2004 May, Volume 52 Number 5

CONTENT

PAPERS

Analysis of Loudspeaker Line Arrays
Mark S. Ureda   467
A set of mathematical expressions is provided to estimate the performance of loudspeaker line arrays. These include expressions for the polar response, on-axis and off-axis pressure responses, and two-dimensional pressure fields of straight-line, curved, J, and progressive line arrays. In addition, expressions are provided to analyze the effects of curved radiating sources and gaps between sources in line arrays. Several examples are provided to compare estimated performance against measured data.

Fast Convolution Technique Using a Nonuniform Sampling Scheme: Algorithm and Applications in Audio Signal Processing
Mingsian R. Bai and Pingshun Zeung   496
Using a nonuniform sampling, a fast convolution algorithm greatly reduces the complexity and increases the computational efficiency by providing high resolution at low frequencies and low resolution at high frequencies. Examples of a head-related transfer function and a reverberant room response illustrate good subjective performance even though the results are distinguishable from direct convolution. This approach exploits the differences in spectral resolution for human hearing.

ENGINEERING REPORTS

Measurement of Reverberation Times Using a Wavelet Filter Bank and Application to a Passenger Car
Sang-Kwon Lee   506
Measuring the reverberation time in small spaces using traditional methods is difficult because the product of the bandwidth and reverberation time is too small. A wavelet transform method using a wavelet filter bank has been successfully used to measure the reverberation time of the passenger compartment of an automobile, where such times were on the order of 0.05 seconds. Synthetic impulse responses from a toy balloon were used as an impulse response for exciting the space.

Wavetable Matching of Pitched Inharmonic Instrument Tones
Clifford So and Andrew B. Horner   516
By relaxing the normal assumption of harmonic tones in wavetable synthesis, a new approach allows for using wavetables for plucked instruments, such as the Chinese qin and yangqin. The new method uses a hierarchical grouping of the original tone's partials based on their normalized frequency deviation. Using a fully automatic operation, the results show slight improvement on the perceived match with harmonic tones and a greatly improved match on pitched inharmonic tones.

LETTERS TO THE EDITOR

Dipole, Monopole, or Near-Field Woofer-Physics and Perception
Tomas Salava   530

Author's Reply
Siefried Linkwitz   532

Comments on "Why Is Bass Reproduction from a Dipole Woofer in a Living Room Often Subjectively More Accurate Than from a Monopole Woofer?"
Frank Fahy   532

STANDARDS AND INFORMATION DOCUMENTS

AES Standards Committee News   533
Standards in Action: AES47 professional audio networking

FEATURES

Wavefield Synthesis: Evolution from Stereophony and Some Practical Challenges   538

117th Convention, San Francisco, Call for Workshop Participants   569

DEPARTMENTS

Review of Acoustical Patents   535
News of the Sections   544
Sound Track   550
New Products and Developments   552
Upcoming Meetings   554
Available Literature   554
Membership Information   556
Advertiser Internet Directory   557
In Memoriam   567
Sections Contacts Directory   570
AES Conventions and Conferences   576

FPO For the cover:

2004 May, Volume 52 Number 5

spine: 2004 May, Volume 52 Number 5