Siegfried Linkwitz received the Diplom Ingenieur Electrical Engineering degree from Darmstadt Technical University, Germany,in 1961. He completed his Postgraduate studies at Stanford University, CA. He worked for 37 years in Research & Development for Hewlett-Packard, where he developed state-of-the-art electronic test equipment, such as microwave spectrum analyzers, network analyzers and EMI receivers. While at HP he participated for 18 years in national and international standards development for electromagnetic compatibility test instrumentation through ANSI and IEC/CISPR. In 1974 he developed the Linkwitz-Riley crossover filter out of a shared audio hobby with Russ Riley. Mr. Linkwitz retired from HP in 1998 and continued to pursue his life-long interests in audio and particularly in loudspeaker design. Between 1994 and 1999 he designed a line of dipole loudspeakers with moving coil drive units for Audio Artistry. In 1999 he set up LINKWITZ LAB website to educate on loudspeaker design and sound reproduction issues. Detailed information is provided to build electronics and loudspeakers according to the best practices learned in 45 years. His goal is “true to the original” stereo sound reproduction in normal living spaces. From his perspective, loudspeakers and rooms are now understood and done; microphones were done some time ago, but optimal stereo recording techniques are still to be demonstrated. (www.linkwitzlab.com).
The problems with stereo sound reproduction start already at the recording end of the signal chain. The sound transmission from the live event to its reproduction in a small room must be treated...