An apparatus, comprising: a marine seismic source that includes: a first plate; a second plate substantially parallel to the first plate; a hoop disposed around an outer edge of the first and second plates (104, 150), which separates the first and second plates such that an interior cavity is formed between the first plate, the second plate and the hoop; a plurality of magnets disposed within the interior cavity between the first and second plates; and a plurality of wire coils disposed within the interior cavity between the first and second plates; wherein the hoop provides a fixed contact against which the first plate and the second plate can flex inwardly and outwardly of the interior cavity; and wherein, a magnetic field induced around ones of the wire coils is configured to interact with the magnetic field of the magnets in response to an electric current being passed through the plurality of wire coils, and the first and second plates (104, 150) are configured to flex inwardly and outwardly in a direction aligned with a central axis of the first and second plates as a result of said interaction between the induced magnetic field and the magnetic field of the magnets, and thereby to produce seismic energy; the apparatus being characterized in that: a first portion of the plurality of magnets is attached to the first plate, a second portion of the plurality of magnets is attached to the second plate, a first portion of the plurality of wire coils spatially corresponding to the second portion of the plurality of magnets is attached to the first plate, and a second portion of the plurality of wire coils spatially corresponding to the first portion of the plurality of magnets is attached to the second plate. a marine seismic source that includes: a first plate; a second plate substantially parallel to the first plate; a hoop disposed around an outer edge of the first and second plates (104, 150), which separates the first and second plates such that an interior cavity is formed between the first plate, the second plate and the hoop; a plurality of magnets disposed within the interior cavity between the first and second plates; and a plurality of wire coils disposed within the interior cavity between the first and second plates; wherein the hoop provides a fixed contact against which the first plate and the second plate can flex inwardly and outwardly of the interior cavity; and wherein, a first plate; a second plate substantially parallel to the first plate; a hoop disposed around an outer edge of the first and second plates (104, 150), which separates the first and second plates such that an interior cavity is formed between the first plate, the second plate and the hoop; a plurality of magnets disposed within the interior cavity between the first and second plates; and a plurality of wire coils disposed within the interior cavity between the first and second plates; wherein the hoop provides a fixed contact against which the first plate and the second plate can flex inwardly and outwardly of the interior cavity; and wherein, a magnetic field induced around ones of the wire coils is configured to interact with the magnetic field of the magnets in response to an electric current being passed through the plurality of wire coils, and the first and second plates (104, 150) are configured to flex inwardly and outwardly in a direction aligned with a central axis of the first and second plates as a result of said interaction between the induced magnetic field and the magnetic field of the magnets, and thereby to produce seismic energy; the apparatus being characterized in that: a first portion of the plurality of magnets is attached to the first plate, a second portion of the plurality of magnets is attached to the second plate, a first portion of the plurality of wire coils spatially corresponding to the second portion of the plurality of magnets is attached to the first plate, and a second portion of the plurality of wire coils spatially corresponding to the first portion of the plurality of magnets is attached to the second plate. a first portion of the plurality of magnets is attached to the first plate, a second portion of the plurality of magnets is attached to the second plate, a first portion of the plurality of wire coils spatially corresponding to the second portion of the plurality of magnets is attached to the first plate, and a second portion of the plurality of wire coils spatially corresponding to the first portion of the plurality of magnets is attached to the second plate.