My experience with BOSE amp designs is that they run sub-ohm output impedances <0.5 Ohm and not the usual 2-4 Ohm on other amps. This will have a serious effect on external cross-over's frequency response designed for the usual 2-4 Ohm impedances.

There are some easy ways determining the specs of a speaker using an audio signal generator, AC voltmeter, sealed box with opening for speaker etc. if you have this equipment at hand.