock DSP setup, what's the easiest way to add some bass without taking up space in the trunk? Have any of you gone this route? I already have a GROM unit for calls and music, just need a little bit of adult, dad "umph" in my life to fill out the cabin.
Thanks for any info.