A preferably elongated loudspeaker (LS), which preferably comprises a cylindrical moving coil (SP) and an elongated diaphragm (M) with an elongated fastening part (B) and an annular retaining part (H) lying within the fastening part (B), and with corrugations (S1) extending in radial directions, wherein the diaphragm (M) comprises an arrangement for reducing its stiffness in at least one narrow region (SM1, SM2), which arrangement is present between the fastening part (B) and the retaining part (H). In a preferred embodiment comprising an arrangement of the corrugations (S1) in the at least one narrow region (SM1, SM2) the corrugation density is smaller than the corrugation density in at least one wide region (BM1, BM2). Preferably, the diaphragm (M) furthermore comprises an additional corrugation (S2) in the at least one narrow region (SM1, SM2), which additional corrugation (S2) extends transversely to radial directions. The above measures serve to reduce the stiffness of the diaphragm (M) locally so as to minimize disadvantageous mechanical forces exerted by the diaphragm (M) on the moving coil (SP).