optimus, the bam module may not be what you think it is. the vsm was designed with a small volume in the woofer chamber to give the best possible mid range, to keep the efficiency up for ultra low powered tube amps, the damping up and the distortion down. we use the boost of 5.2 db at 35 hz to compensate for the loss of internal volume. the sensitivity would go down to 84 db to get the deepest bass in a large enclosure, the mids would be sounding like they came from a tunnel, the distortion would go way up and you would be on the verge of unloading the woofer constantly.
the two bandpass filters remove out of band ultra sonic information in the hf and subsonic energies below the fs of the woofer. any out of band energy beyond the res freqs cause a profound increase of im distortion in the bandwidth between. it is profoundly audible and imho, all speakers should offer this in some way.
everyone prefers it in the system. whether it is right or wrong was settled almost 20 years ago. it is designed to be used in line level signals prior to the preout stage in a tape loop or between the source and pre.
the speakers and bam are designed as a system.
ok?
thank you for your comments.