An estate sale find. No scratches or dings, grills are intact. Front speakers come with wall mounting brackets. I tested all three at 6-Ohms with an Onkyo amp. They sound amazing, the fronts appear to be fully functional. The center chanel sound had some scratchiness in the left woofer. I disasembeled it and found metal fragments in the magnet where the cone moves in and out. I cleared it out with compressed air and re-assembeled. It sound better bit still not as good as the right woofer. Both woofers tested fine with a multimeter. You can examine them when picking up. This is the info I found on the web. Acoustic Research 8.3 Phantom Speakers. Principle 3-way speaker with Placement Compensation Network. Frequency response 45 – 20.000 Hz. Recommended Amplifier Output 50 – 250 Watts. SPL (1w/1m) 89 dB. Dimensions (WxHxD) without stand 11,7″ x 28,5″ x 3,7. Cabinet Surface streamlined cabinet in versatile satin-finish aluminium with neoprene damping. Features Low profile enclosure. 1 plasma-hardened titanium dome tweeter. MagAlloyT 2 dome midrange. IllusionT 8 long-throw Carbon Series woofer. Dual binding posts for bi-wire/bi-amp. Acoustic Research Phantom 252c Center Speaker. Crossover Channel Qty: 2-way. Frequency Response: 70 – 20000 Hz. Recommended Amplifier Power: 50 Watt. Recommended Placing: on-wall mounted. Driver Type: mid/woofer driver, tweeter driver. Driver Qty: 1, 2. Driver Diameter: 1 m, 5.25 m. Driver Diameter (metric): 133 mm, 25 mm. Width: 55.88 cm. Depth: 8.38 cm. Height: 22.86 cm. Weight: 3.60 cm.