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

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.]
Continue reading “Building The World’s Best DML Speakers For Under $115”

Hackaday Links Column Banner

Hackaday Links: September 15, 2019

It’s probably one of the first lessons learned by new drivers: if you see a big, red fire truck parked by the side of the road, don’t run into it. Such a lesson appears not to have been in the Tesla Autopilot’s driver education curriculum, though – a Tesla Model S managed to ram into the rear of a fire truck parked at the scene of an accident on a southern California freeway. Crash analysis reveals that the Tesla was on Autopilot and following another vehicle; the driver of the lead vehicle noticed the obstruction and changed lanes. Apparently the Tesla reacted to that by speeding up, but failed to notice the stationary fire truck. One would think that the person driving the car would have stepped in to control the vehicle, but alas. Aside from beating up on Tesla, whose AutoPilot feature seems intent on keeping the market for batteries from junked vehicles fully stocked, this just points out how far engineers have to go before self-driving vehicles are as safe as even the worst human drivers.

The tech press is abuzz today with stories about potential union-busting at Kickstarter. Back in March, Kickstarter employees announced their intent to organize under the Office and Professional Employees International Union (OPEIU). On Thursday, two of the union organizers were fired. Clarissa Redwine, who recently hosted a Hack Chat, was one of those released; both she and Taylor Moore are protesting their terminations as an illegal attempt to intimidate Kickstarter employees and keep them from voting for the union. For their part, Kickstarter management says that both employees and two more were released as a result of documented performance issues during the normal review cycle, and that fourteen employees who are in favor of the union were given raises during this cycle, with three of them having been promoted. There will no doubt be plenty more news about this to come.

Would you pay $900 for a Nixie clock? We wouldn’t, but if you choose to buy into Millclock’s high-end timepiece, it may help soften the blow if you think about it being an investment in the future of Nixie tubes. You see, Millclock isn’t just putting together an overpriced clock that uses surplus Russian Nixies – they’re actually making brand new tubes. Techmoan recently reviewed the new clock and learned that the ZIN18 tubes are not coming from Czech Republic-based Dalibor Farný, but rather are being manufactured in-house. That’s exciting news for Nixie builders everywhere; while Dalibor’s tubes are high-quality products, it can’t hurt to have a little competition in the market. Nixies as a growth industry in 2019 – who’da thunk it?

We ran across an interesting project on Hackaday.io the other day, one that qualifies as a true hack. How much house can you afford? A simple question, but the answer can be very difficult to arrive at with the certainty needed to sign papers that put you on the hook for the next 30 years. Mike Ferarra and his son decided to answer this question – in a circuit simulator? As it turns out, circuit simulators are great at solving the kinds of non-linear simultaneous equations needed to factor in principle, interest, insurance, taxes, wages, and a host of other inflows and outflows. Current sources represent money in, current sinks money paid out. Whatever is left is what you can afford. Is this how Kirchoff bought his house?

And finally, is your parts inventory a bit of a mystery? Nikhil Dabas decided that rather than trying to remember what he had and risk duplicating orders, he’d build an application to do it for him. Called WhatDidIBuy, it does exactly what you’d think; it scrapes the order history pages of sites like Adafruit, Digi-Key, and Mouser and compiles a list of your orders as CSV files. It’s only semi-automated, leaving the login process to the user, but something like this could save a ton of time. And it’s modular, so adding support for new suppliers is a simple as writing a new scraper. Forgot what you ordered from McMaster, eBay, or even Amazon? Now there’s an app for that.

Hackaday Podcast 034: 15 Years Of Hackaday, ESP8266 Hacked, Hydrogen Seeps Into Cars, Giant Scara Drawbot, Really Remote RC Car Racing

Elliot Williams and Mike Szczys wish Hackaday a happy fifteenth birthday! We also jump into a few vulns found (and fixed… ish) in the WiFi stack of ESP32/ESP8266 chips, try to get to the bottom of improved search for 3D printable CAD models, and drool over some really cool RC cars that add realism to head-to-head online racing. We look at the machining masterpiece that is a really huge SCARA arm drawbot, ask why Hydrogen cars haven’t been seeing the kind of sunlight that fully electric vehicles do, and give a big nod of approval to a guide on building your own custom USB cables.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 034: 15 Years Of Hackaday, ESP8266 Hacked, Hydrogen Seeps Into Cars, Giant Scara Drawbot, Really Remote RC Car Racing”

Hackaday Celebrates 15 Years And Oh How The Hardware Has Changed

Today marks exactly 15 years since Hackaday began featuring one Hack a Day, and we’ve haven’t missed a day since. Over 5,477 days we’ve published 34,057 articles, and the Hackaday community has logged 903,114 comments. It’s an amazing body of work from our writers and editors, a humbling level of involvement from our readers, and an absolutely incredible contribution to open hardware by the project creators who have shared details of their work and given us all something to talk about and to strive for.

What began as a blog is now a global virtual hackerspace. That first 105-word article has grown far beyond project features to include spectacular long-form original content. From our community of readers has grown Hackaday.io, launched in 2014 you’ll now find over 30,000 projects published by 350,000 members. The same year the Hackaday Prize was founded as a global engineering initiative seeking to promote open hardware, offering big prizes for big ideas (and the willingness to share them). Our virtual connections were also given the chance to come alive through the Hackaday Superconference, Hackaday Belgrade, numerous Hackaday Unconferences, and meetups all over the world.

All of this melts together into a huge support structure for anyone who wants to float an interesting idea with a proof of concept where “why” is the wrong question. Together we challenge the limits of what things are meant to do, and collectively we filter through the best ideas and hold them high as building blocks for the next iteration. The Hackaday community is the common link in the collective brain, a validation point for perpetuating great ideas of old, and cataloging the ones of new.

Perhaps the most impressive thing about the last 15 years of Hackaday is how much the technological landscape has changed. Hackaday is still around because all of us have actively changed along with it — always looking for that cutting edge where the clever misuse of something becomes the base for the next transformative change. So we thought we’d take a look back 15 years in tech. Let’s dig into a time when there were no modules for electronics, you couldn’t just whip up a plastic part in an afternoon, designing your own silicon was unheard of, and your parts distributor was the horde of broken electronics in your back room.

Continue reading “Hackaday Celebrates 15 Years And Oh How The Hardware Has Changed”

Eagle Reborn: F-15 Simulator From A Wreck

This story started all the way back in September 12, 1981, when an F-15C aircraft’s landing attempt at Soesterberg Airbase during an airshow went completely FUBAR and the airframe was scrapped. The forward fuselage section was sold and eventually ended up with [Gene Buckle] who began work on creating a fully accurate F-15C simulator using these parts. He has blogged about his progress since 2009 over at the project website.

The F-15C was number 80-0007, which at the time of the crash had flown only 9.5 hours total, making it a very early retirement for an incredible fighter jet. But now the Eagle is back, or at least part of it: [Gene] managed to get the whole system into a state where the instrumentation and controls work again, using the original computer systems and instruments where they were still usable. You can find the YouTube video embedded after the break as well.

Detailed technical information on the F-15 series and this simulator build can be found on the project site, which is awesome both for F-15 fans and those who are into really accurate simulators.

Continue reading “Eagle Reborn: F-15 Simulator From A Wreck”

New Part Day: The $15 ESP32 With Cellular

Cruise around AliExpress for long enough and you’ll find some interesting new hardware. The latest is the TTGO T-Call, an ESP32 breakout board that also has a cellular modem. Yes, it’s only a 2G modem, but that still works in a lot of places, and the whole thing is $15.

On board the TTGO T-Cal is the ESP-WROVER-B, the same module you all know and love that features a dual-core ESP running at 240 MHz with 4 MB of Flash and 8 MB of SRAM. Add to this WiFi and Bluetooth, and you have a capable microcontroller platform. Of note is that this board includes a USB-C port, ostensibly wired so that it behaves like a normal USB micro port. That’s neat, 2019 is the year USB C connectors became cheaper than USB micro connectors.

In addition to the ESP32 module, there’s also cellular in the form of a SIM800 module. This module has been around for a while and used in many, many cellular-connected projects and products like the ZeroPhone. This module is only a 2G module, and that’ll be going away shortly (if not already) in built-up areas, but this can serve as a building block for modules that have more Gees than a 2G module. That said, if you’re looking for a WiFi and cellular bridge for fifteen bucks, you could do a lot worse for a lot more money.

Hackaday Podcast 015: Going Low Frequency, Robotic Machines, Disk Usage For Budgets, And Cellphones Versus Weather

Hackaday Editors Mike Szczys and Elliot Williams discuss the highlights of the great hacks from the past week. On this episode we discuss wireless charging from scratch, Etch-A-Sketch selfies, the robot arm you really should build yourself, bicycle tires and steel nuts for anti-slip footwear, and bending the piezo-electric effect to act as a VLF antenna. Plus we delve into articles you can’t miss about 5G and robot firefighting.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 015: Going Low Frequency, Robotic Machines, Disk Usage For Budgets, And Cellphones Versus Weather”