A marine acoustic vibrator comprising: a sound radiating surface operable to produce a resonance frequency, wherein the sound radiating surface at least partially defines a marine acoustic vibrator internal volume, wherein the marine acoustic vibrator internal volume comprises a marine acoustic vibrator internal gas having a marine acoustic vibrator internal gas pressure, wherein the sound radiating surface is operable to radiate and displace a volume of the marine acoustic vibrator internal volume; at least one compliance chamber, wherein the compliance chamber comprises: a compliance chamber internal volume, a compliance chamber piston operable to move into the compliance chamber internal volume in response to pressure variations caused by operation of the sound radiating surface that generate a force against the compliance chamber piston, and a spring function system coupled to the compliance chamber piston that provides a counteracting force against the force generated by the sound radiating surface; characterised in that it further comprises: a linear motor coupled to the compliance chamber piston operable to provide a defined force to the compliance chamber piston to reduce stiffness effects of the spring function system on movement of the compliance chamber piston in response to the pressure variations; wherein the pressure variations in the marine acoustic vibrator internal volume generated by actuation of the sound radiating surface induce the spring function system and the linear motor to adjust the compliance chamber internal volume and in turn the marine acoustic vibrator internal volume such that the pressure variations in the marine acoustic vibrator internal volume are reduced. a sound radiating surface operable to produce a resonance frequency, wherein the sound radiating surface at least partially defines a marine acoustic vibrator internal volume, wherein the marine acoustic vibrator internal volume comprises a marine acoustic vibrator internal gas having a marine acoustic vibrator internal gas pressure, wherein the sound radiating surface is operable to radiate and displace a volume of the marine acoustic vibrator internal volume; at least one compliance chamber, wherein the compliance chamber comprises: a compliance chamber internal volume, a compliance chamber piston operable to move into the compliance chamber internal volume in response to pressure variations caused by operation of the sound radiating surface that generate a force against the compliance chamber piston, and a spring function system coupled to the compliance chamber piston that provides a counteracting force against the force generated by the sound radiating surface; a compliance chamber internal volume, a compliance chamber piston operable to move into the compliance chamber internal volume in response to pressure variations caused by operation of the sound radiating surface that generate a force against the compliance chamber piston, and a spring function system coupled to the compliance chamber piston that provides a counteracting force against the force generated by the sound radiating surface; a linear motor coupled to the compliance chamber piston operable to provide a defined force to the compliance chamber piston to reduce stiffness effects of the spring function system on movement of the compliance chamber piston in response to the pressure variations; wherein the pressure variations in the marine acoustic vibrator internal volume generated by actuation of the sound radiating surface induce the spring function system and the linear motor to adjust the compliance chamber internal volume and in turn the marine acoustic vibrator internal volume such that the pressure variations in the marine acoustic vibrator internal volume are reduced.