Interesting. For a short time I had a crazy notion of turning the space in the riser into a giant subwoofer but figured there must be very good reasons why people were not doing it. I imagined trying to work out the correct tuning and driver ratio would be pretty bizarre for that application.

Directly vibrating the seats would be pretty cool but a buttkicker would do that cheaper and without ruining the bass with an uneducated sub design.

With great power comes Awesome irresponsibility.