※Shipping service. When I check the audio system with that in mind, many basic mistakes and unfinished tunings come up. In this separate issue, we have collected a lot of tuning know-how. Special Feature 1 = Audio System Tuning Law 300 Examples/Special Feature 2 = Sound Quality Improvement and Sound Insulation Techniques for Listening A Rooms/Special Feature 3 = Audio Component Sound Quality Improvement Technics/S59.11.20 Newly Released. Since the photograph is a sample, the actual item may be broken or there may be markings etc.