Take a Stage, add a subwoofer underneath it,  and you have a Mini Grand. It started production in approximately 1992 and was manufactured until the demise of Apogee in 1998.

The idea was to add the low bass to the slightly bass shy Stage, but without compromising the positive attributes of the speakers itself. The additional subwoofer used two in-house produced drive units in an enclosure which sat beneath the Stage. This also acted as a stand to raise the speaker off the ground, something which helps to give more soundstage height, which the Stage is lacking compared to other Apogee's.

The addition of the external crossover meant that you need 2 power amps to drive the system, one for the Stage's and one for the subwoofers. The external crossover acted as a line level signal splitter to supply the amps powering the Stage and subwoofer with a 'filtered' signal although it does add another layer of electronics into the system