A marine vibrator may include a containment housing, a sound radiating surface, and a compliance chamber. The compliance chamber may include a compliance chamber housing, a non-linear linkage assembly, and a low pressure chamber. The compliance chamber housing may define at least a portion of a compliance chamber internal volume having a compliance chamber internal gas pressure. The low pressure chamber may comprise a low pressure piston and a low pressure chamber housing. The low pressure chamber housing may define at least a portion of a low pressure chamber internal volume having a low pressure chamber internal gas pressure. The low pressure piston may be configured to move in response to a pressure differential across the low pressure piston such that a resonance frequency of the marine vibrator may be changed.