Taking a modern approach to 80s Hip-Hop by TDK's PiezoListen™

We have dedicated ourselves to the guiding principle: Contribute to culture and industry through creativity. Our more recent boombox project with hacker royalty Joe Grand, also known as Kingpin, embodies the three core values of our motto – culture, industry, and creativity. Blending the hip-hop culture with break-dancers, cutting-edge manufacturing techniques with super thin speakers, and a nod to TDK’s past are all included. We are delighted to claim that inspiration for the entire project was inspired by those speakers – our PiezoListen™ speakers.

The birth of an idea

We initially got in touch with Grand with the hope that he could create a new project based on our parts. After combing through our product portfolio, he found our PiezoListen™ speakers, which are widely used in the automotive industry, and it all came together. He leaped at the chance. Being an avid lover of hip-hop music and growing up listening to it play from TDK-branded cassette tapes, he came up with a concept that would interest not only the engineering community but also the general public.

“Growing up in the 80s, I remember clearly the sounds that were coming out of New York,” said Grand. “I had a friend with a boombox, and we’d listen to hip-hop innovators like The Fat Boys and Grandmaster Flash while walking around the neighborhood. People must have thought we were crazy; I thought we were the coolest thing ever.”

His project was to recreate his childhood memory by building a boombox – one that has several high-tech twists and is evocative of those gigantic monsters from the 80s. As it would be a one-off, the design of the front panel would pay homage to street art culture – making it an original masterpiece.

Boomboxes were closely related to TDK because we were one of the major cassette tape vendors during the 70s and 80s when cassette players were at their peak. That would be the seed for one of Grand’s more original design concepts, but we’ll come to that later.

Cutting-edge manufacturing

If he wanted to create the world’s thinnest boombox, the PCB would need to contain all the electronics, including the speakers. The board would, therefore, be completely exposed. Grand’s vision was for the front of the boombox to be aesthetically appealing and for the back to be clean and simple. He made the decision to cover up all of the traces on the PCB's inner layers so that nobody could see them. This would need the usage of via-in-pad, in which the interlayer connections of the PCB are constructed directly into the landing pads of the component. This is commonplace in modern consumer electronics, but it was unclear whether it could be stretched to the large boombox dimensions.

Many of the vintage boomboxes included LEDs. Although most were purely for decoration, some lights were functional, indicating volume levels, for example. Grand wanted the PCB in his boombox to actually light up. Instead of drilling through-holes in the PCB for the LEDs, he asked the manufacturer whether they could mill holes only partly through the PCB. In this manner, when the LEDs were inserted from the back, the light would diffuse on the front through the PCB material. When the manufacturer confirmed that they could do controlled-depth milling, incorporating capacitive touch buttons for operating the boombox (play, pause, volume, etc.) would also be possible.

To protect the components and battery, which is the thickest element of the system, Grand added a simple frame bringing the total thickness of the boombox to less than a finger width.

Joe Grand’s TDK boombox

And here is the final product - the World’s thinnest boombox.

The ability to incorporate art, music and engineering was, in Grand’s opinion, the most interesting aspect of the project. He said: “It was a lot to take on, but that is what intrigued me about it, and I believe that’s what will also excite other people.”