An ultrasonic processing method and apparatus (20) can include a rotatable, ultrasonic horn member (28) that is operatively joined to an isolation member (42) which has high rigidity. Additionally, a rotatable anvil member (86) can be cooperatively positioned to provide a selected horn-anvil gap (106) between the anvil member (86) and the horn member (28). A transfer device (110) can be configured to selectively adjust the horn-anvil gap (106), and an automated drive (130) can be operatively connected to the transfer device (110) to selectively modify the horn-anvil gap (106). A force sensor (126) can be configured to detect a gap force at the horn-anvil gap (106), and an electronic processor (128) can be configured to employ an output from the force sensor (126) to monitor the gap force, and provide a drive signal to the automated drive (130) to thereby adjust the horn-anvil gap (106).