| PAPERS | |
| Modulation and System Techniques in PWM and SDM Switching Amplifiers (PDF-1.6MB) | |
| Malcolm Hawksford | 107 |
| Switching amplifiers that use either sigma-delta modulation (SDM) or pulse-width modulation (PWM) can be modeled in terms of linear angle modulation. Distortion generated when applying feedback to PWM is demonstrated, and strategies to improve linearity are then presented. Also, a look-ahead SDM incorporating an energy-balancing binary decision threshold is examined. A unified analytic approach shows that SDM can compete in terms of linearity with PWM power amplifiers and that energy-balancing SDM can achieve similar peak signals. | |
| A Search for Best Error Metrics to Predict Discrimination of Original and Spectrally Altered Musical Instrument Sounds (PDF-461KB) | |
| Andrew B. Horner, James W. Beauchamp, and Richard H. Y. So | 140 |
| Knowing the required accuracy of harmonic components in decoded or synthesized periodic audio signals allows a designer to select an optimum strategy. An error metric of spectral accuracy was proposed and evaluated in subjective listening tests. Listeners were asked to discriminate sounds with randomly altered changes in spectral amplitude without any changes in the average spectrum or overall loudness. These tests confirmed the validity of the model. | |
| Advanced Simulation of a Condenser Microphone Capsule (PDF-394KB) | |
| Roger S. Grinnip III | 157 |
| An advanced model of a pressure condenser microphone capsule was used to simulate the performance of an experimental prototype. The external acoustic domain was modeled using the boundary-element method, which allowed the capsule to have an arbitrary shape. The results show excellent agreement throughout the measured frequency range. This coupled model was better than the conventional lumped-element techniques. | |
| Bit-Rate Scalable Intraframe Sinusoidal Audio Coding Based on Rate-Distortion Optimization (PDF-714KB) | |
| Richard Heusdens, Jesper Jensen, W. Bastiaan Kleijn, Valery Kot, Omar A. Niamut, Steven van der Par, Nicolle H. van Schijndel, and Renat Vafin | 167 |
| A parametric coder based on rate-distortion optimal sinusoid + noise coding of audio and speech signals is presented. The coder minimizes a perceptual distortion measure subject to a bit-rate constraint. A variable-length signal analysis is used to avoid preechoes and to reduce the intersegment correlation. Frequency differential coding is performed to exploit intrasegment correlations. In subjective listening tests using music and speech, this method often performed better than state-of-the-art MPEG-4 audio coders. | |
| STANDARDS AND INFORMATION DOCUMENTS | |
| AES Standards Committee News (PDF-94KB) | 189 |
| ATM networking; digitally-interfaced microphones; microphone specifications; Standards meetings | |
| FEATURES | |
| 12th Tokyo Regional Convention Report (PDF-270KB) | 190 |
| Exhibitors (PDF-149KB) | 194 |
| Program (PDF-593KB) | 196 |
| 120th Convention Preview, Paris (PDF-269KB) | 208 |
| Exhibit Previews (PDF-476KB) | 210 |
| Stereophonic Recording Techniques: Old Challenges, New Approaches (PDF-311KB) | 225 |
| 29th Conference, Seoul, Call for Papers (PDF-74KB) | 247 |
| 121st Convention, San Francisco, Call for Papers (PDF-74KB) | 248 |
| DEPARTMENTS | |
| News of the Sections (PDF-223KB) | 230 |
| Upcoming Meetings (PDF-229KB) | 233 |
| Sound Track (PDF-238KB) | 234 |
| Available Literature (PDF-184KB) | 236 |
| Membership Information (PDF-157KB) | 238 |
| Advertiser Internet Directory (PDF-163KB) | 239 |
| In Memoriam (PDF-161KB) | 245 |
| Sections Contacts Directory (PDF-151KB) | 249 |
| AES Conventions and Conferences (PDF-228KB) | 256 |
| EXTRAS | |
| Cover & Sustaining Members List (PDF-144KB) | |
| AES Officers, Committees, Offices & Journal Staff (PDF-186KB) | |
