A high-density electrode catheter (101, 120, 120', 120", 120"', 300, 320, 320', 530, 600) comprising: a catheter shaft including a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis (a-a); a shaft magnetic position sensor disposed along a distal portion of the catheter shaft; a flexible tip portion (110, 122, 190, 190', 190", 190′′′, 302, 324, 380, 400) located adjacent to the distal end of the catheter shaft, wherein the flexible tip portion (110, 122, 190, 190', 190", 190′′′, 302, 324, 380, 400) includes a flexible framework comprising: first and second longitudinally extending outboard arms (103, 106, 126-1, 126-4, 312-1, 312-4, 322-1, 322-6, 402-1, 402-5, 404-1, 404-5, 422-1, 422-4, 428-1, 428-5, 440-1, 440-5, 452-1, 452-4, 462-1, 462-7, 532-1, 532-5); first and second longitudinally extending inboard arms (104, 126-2, 312-1, 322-3, 102-2, 404-2, 422-2, 428-2, 440-2, 452-3; 105, 126-3, 312-3, 322-4, 402-4, 404-4, 422-3, 428-4, 440-4, 452-5); and a central arm (126-5, 125-5, 192-5, 382-4, 402-3, 404-3, 428-3, 432, 440-3, 462-4, 532-3) that extends between the first and second longitudinally extending inboard arms; a plurality of electrodes disposed on the flexible framework; a proximal coupler (128, 328, 536, 606) from which the first and second outboard arms, the first and second inboard arms, and the central arm extend, wherein the first and second outboard arms and the first and second inboard arms exit the proximal coupler (128, 328, 536, 606) on a first plane; characterised in that the central arm exits the proximal coupler (128, 328, 536, 606) on either side of the first plane and extends distally away from the proximal coupler and toward the first plane; and a tip magnetic position sensor disposed on a distal portion of the flexible framework. a catheter shaft including a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis (a-a); a shaft magnetic position sensor disposed along a distal portion of the catheter shaft; first and second longitudinally extending outboard arms (103, 106, 126-1, 126-4, 312-1, 312-4, 322-1, 322-6, 402-1, 402-5, 404-1, 404-5, 422-1, 422-4, 428-1, 428-5, 440-1, 440-5, 452-1, 452-4, 462-1, 462-7, 532-1, 532-5); first and second longitudinally extending inboard arms (104, 126-2, 312-1, 322-3, 102-2, 404-2, 422-2, 428-2, 440-2, 452-3; 105, 126-3, 312-3, 322-4, 402-4, 404-4, 422-3, 428-4, 440-4, 452-5); and a central arm (126-5, 125-5, 192-5, 382-4, 402-3, 404-3, 428-3, 432, 440-3, 462-4, 532-3) that extends between the first and second longitudinally extending inboard arms; a plurality of electrodes disposed on the flexible framework; a proximal coupler (128, 328, 536, 606) from which the first and second outboard arms, the first and second inboard arms, and the central arm extend, wherein the first and second outboard arms and the first and second inboard arms exit the proximal coupler (128, 328, 536, 606) on a first plane; characterised in that the central arm exits the proximal coupler (128, 328, 536, 606) on either side of the first plane and extends distally away from the proximal coupler and toward the first plane; and a tip magnetic position sensor disposed on a distal portion of the flexible framework.