One variation of a system for collecting biosignal data includes: a left junction； a right junction； a first band spanning the left and right junctions； a first band adjuster configured to adjust a length of the first band between the left and right junctions； a second band spanning the left and right junctions and radially offset from the first band about a lateral axis spanning the left and right junctions； a second band adjuster configured to adjust a length of the second band between the left and right junctions； a first electrode fixedly mounted to the first band and centered between the left and right junctions； a second electrode mounted to the first band offset from the first electrode and laterally-adjustable along the length of the first band； and a third electrode mounted to the second band and laterally-adjustable along the length of the second band.
