Bose Acoustimass 7 – Passive Subwoofer (Bass Module) For sale is a passive bass module from the Bose Acoustimass 7 set. The subwoofer is fully functional from a technical standpoint. The visual condition can be seen in the photos. The front panel is yellowed and slightly warped (not perfectly straight). However, this does not affect performance – the unit works properly. The item will be carefully and professionally packed to ensure safe shipping.