Air-spring compensation in a piston-type marine vibrator

PGS-13-30US-12 Embodiments relate to the restriction of gas flow in a piston-type marine vibrator to compensate for air-spring effects. An embodiment provides marine vibrator comprising: a containment housing; a piston plate; a fixture coupled to the containment housing; a mechanical spring element coupled to the piston plate and to the fixture; a driver coupled to the piston plate and to the fixture; and a variable gas flow restrictor disposed in an interior volume of the marine vibrator, wherein the marine vibrator has a resonance frequency selectable based at least in part on the variable gas flow restrictor. U-) 00C> U" U'0 00-