Is nowadays Digital Audio better than 80’s?

Prof David Herrin - Kentucky University measured dynamic range of vynil produced before 80’s, CD produced in 80’s and compare to CD produced after 00’s.

Interesting result that average dynamic range of CD produced in 80’s is 12-16 dB compare to CD produced after 00’s only 8 dB. It is paradox that dynamic range is lower while digital audio technology is much more advance.

Because of most people listening to music from handphone, CD producers have to compress audio signal to 8 dB so listener can listen to weak sound better and dont feel pain when the music level increase.

Architectural Acoustic Study on Chinese Opera

Chinese Opera has become a traditional art form since Yuan Dynasty (1271 - 1368) and became popular among common people. Chinese Opera is a comprehensive performing art that combines singing, music, dialogue, acrobatics, martial arts, and pantomime. It represents the culmination and distillation of two thousand years of Chinese civilization. Accompanied by traditional musical instruments, actors present unique melodies as well as dialogues which were beautifully written and of high literary value.

Peking Opera artist performed “The Drunken Concubine” (Photo VCG)

Chinese Opera Singing is accompanied by traditional Chinese acoustic music instruments: Erhu, Banhu, Yueqin, Sheng, Pipa, et cetera. Most of the musical played at Chinese Opera are string instruments with frequencies ranging from about 125 Hz to 4000 Hz.

Illustration of Chinese Acoustical Music Instrument accompany Chinese Opera Singing

Originally Chinese Opera Architectural Acoustic Features was Pavilion Stage above the audience. The caisson (dome shape ceiling) and backstage wall reflected and amplification acoustics sound to the audience area. The caisson is a wooden construction system that covers opera stages for rain protection and sound control. Caissons in China display a diverse range of geometric expressions, delicate manufacturing, structural behaviors, and acoustic qualities

This footage show how Dome Shape of Caisson amplified acoustics sound and summing with rear stage wall reflection sound to the audience

Architecture of Early Chinese Opera House is Amphitheatre Pavilion with caisson ceiling. The oldest amphitheater pavilion for Chinese Opera is Niuwang Temple, Shaanxi Province built in 1283 AD. Width: 7.45 m; Depth: 7.42 m; Height: 3.79 m

This footage shows the early design of the Caisson in the oldest amphitheater pavilion Niuwang Temple

The Changyin Pavilion, built from 1772 to 1776 during the reign of Emperor Qianlong, is the stage of a royal theater. The theater includes three structures: the stage at Changyin Pavilion, the auditorium in the Yueshi Building and the backstage is inside the Banxi Building, all located in Ningshou Palace - also known as the Qianlong Garden - which is in the northeast of the Forbidden City's inner court.

The isometric drawing of the Changyin Pavilion shows the 7 areas of the Building Architecture

Such equipment enables the artists to present a variety of dramatic effects. Performers and settings could “emerge from beneath the floor” or “descend from the heaven,” with the well allowing the actors to perform scenarios such as lotuses blooming from springing waters. 

File of artist performing traditional opera at Changyin Pavilion after reopen. (Photo China Daily)

Improving Transmission Loss of Sound Insulation Panels Using Periodic Viscoelastic Materials

Publication Information

Paper Title: Transmission Loss Improvement of Sound Insulation Panel with Viscoelastic Material in Periodic Configuration

Abstract:

The advantage periodic viscoelastic material configuration at single panel and sound insulation panel to improve low frequency transmission loss is observed in this paper. Thus, the predictive formula for transmission loss could be obtained. The sample plates were made of MDF 3 mm. There were three periodic configurations that have been tested: orthogonal, diagonal, and ribbed. Transmission loss was measured to each sample: single panel, single panel with periodic configuration of viscoelastic material, sound insulation panel with periodic configuration of viscoelastic material. All of the measurement data were compared to the theoretical calculation.

It was found that transmission loss improvement along 125 Hz – 250 Hz of single panel with periodic configuration of viscoelastic material was only around 7 dB – 16 dB; while sound insulation panel was gained transmission loss up to 14 dB – 20 dB. The transmission loss trend line of diagonal periodic configuration appeared as the highest among other configurations.

Empirical formula of transmission loss along 125 Hz – 1000 Hz can be described as R ≈ 10 (log f- 2)  x (0.6 ρs)  + 9 (dB) for single with periodic configuration of viscoelastic material and R ≈ 10 (log f- 2)  x (0.1 ρs)  + 19 (dB) for sound insulation panel with periodic configuration of viscoelastic material.

Presented at: Regional Conference on Acoustics and Vibration (RECAV) 2017

Conference Date: 26–29 November 2017

Location: Bali, Indonesia

Research Areas:

• Building Acoustics

• Sound Insulation

• Transmission Loss

• Viscoelastic Materials

• Structural Vibration Control

• Architectural Acoustics

• Noise Control Engineering

• Building Physics

• Acoustic Material Engineering

This publication reflects my ongoing commitment to applying scientific research and experimental testing to improve building performance. By combining material science, structural acoustics, and practical engineering, the research contributes to the development of more effective sound insulation systems that enhance occupant comfort and create quieter, healthier built environments.

RECAV 2017 – Regional Conference on Acoustics and Vibration, Bali, Indonesia

Noise control has become one of the most important aspects of modern building design, particularly in offices, hotels, residential buildings, healthcare facilities, and educational environments. While conventional sound insulation systems perform reasonably well at mid and high frequencies, achieving effective low-frequency sound insulation remains a significant engineering challenge because structural resonance allows vibration energy to pass through partitions more easily.

This research, presented at the Regional Conference on Acoustics and Vibration (RECAV) 2017 in Bali, Indonesia, investigates an innovative approach to improving the transmission loss of sound insulation panels by incorporating periodically arranged viscoelastic materials within the panel structure. The study builds upon the principle that viscoelastic materials dissipate vibration energy by converting mechanical energy into heat, thereby reducing the amount of sound transmitted through building partitions.

The research experimentally evaluated several periodic viscoelastic configurations—including orthogonal, diagonal, and ribbed patterns—using 3 mm MDF specimens tested as both single-layer panels and composite sound insulation panels. Laboratory measurements were conducted following recognized ASTM acoustic testing procedures, and the measured transmission loss was compared with theoretical predictions to evaluate the effectiveness of each configuration.

The results demonstrated that periodic viscoelastic configurations can substantially improve low-frequency acoustic insulation. For the 125–250 Hz frequency range, transmission loss increased by 7–16 dB for single panels incorporating viscoelastic material and by 14–20 dB for composite sound insulation panels. Among the tested configurations, the diagonal periodic arrangement delivered the most consistent performance and showed the strongest regression trend compared with the orthogonal and ribbed layouts. The study also developed empirical equations for predicting transmission loss between 125 Hz and 1000 Hz, providing a practical engineering reference for future acoustic panel design.

Beyond the numerical improvements, this research demonstrates how material engineering and structural configuration can work together to improve acoustic performance without relying solely on increasing wall thickness or mass. The findings contribute to the development of lighter, more efficient sound insulation systems that are applicable to high-performance buildings where occupant comfort, privacy, and environmental quality are critical design objectives.

Presenting this work at RECAV 2017 represents an important milestone in my research journey in building acoustics, noise control engineering, and building physics. The investigation strengthened my understanding of vibration damping, sound transmission mechanisms, and advanced acoustic material design—knowledge that continues to inform my consulting work at ALTA Integra in delivering evidence-based acoustic solutions for commercial, residential, institutional, and mixed-use developments.

Optimizing Small Room Acoustics Through Splayed Wall Design Using Finite Element Method

Publication Information

Paper Title: Study of the Effect of Splaying Wall to Modify Acoustic Modes Distribution in Small Room

Abstract:

Modes are known as one of the important acoustical issues in small rooms. These phenomena could drastically change the spectral and temporal characteristics of sound. Studies have been conducted on optimizing rectangular room dimensions, optimizing source and listener positions, and improving low-frequency performance using acoustic panels. However, achieving the best room ratio often requires significantly reducing the room dimensions.

This paper investigates the effect of splayed walls as an alternative approach to modifying room modes without sacrificing excessive usable space. Axial room modes from different room configurations—including random, splayed wall, Bolt, Louden, and Cox room ratios—were calculated and compared. The low-frequency characteristics of small rooms were analyzed using Finite Element Method (FEM) simulation, enabling sound pressure level (SPL) responses to be graphed and statistically evaluated.

The results show that introducing splayed walls into a room with random dimensions can redistribute room modes more evenly, producing a modal distribution comparable to the Cox room ratio, although with an increase in SPL standard deviation. Future work will investigate the perceptual significance of these findings through psychoacoustic evaluation.

Conference: Regional Conference on Acoustics and Vibration (RECAV) 2017

Date: 26–29 November 2017

Location: Bali, Indonesia

Research Topics:

• Architectural Acoustics

• Small Room Acoustics

• Room Modes

• Room Geometry Optimization

• Finite Element Method (FEM)

• Computational Acoustic Simulation

• Passive Acoustic Design

• Building Physics

This publication reflects my continuing commitment to applying scientific research and numerical analysis to solve real-world acoustic challenges, bridging academic investigation with practical engineering solutions for high-performance buildings.

---

RECAV 2017 – Regional Conference on Acoustics and Vibration, Bali, Indonesia

One of the most persistent challenges in small-room acoustics is the presence of room modes, or standing waves, which can create excessive bass peaks, deep nulls, and uneven frequency response. These modal resonances often color the sound, making accurate music reproduction, recording, and critical listening difficult.

In 2017, I presented this research at the Regional Conference on Acoustics and Vibration (RECAV 2017) in Bali, Indonesia. The study investigated an alternative architectural strategy for improving low-frequency performance without sacrificing valuable floor area.

Rather than relying solely on the traditional approach of resizing rooms to match recommended acoustic ratios such as Bolt, Louden, or Cox, this research explored whether splayed (non-parallel) walls could redistribute room modes while preserving more usable space.

To evaluate this concept, I developed numerical models using the Finite Element Method (FEM) to simulate the acoustic behavior of several room geometries. The research compared conventional rectangular rooms with optimized room ratios and a modified room incorporating splayed walls. The simulations analyzed modal distribution, sound pressure level (SPL), and standing-wave behavior across the low-frequency range.

The results showed that introducing splayed walls helped redistribute axial room modes more evenly and produced a more diffuse sound field while requiring significantly less reduction in room volume than redesigning the room to ideal proportions. Although some frequency peaks remained pronounced—indicating that additional treatments such as bass traps or optimized loudspeaker and listener placement would still be beneficial—the study demonstrated that room geometry itself can serve as an effective passive acoustic design strategy.

This research reinforced an important principle that continues to guide my consulting work today: excellent acoustics begin with architectural design rather than acoustic treatment alone. Decisions about room proportions, geometry, and building layout made during the earliest design stages can significantly influence the final acoustic performance of studios, home theaters, control rooms, meeting spaces, classrooms, and other critical listening environments.

Presenting this paper at RECAV 2017 marked an important milestone in my professional journey, strengthening my expertise in architectural acoustics, building physics, and computational acoustic simulation. It also laid the foundation for my ongoing approach at ALTA Integra, where evidence-based engineering, numerical modeling, and human-centered building performance are integrated to create spaces that sound as good as they look.

Overall Thermal Transfer Value (OTTV)

Overall Thermal Transfer Value (OTTV)

Adalah nilai rata-rata kalor panas yang masuk ke dalam bangunan melalui rambatan panas benda padat (konduksi) selubung bangunan dan rambatan panas melalui gelombang cahaya (radiasi).

Dalam perancangan facade, windows dan skylight pada bangunan tropis perlu diperhitungkan nilai OTTV agar ruangan tidak panas berlebihan atau meringankan beban pendinginan AC sehingga di dapatkan ruangan yg sejuk dan hemat energi.

#buildingphysic #buildingthermal #buildingthermalperformance #thermalcontrol #daylight #skylight #windows #thermalinsulation #greenbuilding #aircondition #architecture #architect #architectphotography #architecturetravel