Hey, so I can't seem to fill the space between the split and the speaker arm. Originally my plane was to loft the space between them and then use the indent tool. However, whatever I do it always says that the loft would result in zero-thickness geometry. I've tried using fit spline, faces, edges, offsetting entities but I can't get it to work. If anyone could help me I'd be grateful.

Edit: Don't know if this is helpful, but I managed to fill in the space by using a surface loft and a boss base and cutting out the uneven parts. However I still can't combine that with the rest of the ear cup.