Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



TECH SPACE
New sound diffuser is 10 times thinner than existing designs
by Staff Writers
Raleigh NC (SPX) Jun 08, 2017


A conventional, two-dimensional conventional Schroeder diffuser (on the left), compared to a new, 'ultra-thin' two-dimensional Schroeder diffuser (at right). The ultra-thin diffuser is 10 times thinner. Image courtesy Yun Jing.

Researchers from North Carolina State University and Nanjing University have developed an "ultra-thin" sound diffuser that is 10 times thinner than the widely used diffusers found in recording studios, concert venues and movie theaters to reduce echoes and improve the quality of sound. The new design uses less material, which would reduce cost, as well as taking up far less space.

In a typical room with flat walls, sound waves usually bounce off the walls, like light reflecting off a mirror. This creates echoes and overlapping sound waves that result in uneven sound quality depending on where you are in the room.

"Sound diffusers are panels placed on the walls and ceiling of a room to scatter sound waves in many different directions, eliminating echoes and undesirable sound reflections - ultimately improving the quality of the sound," says Yun Jing, an assistant professor of mechanical and aerospace engineering at NC State and corresponding author of a paper on the work.

But the most widely used diffusers, called Schroeder diffusers, can be very bulky. That's because the size of a diffuser is governed by the wavelength of the sound it needs to diffuse. Specifically, the depth of a Schroeder diffuser is about half of the wavelength of the lowest sound it needs to diffuse.

For example, a typical man's voice can be as low as 85 hertz, with a wavelength of 4 meters or 13.1 feet. If that's the lowest sound the Schroeder diffuser will have to deal with, the diffuser would need to be roughly 2 meters - or just over 6.5 feet - thick.

But the new, ultra-thin diffuser design requires a thickness that is only 5 percent of the sound's wavelength. So, instead of being 2 meters thick, it would only be 20 centimeters - or less than 8 inches - thick.

"Diffusers are often made out of wood, so our design would use 10 times less wood than the Schroeder diffuser design," Jing says. "That would result in lighter, less expensive diffusers that allow people to make better use of their space."

This reduction in diffuser thickness is made possible by the design of the individual cells in the diffuser.

A Schroeder diffuser looks like a panel of evenly spaced squares, which are identical in length and width, but vary in depth.

The ultra-thin diffuser also consists of evenly spaced squares, but the squares appear to be of different sizes. That's because each of the squares is actually an aperture that opens into a thin, underlying chamber. These chambers all have identical dimensions, but the size of the apertures varies significantly - accomplishing the same sound diffusion as the much larger Schroeder diffusers.

"We've built fully functional prototypes using a 3-D printer, and it works," Jing says. "The design should work just as well using wood."

The paper, "Ultra-thin Acoustic Metasurface-Based Schroeder Diffuser," is published in the American Physical Society journal Physical Review X. Lead authors of the study are Yifan Zhu and Xudong Fan of Nanjing University. The paper was co-authored by Bin Liang and Jianchun Cheng of Nanjing University.

TECH SPACE
New scaling law predicts how wheels drive over sand
Boston MA (SPX) May 31, 2017
When engineers design a new aircraft, they carry out much of the initial testing not on full-sized jets but on model planes that have been scaled down to fit inside a wind tunnel. In this more manageable setting, they can study the flow of air around an aircraft under all manner of experimental conditions. Scientists can then apply scaling laws - mathematical relationships of proportionali ... read more

Related Links
North Carolina State University
Space Technology News - Applications and Research


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TECH SPACE
First Year of BEAM Demo Offers Valuable Data on Expandable Habitats

Conch shells may inspire better helmets, body armor

NASA honors Kennedy's space vision on 100th birthday

MIT researchers engineer shape-shifting food

TECH SPACE
Colossal rocket-launching plane rolls toward testing

Dream Chaser Spacecraft Passes Major Milestone

NASA's Space Launch System Engine Testing Heats Up

Successful launch puts New Zealand in space race

TECH SPACE
Curiosity Peels Back Layers on Ancient Martian Lake

Student-Made Mars Rover Concepts Lift Off

Illinois Company Among Hundreds Supporting NASA Mission to Mars

Halos discovered on Mars widen time frame for potential life

TECH SPACE
California Woman Charged for Trying to Hand Over Sensitive Space Tech to China

A cabin on the moon? China hones the lunar lifestyle

China tests 'Lunar Palace' as it eyes moon mission

China to conduct several manned space flights around 2020

TECH SPACE
Propose a course idea for the CU space minor

Leading Global Air And Space Law Group Joins Reed Smith

New Horizons for Alexander Gerst

Government space program spending reaches 62B dollars in 2016

TECH SPACE
Bamboo inspires optimal design for lightness and toughness

Model for 2-D materials based RRAM found

New scaling law predicts how wheels drive over sand

Space junk could destroy satellites, hurt economies

TECH SPACE
Giant Ringed Planet Likely Cause of Mysterious Eclipses

Viable Spores, DNA Fragments Discovery at ISS Justifies Biosphere's Expansion

Russia thinks microorganisms may be living outside the space station

The race to trace TRAPPIST-1h

TECH SPACE
A whole new Jupiter with first science results from Juno

First results from Juno show cyclones and massive magnetism

Jupiters complex transient auroras

NASA's Juno probe forces 'rethink' on Jupiter




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement