Abstract: A phase coherent low frequency dynamic woofer type loud speaker has a shallow depth convex cone diaphragm peripherally secured to a loud speaker support frame at one face. A ring permanent magnet is disposed behind the convex cone encircling a concentrically disposed smaller diameter pole piece. A tubular voice coil is centrally secured to the internal face of the vibrating cone and is disposed in the annular free channel volume space between the concentric circular pole piece and the inner circular volume of the permanent magnet. A flat back plate adaptively is secured to the pole piece and the permanent magnet in a concentric array. The back plate, pole piece, ring magnet and top plate form a magnet assembly which in one embodiment is removable as a unit from the speaker support. Multiple structural frame supports having a triangular cross-section extend radially connectively to the exterior loud speaker mounting frame.