Nothing will change within the cabinet—speakers will still be in, and used in some cases.The speaker enclosure is designed for the spec's of the speaker in it. If you have 2 speakers in one enclosure then it will produce different sounding bass if it has 4 speakers in it and if it has 4 speakers in one enclosure then it will produce different sounding bass if it has only 2 of the speakers working.
I think an enclosure with 4 speakers but with only two of the speakers working will produce almost no bass because the speakers that are not working will seem like large holes in the enclosure.