If your system seems to lack that "mid-bass" punch, you may need some MBMs (which is short for "music-bass modules" or "mid-bass modules").
The GSG "Roundover Series" MBM's are designed to complement theMarty Sub V2.0 Roundover line-up aesthetically. The Roundover MBM-18 has the same width and depth as the Marty Sub V2.0line-up as well as the same height as the Roundover Marty Cube. The 21" MBM is the same size as the 21" Roundover Marty Cube.
The Roundover MBM-18 is tuned to 27Hz and works great with a number of pro-audio drivers (Dayton PA460, LaVoce SAF184.03, etc.)
The Roundover MBM-21 is tuned to 28Hz and kicks up the output. It works great with a number of 21" pro-audio drivers. At this time, we recommend the LaVoce SAN214.50.