Download Entire Journal (15.1MB)
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| Volume 56 Number 12 | 2008 December |
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CONTENTS Download Entire Journal (15.1MB) |
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| Editor’s Note, 2008 Reviewers (PDF-73KB) John Vanderkooy | 1035 |
| PAPERS | |
| Efficient Algorithms and Structures for Fractional Delay Filtering Based on Lagrange Interpolation (PDF-675KB) (HI-RES PDF-7.6MB) | |
| Andreas Franck | 1036 |
| Fractional delay filters, which allow for delays that are not aligned at samples values, are important in many signal processing algorithms. Lagrange interpolation is frequently used for this purpose in situations where delay values change frequently, because filter coefficients can be calculated from explicit formulas. The large number of algorithms for Lagrange interpolation necessitates an analysis of their computational effort. A novel structure that is efficient, scalable, and well suited for parallel hardware or software implementation is described. | |
| Hierarchical Bandwidth Limitations of Surround Sound—Part I: Psychoacoustically Hierarchical Transform (PDF-379KB) (HI-RES PDF-4.3MB) | |
| Yu Jiao, Sławomir Zieli´nski, and Francis Rumsey | 1057 |
| In order to reduce the increase data rate of multichannel surround sound, a hierarchical bandwidth limiting technique is proposed. In this approach, the original signals are transformed into a hierarchical representation, which is then band-limited and re-transformed back into the original representation. Subjective listening tests were used to evaluate two such approaches: Gerzon MSBTF and Karhumen–Lòeve transforms. The results showed that the signal-dependent hierarchical encoding performed better than the signal-independent techniques, but both techniques were better than conventional methods. | |
| Parallel Look-Ahead Digital SDM with Energy-Balance Binary Comparator (PDF-1.0MB) (HI-RES PDF-14.5MB) | |
| Malcolm Omar Hawksford | 1069 |
| Because conventional sigma–delta modulators have a proclivity toward instability when excited by high-amplitude audio signals, a modified detection process incorporates an energy metric. This new paradigm uses the sums of the energy in the filter integrators as part of the five-sample look-ahead. Unlike a conventional sigma–delta modulator, which only considers the filter output, this approach also lowers the stored energy within the filter. As an intrinsic tradeoff, increased stability at high levels increases noise modulation. An energy-balance algorithm can use a highly parallel matrix operation for computational efficiency. | |
| ENGINEERING REPORTS | |
| All-Pass Linear Arrays (PDF-445KB) (HI-RES PDF-5.5MB) | |
| Michael M. Goodwin | 1090 |
| When using multiple drivers in a linear array structure to achieve an increased soundfield level, the designer must consider the spatially dependent frequency response of the array. By using specifically designed weights for the array elements, the array can be made to have a spatial all-pass characteristic such that there is minimal variation in the frequency response of the array with respect to angle. Weights that achieve this property correspond to FIR filter approximations of all-pass filters. A search algorithm for such approximations is described, and examples are provided to demonstrate the design freedoms of the proposed approach, including the use of crossover-filter configurations. | |
| CORRECTIONS | |
| Correction to “Nonlinear Distortion Synthesis Using the Split-Sideband Method, with Applications to Adaptive Signal Processing” | |
| V. Lazzarini, J. Timoney, and T. Lysaght (PDF-45KB) | 1102 |
| STANDARDS AND INFORMATION DOCUMENTS | |
| AES Standards Committee News (PDF-181KB) | 1104 |
| Preferred sampling frequencies; serial transmission format; flutter measurement; serial multichannel interface; extended file format for audio; ATM networks; analog recording; transfer technologies; grounding & EMC | |
| FEATURES | |
| 125th Convention Report, San Francisco (PDF-3.3MB) | 1106 |
| Exhibitors (PDF-1.1MB) | 1120 |
| Are You Hearing What I’m Hearing? (PDF-984KB) Francis Rumsey | 1126 |
| How FCC “White Space” Decision Will Affect U.S. Pro Audio (PDF-350KB) David Josephson | 1132 |
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| Education News (PDF-227KB) Jason Corey | 1136 |
| 127th Convention, New York, Call for Papers (PDF-33KB) | 1150 |
| Index to Volume 56 (PDF-219KB) | 1152 |
| DEPARTMENTS | |
| News of the Sections (PDF-183KB) | 1138 |
| Sound Track (PDF-75KB) | 1141 |
| Upcoming Meetings (PDF-43KB) | 1142 |
| New Products and Developments (PDF-43KB) | 1142 |
| Membership Information (PDF-181KB) | 1143 |
| Advertiser Internet Directory (PDF-105KB) | 1145 |
| In Memoriam (PDF-111KB) | 1149 |
| AES Annual Report (PDF-47KB) | 1151 |
| Sections Contacts Directory (PDF-153KB) | 1168 |
| AES Conventions and Conferences (PDF-115KB) | 1176 |
| EXTRAS | |
| Cover & Sustaining Members List (PDF-94KB) | |
| AES Officers, Committees, Offices & Journal Staff (PDF-83KB) | |
| Advertisements (PDF-1.6MB) | |
| 125th Convention Papers (Insert) (PDF-56KB) | |
| 125th Convention Audio Recordings (Insert) (PDF-1.1MB) | |