| Andrew Cooke | Contents | Latest | RSS | Twitter | Previous | Next

C[omp]ute

Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Lepl parser for Python.

Colorless Green.

Photography around Santiago.

SVG experiment.

Professional Portfolio

Calibration of seismometers.

Data access via web services.

Cache rewrite.

Extending OpenSSH.

Last 100 entries

The Quest for Randomness; Chat Wars; Real-life Financial Co Without ACID Database...; Flexible Muscle-Based Locomotion for Bipedal Creatures; SQL Performance Explained; The Little Manual of API Design; Multiple Word Sizes; CRC - Next Steps; FizzBuzz; Update on CRCs; Decent Links / Discussion Community; Automated Reasoning About LLVM Optimizations and Undefined Behavior; A Painless Guide To CRC Error Detection Algorithms; Tests in Julia; Dave Eggers: what's so funny about peace, love and Starship?; Cello - High Level C Programming; autoreconf needs tar; Will Self Goes To Heathrow; Top 5 BioInformatics Papers; Vasovagal Response; Good Food in Vina; Chilean Drug Criminals Use Subsitution Cipher; Adrenaline; Stiglitz on the Impact of Technology; Why Not; How I Am 5; Lenovo X240 OpenSuse 13.1; NSA and GCHQ - Psychological Trolls; Finite Fields in Julia (Defining Your Own Number Type); Julian Assange; Starting Qemu on OpenSuse; Noisy GAs/TMs; Venezuela; Reinstalling GRUB with EFI; Instructions For Disabling KDE Indexing; Evolving Speakers; Changing Salt Size in Simple Crypt 3.0.0; Logarithmic Map (Moved); More Info; Words Found in Voynich Manuscript; An Inventory Of 3D Space-Filling Curves; Foxes Using Magnetic Fields To Hunt; 5 Rounds RC5 No Rotation; JP Morgan and Madoff; Ori - Secure, Distributed File System; Physical Unclonable Functions (PUFs); Prejudice on Reddit; Recursion OK; Optimizing Julia Code; Cash Handouts in Brazil; Couple Nice Music Videos; It Also Works!; Adaptive Plaintext; It Works!; RC5 Without Rotation (2); 8 Years...; Attack Against Encrypted Linux Disks; Pushing Back On NSA At IETF; Summary of Experimental Ethics; Very Good Talk On Security, Snowden; Locusts are Grasshoppers!; Vagrant (OpenSuse and IDEs); Interesting Take On Mandela's Context; Haskell Cabal O(n^2) / O(n) Fix; How I Am 4; Chilean Charity Supporting Women; Doing SSH right; Festival of Urban Intervention; Neat Idea - Wormholes Provide Entanglement; And a Link....; Simple Encryption for Python 2.7; OpenSuse 13.1 Is Better!; Little Gain...; More Details on Technofull Damage; Palmrest Cracked Too....; Tecnofull (Lenovo Support) Is Fucking Useless; The Neuroscientist Who Discovered He Was a Psychopath; Interpolating Polynomials; Bottlehead Crack as Pre-amp; Ooops K702!; Bottlehead Crack, AKG K701; Breaking RC5 Without Rotation; Great post thank you; Big Balls of Mud; Phabricator - Tools for working together; Amazing Julia RC5 Code Parameterized By Word Size; Chi-Square Can Be Two-Sided; Why Do Brits Accept Surveillance?; Statistics Done Wrong; Mesas Trape from Bravo; European Report on Crypto Primitives and Protocols; Interesting Omissions; Oryx And Crake (Margaret Atwood); Music and Theory; My Arduino Programs; Elliptic Curve Crypto; Re: Licensing Interpreted Code; Licensing Interpreted Code; ASUS 1015E-DS03 OpenSuse 12.3 SSD; translating lettuce feature files into stub steps files; Re: translating lettuce feature files into stub steps files

© 2006-2013 Andrew Cooke (site) / post authors (content).

NXT (Distributed Mode) Speakers

From: "andrew cooke" <andrew@...>

Date: Mon, 19 Jun 2006 18:29:28 -0400 (CLT)

Just noticed these.  http://www.elac.com/en/products/imago/dml.html has a
description and images.

My first reaction was - that must sound terrible!  How can you get good
stereo imaging if the phase information at high frequencies is lost?  For
years people have been trying to build extremely rigid speaker cones to
avoid the kind of behaviour that is a "feature" here; the only advantage
seems to be wide dispersion.

But then I thought - maybe there's something really cool happening here. 
Some kind of mix between chaotic motion and synthetic apertures.  It
seemed crazy, but then some highish-end audio companies seemed to be using
the technology.  So I poked around some more.

The technologoy is patented (how can you patent a bad speaker?) by NXT -
http://www.nxtsound.com/index.php?id=476&no_cache=1

It was difficult to find neutral opinions.  Since the technology enables
thin flat and curved panels it is very "marketable".   It's difficult to
separate marketng blurb from "this really sounds good".

Eventually I found this review -
http://www.findarticles.com/p/articles/mi_zdext/is_200308/ai_ziff46255/print
- for computer speakers.  You wouldn't expect that to be a very demanding
application, but the review was surprisingly negative.

Next, a HIFI Choice review of Mission speakers.  Two reviews, in fact. 
Their site is dead, but Google has caches if you click through the first
two hits for http://www.google.cl/search?q=hifi.choice+mission+NXT  Both
reviews are negative.

Finally, here's a detailed argument on ribbon speakers -
http://www.svconline.com/mag/avinstall_turning_pro/index.html - which
says:

Electrostatics and planar magnetics (ribbons) are driven uniformly over
their entire diaphragms. This is the exact opposite to the distributed
mode ideal of flat NXT panels, which operate in random phase across their
surface. Cones, on the other hand, are uniform (pistonlike) up to the
midrange. It is generally conceded that ribbons and electrostatic panels
tend to sound better than cones, while the distributed mode panels sound
worse. However, in certain pro applications in which a uniform phase line
array's excellent pattern control is not needed, the nature of NXT panel
radiation (the “antiribbon”) is an advantage. The wide coverage and random
phase of a well-executed NXT design, such as the Armstrong i-Ceilings
panel, is an advantage in the struggle to achieve wide uniform coverage
with low ceilings as well as high acoustic levels before feedback. The
random phase nature of the panel helps prevent feedback, effectively
randomizing the phase of the signal. The Armstrong panels actually sound
quite decent, to boot.

So, no cool chaotic synthetic aperture...

Andrew

Comment on this post