Dear Greg: Other than Earthquakes there are many alternatives out there.
My advise is that you go for a pair of subs ( not only one ) and one of those alternatives can be: Velodyne. In a stereo home systems it is extremely hard to beat, specially the HGS and DD series.
About to integrate subs in an audio system take a look here: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&27&4#27
Regards and enjoy the music.
Raul.
My advise is that you go for a pair of subs ( not only one ) and one of those alternatives can be: Velodyne. In a stereo home systems it is extremely hard to beat, specially the HGS and DD series.
About to integrate subs in an audio system take a look here: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&27&4#27
Regards and enjoy the music.
Raul.