The joint spectrum center (JSC) has developed a Spectrum Simulation Testbed to model networking and spectrum aspects of wireless tactical networks. The spectrum simulation testbed uses OPNET Modeler to model a dynamic spectrum manager (DSM) technique that uses geographic position and spectral use information to assign spectrum resources to communication nodes, while maintaining a sufficient level of interference protection to and from other environmental equipment in the same band. The prototype DSM is supported by a network management capability called mobile ad-hoc network (MANET) quality of service (QoS) that determines when the prototype DSM should be invoked. This paper will demonstrate how the Spectrum Simulation Testbed can be used to assess the spectrum resources needed and utilized for wireless tactical MANETs, when two different spectrum management (SM) methodologies are employed. Current SM will be compared to a DSM technique. These comparisons will be based upon the total spectrum bandwidth utilized and the spectrum efficiency achieved.