Building The World’s Best DML Speakers For Under $115

October 26, 2019 by Sharon Lin 35 Comments

Flat panel speakers are heavily reliant on the material they’re mounted on for the best acoustic quality. In particular, for DML (distributed mode loudspeaker) speakers, sound is produced through the distribution of vibration modes in the panel. You can easily spend far too much on special exciter foam or optimized materials for producing the best quality sound.

[Tech Ingredients] does a deep dive into how to build high-quality and low-cost DML speakers using some interesting materials, such as acoustic ceiling tiles and styrofoam. He analyzes their frequency based on the material and shape used and demonstrates how a full setup sounds with studio microphones and stereo speakers installed. The shapes can allow the resonances for different speakers to be translated so that they don’t overlap – peaks can be matched with troughs to produce a more even sound. Squares with rounded edges work the best for translating the resonance.

Balsa wood is mainly used for low frequencies and styrofoam for high frequencies, although the ceiling tiles work as well as either material and are significantly cheaper. Rather than retrofitting into drop ceiling metal frames, he instead installs his panels vertically. He shows the process for preparing the styrofoam and ceiling tiles for hanging, including tips for creating a makeshift circular saw for punching out holes and securing cotter pins with epoxy.

[Tech Ingredients] goes through experimenting with unusual shape and material combinations in order to produce the best possible speakers. It’s a fascinating video that walks through the ins and outs of DIYing your own set of speakers, and it’s worth a watch even just to hear about the acoustic properties of materials.

[Ed Note: Yes, this video is a bit long in the tooth, but we keep getting tips for it, so it’s news to someone! And it’s cool regardless. But feel free to skip on if you’ve seen this one before.]
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Arm Allows Custom Instructions

October 23, 2019 by Al Williams 31 Comments

We’re surrounded by ARM processors, which enjoy a commanding foothold in the consumer market, especially with portable electronics. However, Arm Holdings has never focused its business model on manufacturing chips, instead licensing its CPUs to others who make the physical devices. There is a bit of a tightrope to walk, though, because vendors want to differentiate themselves while Arm wants to keep products as similar as possible to allow for portability and reuse of things like libraries and toolchains. So it was a little surprising when Arm announced recently that for the first time, they would allow vendors to develop custom instructions. At least on the Armv8-M architecture.

We imagine designs like RISC-V are encroaching on Arm’s market share and this is a response to that. Although it is big news, it isn’t necessarily as big as you might think since Arm has allowed other means to do similar things via special coprocessor instructions and memory-mapped accelerators. If you are willing to put in some contact information, they have a full white paper available with a pretty sparse example. The example shows a population count function hand-optimized into 12 Arm instructions. Then it shows a single custom instruction that would do the same job. However, they don’t show the implementation nor do they offer any timing data about speed increases.

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The Arduino IDE Finally Grows Up

October 21, 2019 by Al Williams 105 Comments

While the Arduino has a very vocal fan club, there are always a few people less than thrilled with the ubiquitous ecosystem. While fans may just dismiss it as sour grapes, there are a few legitimate complaints you can fairly level at the stock setup. To address at least some of those concerns, Arduino is rolling out the Arduino Pro IDE and while it doesn’t completely address every shortcoming, it is worth a look and may grow to quiet down some of the other criticisms, given time.

For the record, we think the most meaningful critiques fall into three categories: 1) the primitive development environment, 2) the convoluted build system, and 3) the lack of debugging. Of course, there are third party answers for all of these problems, but now the Pro IDE at least answers the first one. As far as we can tell, the IDE hides the build process just like the original IDE. Debugging, though, will have to wait for a later build.

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Name A Hacker Camp

October 19, 2019 by Jenny List 31 Comments

Many of us look forward to visiting a summer hacker camp, as an opportunity to immerse ourselves in some of the coolest and most stimulating stuff that comes out of our community. The names trip off the tongue, ToorCamp, CCCamp, EMFcamp, BornHack, and more.

There’s one major event that doesn’t trip off the tongue in the same way though, because though it’s one of the oldest in our calendar it doesn’t have the same name every time. Since the end of the 1980s the Netherlands has seen a sequence of hacker camps with three letter names such as HAR, OHM, and SHA. Every four years these events delight and amaze us, and every four years they need a new name. Do you think you can help them pick one for 2021?

There are a few ground rules to observe, for the would-be coiner of a new moniker. The tradition is of a three-letter acronym, usually one with a meaning somewhere in technology, and so far always containing the letter H somewhere to stand for “Hack” in some form. The idea is that it should somehow encapsulate the spirit of hacker camp culture rather than simply be three words containing “Hack”. HAR for example was Hacking At Random, OHM was Observe Hack Make, and SHA was Still Hacking Anyway. So if you can dream up a TLA within those parameters, there is a group of hackers in the Netherlands who might like to hear from you. We suspect that HAD is already taken.

If you want to know more about the Netherlands camps, read our review of SHA, in 2017.

Header image: [Renze]. “Met Elkaar Hacken” means something close to “Hack together”.

This Week In Security: A Digital Café Américain, The Linux Bugs That Weren’t, The Great Nation, And More

October 18, 2019 by Jonathan Bennett 16 Comments

A government is going after a human rights activists in Morocco. It sounds familiar, but I don’t think Humphrey Bogart is running the gin joint this time around.

Questionable Casablanca references aside, Amnesty International has reported another attack against human rights workers. In this case, a pair of Moroccan activists were targeted with what appears to be NSO’s Pegasus malware suite. Researchers identified text message phishing that led to malicious web pages, as well as HTTP man in the middle attacks against their mobile devices. Once the target was successfully directed to the malicious site, A collection of zero-day vulnerabilities were used to compromise the phone with the NSO malware.

NSO is an Israeli company that specializes in building malware and other cybersecurity tools for governments. As you can imagine, this specialization has earned NSO the scorn of quite a few organizations. NSO claims to have a policy framework in place that allows them to evaluate and terminate the use of their software when it is deemed illegal or abusive, but due to the nature of their contracts, that process is anything but transparent. Continue reading “This Week In Security: A Digital Café Américain, The Linux Bugs That Weren’t, The Great Nation, And More” →

CPU Showdown For Pancakes

October 11, 2019 by Al Williams 27 Comments

If you ask people how they rate as a driver, most of them will say they are better than average. At first, that seems improbable until you realize one thing: people judge themselves by different criteria. So Sally thinks she’s a good driver because she goes fast. Tom’s never had a wreck. Alice never gets lost. You can see the same effect with CPUs. Some are faster or have more memory bandwidth or more instruction issues per cycle. But [Andrew] and [Scharon] at Tom’s Hardware wanted to do the real test of a CPU. How well can it cook pancakes? If you want to know, see the video below.

While your CPU might be great for playing video games, it has a surprisingly small cooking surface, so the guys needed a very small pan. The pan had grooves in it, so they slathered it with thermal grease. We doubt that’s food-grade grease, either. Continue reading “CPU Showdown For Pancakes” →

Europeans Now Have The Right To Repair – And That Means The Rest Of Us Probably Will Too

October 9, 2019 by Jenny List 142 Comments

As anyone who has been faced with a recently-manufactured household appliance that has broken will know, sometimes they can be surprisingly difficult to fix. In many cases it is not in the interests of manufacturers keen to sell more products to make a device that lasts significantly longer than its warranty period, to design it with dismantling or repairability in mind, or to make spare parts available to extend its life. As hardware hackers we do our best with home-made replacement components, hot glue, and cable ties, but all too often another appliance that should have plenty of life in it heads for the dump.

Czech waste management workers dismantle scrap washing machines. Tormale [CC BY-SA 3.0].

If we are at a loss to fix a domestic appliance then the general public are doubly so, and the resulting mountain of electrical waste is enough of a problem that the European Union is introducing new rules governing their repairability. The new law mandates that certain classes of household appliances and other devices for sale within the EU’s jurisdiction must have a guaranteed period of replacement part availability and that they must be designed such that they can be worked upon with standard tools. These special classes include washing machines, dishwashers, refrigerators, televisions, and more.

Let’s dig into the ramifications of this decision which will likely affect markets beyond the EU and hopefully lead to a supply of available parts useful for repair and beyond.

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