Make Your Own Loudspeaker From Scratch

A loudspeaker is a vital component of every device that plays sound, but while its operation is simple, it’s a surprisingly difficult device to build. [Rvanderouderaa] has made an Instructables post showing a speaker design that it’s claimed, had an impedance that varies by volume (Dutch language, Google Translate link).

In all moving-coil speakers, a coil of wire is held in a radial magnetic field. To this is attached a cone, and when a current is passed through the coil the whole thing moves to create the sound. The tricky part of making one comes in making the cone itself, and in particular the suspension system that holds it in place while allowing it to move backwards and forwards. It’s normal for these components to be moulded from thick paper.

This design uses a 3D printed frame and cone, with the 3D printing providing excellent rigidity. The suspension system is a circular corrugated sheet, and it’s made in this case using papier-maché made from wet toilet paper, and a 3D printed mould. We particularly like this technique.

This is an impressive build, simply for having made a recognizable and working speaker in the first place. There’s no demo video so we have no idea how it sounds, but for us the point is more in the construction than the reproduction.

If speakers interest you, we’ve taken an in-depth look at them in the past.

Make That Smart TV Into A Computer

The smart TV is a fixture in most houses, variously an entertainment portal, corporate data gathering tool, or sometimes an outright spy. It’s a nice monitor with a computer built in, so can that computer be released to do something else? It’s a question [Xen’on] is answering, on an Android-based TV.

The guide is not too different from many others relating to Android phones, with a few quirks. An Android Debug Bridge (ADB) connection is established, root access is gained using Shizuku, and then it’s a case of installing a more conventional Linux front end with the Openbox window manager through Termux. There are some TV-specific things to do with handling power cycles, but the TV is now a usable Linux box.

It’s always good to see someone retrieve the Linux underneath a locked-down device, but the system spec tells the real story. By the looks of things this TV is a few years old as it had an Android version that’s a bit long in the tooth, and thus it also packs an aged version 4.x kernel. Couple that with a more seat-of-your-pants experience compared to a regular distro where many of the annoyances are taken care of, this isn’t an easy route to a trouble free desktop. Instead it has a lot of potential for making the TV what it was intend to be, an entertainment device. Merely one that gives much more software freedom.

Meanwhile, this isn’t the first Termux guide we’ve seen.

Pi Media Player With VCR Vibe Is Perfect For CRTs

If you have a TV and a Pi, you have the workings of a media center, and you’re not exactly short on options for software. But options are good, so here’s one more by [Anthony Caccese] — a player called 240-MP that explicitly targets CRTs with its retro stylings, released under the GPLv3 license.

Don’t let the name fool you, though. While the blue-and-white styling is very evocative of 90s VCRs, the output isn’t limited to 240p. If you’re running it into a vintage CRT over composite, as [Anthony] does, sure, it’ll do that. If you want to use HDMI on a modern TV, however, that’s an option too, in 4K if that’s your jam. Higher resolution video will need a beefier Pi, of course, but MPV can handle the files, and ultimately this is a wrapper for MPV. You still get the vintage styling, which can do green-and-black as easily as white-and-blue, as well as whatever custom color scheme you want to define. It might not look quite as good if it’s not on a display tube, but we could see this as a good fit for a plasma TV, too.

As you can see in the demo video embedded below, the player is equally happy listing and playing local files — including playlists — or streaming via a PLEX server. Other add-ons, for example to launch emulators, may be forthcoming. Of course, if you’re not willing to wait you could always code them yourself.

Given the roots of this project in old VHS interfaces, we’re somewhat surprised there doesn’t seem to be an option for control via physical tokens. We’ve already seen projects that try and replicate that portion of the VCR magic, though. If it’s not the tapes you miss from back in the day, you can also simulate cable TV.

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Bring Back Your Bose With An ESP32

It’s become a familiar theme over the last couple of decades — hardware is rendered useless when its manufacturer pulls the cloud service on which it depends. This is particularly annoying when the device is something which shouldn’t need a cloud service to run in the first place, and several manufacturers have found themselves in hot water because of this.

Somewhere in between is the Bose SoundTouch speaker system, which includes a set of six internet radio preset buttons. In early May the service behind them was shuttered, and now here’s [Tostmann] with an ESP32 firmware to bring them back.

As you might imagine, it’s a device that emulates just enough of the now-defunct Bose cloud service to keep the speaker happy, but it has a clever trick up its sleeve. Normally these hacks rely on DNS redirects at the router, but this one avoids that thanks to a diagnostic interface on the Bose unit that allows the rewriting of the server address. The ESP32 does this with its own address, and the speaker is none the wiser.

We like this hack, because of its ingenuity, and because it saves yet another orphaned cloud product from becoming e-waste. This isn’t the first time we’ve seen a manufacturer on the naughty step for these practices.


Header image: TAKA@P.P.R.S, CC BY-SA 2.0.

The History Of Altec Lansing

If you bought computer audio hardware a few decades ago, you may remember coming across products from Altec Lansing. That you probably haven’t thought of that name in some time doesn’t surprise us, the company has not fared well in recent years and has changed hands multiple times. [The Last Shift] tells the company’s history in a video you can watch below.

James Lansing started Lansing Manufacturing, offering high-end speakers for the fledgling “talkie” movie industry. It had some success, but the depression put them on shaky footing. Meanwhile, a company named All Technical Service Company, or Altec, was a large organization that serviced Western Electric movie theater equipment. Flush with cash, they merged with Lansing Manufacturing to form Altec Lansing. With a large infrastructure and Lansing’s engineering, they became a significant supplier to the military during World War II.

After the war, the company produced a landmark theater speaker system that became the gold standard in theater audio. However, Lansing didn’t like the big company environment and left to found a company that bore his full name, James B. Lansing, which you may know as JBL.

Altec Lansing continued to grow. However, a series of mergers and sales starting in 1969 caused the Altec Lansing company to decline. By the 1990s, Altec Lansing was making cheap PC speakers. A far cry from the gold-standard massive speakers made by the company during its heyday.

We love the history of technology and the people that drove them. Bing Crosby, for example. Or the lesser-known heroes like Edwin Armstrong.

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A Digital Audio Recorder For TOSLink

Every now and then in our travels we come upon a project with such an obvious need that it’s almost a surprise nobody has thought of doing it before. So it is with [Elehobica]’s project, an audio recorder for S/PDIF audio streams. It’s the device you could have used, years ago!

S/PDIF, or its optical fiber cousin TOSLINK, is the digital output you’ll find on the back of Hi-Fi equipment, it’s a serial encoding of an uncompressed digital audio data stream dating from the era when CDs were new. Its relative simplicity may be what’s given it longevity — it’s easy to implement so it plugs into pretty much everything.

Perhaps back in the day it might have been a pain for an 8-bit microprocessor to handle, but in 2026 it’s no bother for a Raspberry Pi Pico. The project is a small PCB with the Pico, a few interface components, and an SD card socket, and it sends what it hears on the input to the card as WAV files. We particularly like its smart sample rate and bit depth detection, and the way it cuts up tracks based on periods of silence. If you work with SPD/IF, this is going to be a useful tool.

Perhaps it could even be fed with a laser!

A Tube Amplifier That’s Oven Ready

The problem with tube based audio is that it has so often been hijacked by people for whom the bragging rights of having a tube amplifier outweigh the benefits, or the sheer fun of building the thing. [Bettina Neumryr] makes a speciality of building projects featured in old electronics magazines, and her latest, a tube amplifier from 1955, is a fantastic antidote to the gold-plated silliness of audiophile tube amplifiers.

Design wise it’s relatively straightforward, with a preamplifier before a two-tube transformerless splitter circuit driving a push-pull output. She dives into the circuit a little, noting its feedback circuit to the cathode of the first splitter tube. There’s an accompanying power supply, a classic tube rectifier design that incorporates a hefty low-pass filter with a giant choke.

We particularly like her choice of chassis — while it’s possible to pay silly money for a tube chassis in 2026 she’s taken a much more down to earth approach with a pair of baking trays. We’re being honest here, they look surprisingly good. Component choices are limited by what’s available so most parts come from the junk box including the output transformer which causes her issues later. There’s a lot of mumbo-jumbo about tube amplifier layout, and she wisely sidesteps some of it.

The result after a few mishaps and a bit of unintended oscillation, is an amp which shows promise, but has distortion due to that transformer. We think she’ll have no problems sourcing a better one, which should bring that distortion figure into the acceptable range. You can watch the whole video below the break, and if that’s got you hooked, you can see one of our own youthful follies.

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