Rescued SDA SRS 2s

I recently picked up a pair of SDA SRS 2s from the curb on trash day not knowing anything about them other than the brand. I tested them this evening with my Technics SA-210. The right one sounded fine, but the left was all lows and no high end. I do not have the interconnect cable and wondered if that was the issue or if it’s something else. Any advice would be welcome.