An electronic device may be provided with peripheral conductive housing structures having a segment that forms a resonating element for an antenna. A speaker may be mounted to a mid-chassis of the electronic device. A printed circuit may be mounted to the speaker and may have a ground trace for the antenna. A conductive spring may extend through the printed circuit and the speaker to couple the ground trace to the mid-chassis. A conductive contact pad may be welded to an aluminum layer such as an aluminum layer used to form the mid-chassis. A conductive spring such as the conductive spring coupled to the ground traces may press against the contact pad. The contact pad may include gold or nickel-plated stainless steel. The contact pad may provide a strong electrical connection between the conductive spring and the aluminum layer.