Description

Production techniques and careful design of components in recording and playback systems can help provide clarity, transparency, and perceptual staging to enhance listener involvement and artist connection from a recording and its reproduction. A brief overview begins with design and performance issues of halls, microphones, electronics, processes and loudspeakers. Tests that fit behavioral features for each of these components are described and perceptual hearing models are introduced to help interpret results. We examine tone clusters, sample synchronous peak error and masking issues. Audio examples of sonic illusions, suggestibility and waveform perception will help introduce discussions about the resolution experience, sonic art and production practice. Topics presented in a multi-channel perspective include how instruments, halls, and visual cues create a live concert experience and how microphone choices, placements and mix-in strategies constrict or expand a soundscape. These include time corrected stereo accenting, eigensonic reduction from loudspeakers, and supplemental driving of the recording and reproduction spaces. Methods to reduce loudspeaker presence and front biased imaging will be described. Demonstrations of microphone techniques, loudspeaker correction, and high-resolution files follow.

About the Speaker

Keith Johnson is known for his recordings and contributions to entertainment technology. Often known as “The Professor” his interests spanning music, technology and recording were recognized early when Ampex Corp awarded him a scholarship and training program for his high school three-channel recorder and microphone project. While at Stanford University, he recorded music groups and created a solid state portable three-channel recorder, which he would use for over 100 record releases. Sherman Fairchild learned of Johnson’s photolithography methods to create RF bias heads for the machine and licensed the “focused gap” technology for mastering recorders used by RCA. Johnson partnered Gauss Electrophysics to combine his recorder knowledge and air supported tape technology to standardize and dominate the high-speed cassette duplication industry for many years. Important contributions to the MCA Video Disk and related optical memory field as well as to loudspeakers were made at that time. Orchestral recordings for the Armed Forces Radio allowed Johnson to develop, test and improve his high-resolution electronics, microphones and active speakers. Examples of early work appeared on the Klavier label. During that time, he conceived an optical scanner to remove noise from damaged motion picture sound tracks. The device combines optical, video, sampling, and filter process technologies and has been used to restore important films. While mentoring and working with the rock band Ambrosia, he collaborated with Allan Parsons to make an expressive polyphonic sampler, the “Projectron”. Tracks appeared on important recordings to pioneer a major industry that would ultimately create realistic instrument sounds from a keyboard. Later Johnson collaborated with East West to introduce fully dimensional sampling to the keyboard industry. He helped partner Reference Recordings to help create a catalog of recordings that have set standards for their craftsmanship and sonic performance. Ongoing technology from this work has been applied to high-end products from Spectral and Avalon. To improve the “compact disk” he partnered with Pacific Microsonics and contributed important parts of the HDCD process. His knowledge to create unparalled conversion accuracy along with improved electronics from his recording work helped introduce precision high resolution encoding to the industry. When Microsoft Corp. bought the company, Johnson provided a speaker correction method to remove object sounds or colorations from inexpensive speakers. Its simplicity and small files have been incorporated in released software. Many awards include 2 Grammy winning releases, 7 nominations for Best Engineered Classical Recording, 2 Naird Indy winners for Best Recording, 2 Absolute Sound Golden Ear awards and 3 awards from Academy Advancing High Performance Audio. Recent interests include downloadable multi-channel sound and systems that automatically set up and operate without cables. He is also investigating hearing physiology and correction. He plays keyboard instruments and is a competitive runner.

Address

DeAnza 3 Auditorium
Apple R&D Campus
10500 N DeAnza Blvd, Cupertino, CA, USA

Directions

Finding De Anza 3 Auditorium

- De Anza 3 Auditorium is on the BACK side of the ground floor of Apple's De Anza 3 Building. De Anza 3 is a slightly older building located on the opposite side of Marianni Avenue from Infinity One and the Apple Campus Complex. (It is on the opposite side of the street if you are standing on the grass between Buildings 1 & 2.)

If you are arriving from 280, you have turned South on De Anza and are driving parallel to the Apple Campus, (Buildings 1-6), you will turn Left onto Marianni Avenue. Instead of turning into Apple Campus (Infinity Loop) on the left, instead turn right into the first driveway on the right, and drive to the back of the building around the right end, parking in the back parking lot. A set of double glass doors at the back of the building is the correct access - you will enter the glass doors and then go immediately right through the doors into the auditorium.