I have the Merlin VSM-M without the BAM (and have never heard one). The Merlin site states: 5.2dB of boost at 35 Hz; Subsonic bass roll-off below 27Hz. I chose not to use a BAM because I use a low power SET amp for which 5.2dB would be rather significant. I let the lows roll off naturally and add a solid state sub for the bottom down to 20Hz.
