letters commenting on articles in Vol3-2

Vol 3-2 I received several letters commenting on articles in Volume 3, notably to the articles by Samuel Groner (low noise lab-grade measurement amp), Steven van Raalte (correcting transducer response with inverse filter) and Robert Munnig Schmidt (mechatronics approach to subwoofer design). These comments (some extend to several exchanges) can be downloaded here. The comments were in some cases accompanied by the following LTspice files, referenced in the text: jm-1.txt; jm-2.txt; rms-1.txt; rms-2.txt and finally jm-3.pdf (in French). Be sure to rename the .txt to .asc.