Chartoni: my corrugated cardboard hifi speakers

A while ago Jan Wessel Hovingh gave me a Raspberry Pi Zero as a thank you gift for a talk I gave at the University of Applied Sciences in Leeuwarden. I decided to create my own streaming audio speakers with this Pi. After quite a bit of DuckDuckGoing, quite some help from many wonderful people and some work it’s done: two hifi speakers made out of layers of corrugated card board, powered by a Raspberry Pi.

The speakers

The design of the speakers is a mashup of two designs by Tony Gee of Humble Home Made Hifi. The choice of drivers and the dimensions of the box are based on the DD8-MkII. Inspired by the design of the Otello I moved the bass reflex port to the front. I like this asymmetrical layout better. I ordered the crossover filters from Humble Home Made Hifi.

The box

The box is made out of about 80 layers of 4.5mm thick high quality corrugated cardboard, glued together with common wood glue. Yes, there is such a thing as high quality card board. I ordered mine at the wonderful and very helpful Jansen-Wijsmuller & Beuns, Wholesale of bookbinders, restoration and conservation materials. The insides of the speakers are covered with CTK Vibrodamping. I used one of the lasercutters we have at our university to cut everything into its exact shape. If you need it, you can download all the EPS files right here. I created these by hand. Later on I learned that there’s software that can do this for you …

The amp

There are a few sounds cards for the Raspberry Pi Zero that convert digital stuff to analog sound, like the Allo Miniboss. Instead of buying this Miniboss and sticking to the plan I bought a new Raspberry Pi 3 with a Dion Audio LOCO DAC-AMP.

I tried a few different software distributions to run on the Pi. I really liked Moode Audio. Lots of features in an easy enough web interface. But in the end I couldn’t get it to work for my set up. So now everything runs on a simple Raspbian Stretch Lite with only the incredible Shairport-Sync installed, since Airplay is the only way we stream music. I tweaked the Shairport-Sync settings a little bit. For higher quality sound I turned on interpolation = "soxr", I set output_rate = 44100 and output_format = "S32". I tried higher numbers for the output_rate but the Pi couldn’t handle these, and I can’t hear the difference anyway. I also set allow_session_interruption = "yes" so we can intervene if someone else is playing annoying music. And I called the Airport network Χαρτόνι, which means cardboard in Greek.

The case

I had some cardboard left so I designed and built a case for the LOCO as well. The idea was that diagonals would allow for bigger openings so the Pi will be able to get rid of the heat, while it stays a bit dust free. I’m not sure about the dust, but the heat is definitely fine. When idle the temperature is around 44°C, and it doesn’t get over 50°C when we play music. The EPS for this case can be found in this zip as well.

Thank you

I want to thank Dave Krooshof for helping me out with about everything in this project. Without him I would not have been able to make this thing. And thank you to Jeanet Verwoerd from Jansen-Wijsmuller & Beuns who kept helping me patiently with my impossible questions. Also big thank you to Tony Gee of Humble Home Made Hifi who didn’t laugh at the idea of building cardboard speakers, and who later answered all kinds of questions via email. And of course for sharing his wonderful designs. Thank you as well to Miquel Blauw of Dion Audio who answered all my emails and really helped me out in many different ways. And of course a huge thank you to all the people of the internet who share their knowledge about all the extremely nerdy stuff I needed on their blogs, on github and on all kinds of fora.

And now I still have this Raspberry Pi Zero.

My new research blog

I created a new research blog. That’s where I’ll be documenting my master research. Which means that I will be mostly publishing over there. This blog will probably be even more sleepy that is has been. So if you’re interested in the research I’m doing in accessible web design you can better move over there. You can subscribe to that blog via RSS if you want to.

Exclusive Design at Beyond Tellerrand

The amazing Marc Thiele invited me to give a talk at his incredible Beyond Tellerrand conference in Berlin. The line-up was simply amazing. Mina Markham did a beautiful talk which is worth your time for so many reasons. You should all watch it. And I absolutely loved the talk that Paula Sher did. She is even more fantastic on stage that she is on Netflix.

More after the click

An extended report of the first Exclusive Design Challenge

I published a much more graphically appealing and much more detailed report of the very first The Good, The Bad, and The Interesting Exclusive Design Challenge. It’s filled with the beautiful pictures that Gitta Schermer took of the event. And I added some graphs as well!

Technical details?

The First The Good, The Bad, and The Interesting Exclusive Design Challenge

In the past year I recorded conversations with an eclectic mix of 40 designers and published them on my site under the moniker The Good, The Bad, and The Interesting (mostly in Dutch). This summer I decided to invite all my guests for the very first The Good, The Bad, and The Interesting Exclusive Design Challenge. This weekend 16 people showed up for this event. I’m probably biased, but it was fantastic. (A more detailed report of this event can be found here)

Tel me more!

Can Exclusive Design make the web more accessible?

Theoretically the web is in itself accessible for people with disabilities. The theory is wonderful. Yet in practice we’re not there yet.


Exclusive Design Principles

I learned from Jeremy Keith (who learned it from Cennydd Bowles, who learned it from Jared Spool) that good design principles are reversible. To test if a design principle works, the exact opposite rule should work as well. I decided to put the Paciello Group’s Inclusive Design Principles to the test. What happens if you reverse all these principles? They should result in something that you could name exclusive design principles.

What are they?

Design meets Disability

I read quite a few books about designing for accessibility in the last few months. Most of them were about so called inclusive design, and most of them were focused on designing inclusively for the web. While I learned a lot, and while I thoroughly enjoyed all the books I read, there was one book that stood out: Design Meets Disability by Graham Pullin. It stood out because of its different approach to designing for accessibility.

That’s interesting

I created Journa11y

I created a first iteration of a little tool I plan to use. Or to be more precise, a tool I hope you will use every now and then. It’s inspired on a project Manon Mostert – van der Sar made, where she asked makers in het maker’s lab to log their failures in a booklet. I ask you to log design decisions that influence accessibility on a website. And I call it Journa11y.

What does that mean?

Why I do accessibility

One of my coaches at the Design Master course asked me what I mean when I use the term accessibility. I tried to explain what I mean by quoting a few sources that explain it quite clearly (I hope). But that post doesn’t necessarily explain why I chose accessibility as my subject. There are three reasons why I like accessible web design. It’s possible, it’s a friendly thing to do, and it’s not very hard.

Easy enough

What does accessibility mean?

One of my coaches at the Master Design course I’m following wondered what I mean when I say accessibility. I’ve heard the term so often that I forgot that the definition I use is not common at all. In this blog post I’ll try to explain what I mean by looking at a few definitions used by different organisations.

So what’s accessibility

Creating awareness around accessibility

When it comes to making websites accessible, there’s a lack of awareness among the people who design and build websites. At least, that’s what I have to conclude after speaking to quite a few different specialists. I spoke to people who build websites, who design them, who lead teams, who use websites with a screenreader, who study to become a web designer, and I spoke with accessibility specialists in different fields. They all agree. There is a lack of awareness. People don’t know it is possible to create websites that work for everybody. And if they’ve heard of accessibility they think it’s hard to do.

But is it?

An Atlas of Reasons

I made this Atlas of Makers because I want to understand why people make things. My assumption is that if I understand the different reasons it’s easier to find the right tone of voice when I want to teach them something. In this chapter I think it makes some sense to make a distinction between people who make things for others and people who make things for themselves. But it’s not really possible to fit people into these exact boxes. For instance, some people have a personal obsession with a certain subject, but at the same time they want to share the beauty of this obsession with others. So, even when it’s not binary at all I decided to order this chapter about reasons why people make things in my Atlas of Makers by people who make things for others, and people who make things for themselves.

There are more ways to order things

An Atlas of Tools

It was to be expected that such an eclectic mix of people who make things uses an eclectic mix of tools. If this chapter about tools in my Atlas of Makers shows one thing, it is that people all have different needs.

Not very shocking, right?