An audio generator comprising: a first transducer element comprising a membrane having a surface which is non-flat; and means for causing the membrane to move in dependence on an input signal so as to cause audio waves to propagate in a first direction (M, 300, 300A, 300B) away from said membrane; and wherein the membrane has an outer perimeter which is flexibly attached to a portion of a transducer element body ; said outer perimeter defining a first aperture having a first aperture plane ; and wherein, in operation, the membrane is adapted to cause said audio pressure waves to propagate in the first direction (M, 300, 300A,) orthogonal to said first aperture plane ; wherein said audio generator further comprises a second aperture , a reflector and directive guiding walls ; the reflector having a surface adapted to reflect acoustic signals in a second direction orthogonal to a plane of said second aperture ; said second direction being different from said first direction; wherein the acoustically reflective surface has a non-flat contour , characterized in that the reflector co-operates with the directive guiding walls so as to lead, guide, and focus said audio pressure waves to propagate in said second direction ; and in that the contour of the non-flat reflector surface is adapted to compensate for the non-flat surface of the membrane by substantially equalizing distances of propagation for mutually different rays of acoustic signals propagating in said second direction such that a phase deviation, between said mutually different rays of acoustic signals, caused by said non-flat surface is substantially eliminated at an arbitrary distance (D3) from the audio generator . a first transducer element comprising a membrane having a surface which is non-flat; and means for causing the membrane to move in dependence on an input signal so as to cause audio waves to propagate in a first direction (M, 300, 300A, 300B) away from said membrane; and wherein a membrane having a surface which is non-flat; and means for causing the membrane to move in dependence on an input signal so as to cause audio waves to propagate in a first direction (M, 300, 300A, 300B) away from said membrane; and wherein the membrane has an outer perimeter which is flexibly attached to a portion of a transducer element body ; said outer perimeter defining a first aperture having a first aperture plane ; and wherein, in operation, the membrane is adapted to cause said audio pressure waves to propagate in the first direction (M, 300, 300A,) orthogonal to said first aperture plane ; wherein a second aperture , a reflector and directive guiding walls ; the reflector having a surface adapted to reflect acoustic signals in a second direction orthogonal to a plane of said second aperture ; said second direction being different from said first direction; wherein the acoustically reflective surface has a non-flat contour , characterized in that the reflector co-operates with the directive guiding walls so as to lead, guide, and focus said audio pressure waves to propagate in said second direction ; and in that the contour of the non-flat reflector surface is adapted to compensate for the non-flat surface of the membrane by substantially equalizing distances of propagation for mutually different rays of acoustic signals propagating in said second direction such that a phase deviation, between said mutually different rays of acoustic signals, caused by said non-flat surface is substantially eliminated at an arbitrary distance (D3) from the audio generator . <EOS>