Koss S904 Powered Subwoofer Active Sub Home Audio HiFi Bass Speaker

Optimus Prime's Stereo Equipment Old School Audio - Old School Prices - Professionally Tested Product Description This Koss S904 powered subwoofer has been bench tested and confirmed fully working. The built-in amplifier powers up, the standby circuit functions, and the volume control operates correctly with no issues. Cosmetically the unit is in good used condition — the front baffle and enclosure show typical light wear from use, and the rear particle board cabinet edges show some chipping and wear consistent with age. Please review all photos for details. Highlights At A Glance ✔ Fully tested and verified ✔ Good cosmetic condition with minor wear and edge chipping on rear cabinet ✔ Fast, insured shipping, carefully packaged Testing & Verification The internal amplifier was powered up and verified working through the full volume range. The subwoofer driver was confirmed producing clean bass output with no distortion, rattles, or anomalies at listening levels. The standby circuit, volume control, subwoofer input, and phase switch on the rear panel were all exercised and confirmed functional. Shipping Fast, insured shipping from Minnesota. Item is carefully packaged for safe delivery.