Pet peeve which doesn't really affect the discussion but sealed box and acoustic suspension are not exactly the same thing. Acoustic suspension is a sealed box but with particular woofer and box size relationships. An acoustic suspension speaker is a sealed box but a sealed box need not be acoustic suspension. The old Bozak speakers were sealed box and not acoustic suspension. The famous Advent speaker was acoustic suspension.
High quality, passive, balanced, low pass crossover?
Where could I find a pair of high quality, passive, balanced, low-pass crossovers similar to Vandersteen's M7-HP? Ideally, the crossover would roll-off the signal somewhere in the range of 40 to 50Hz. The 100Hz roll-off of the M7-HP is too high for my needs. Is it possible to find one that doesn't leave a sonic footprint (i,e,. no detrimental effect on the signal going to the main speakers) - if so, where?