*For twice the price and half the quality.

I was in highschool and wireless speakers that are almost basic accessories nowadays were a new thing. I wanted one but I didn’t have the money for it. I met here with the effects of a ground loop in practice for the first time. It was in the form of a loud buzzing sound when using the bluetooth module. It took me years to learn what caused the problem that was making me mad back then.

Although I researched it as best as I could there were many gaps in my knowledge. I struggled to calculate the running time of the system as the amplifier that I bought stated that it has a power of 200W, but when measured it barely consumed 10% of that. I also didn’t know that lithium has a way better capacity to weigth ratio and went with car batteries.

If you can’t guess it from the picture, it really was home made. Screwed / hotglued together from scrap wood and acrylic with some bootleg Meccano Sets from my childhood toys. Needless to say it also sounded bad… And of course it did, I did not know about waves, resonance or sound engineering at all. Still, I saw it as a success as people were enjoying it. I decided to make a second version. This time I wanted to make it look and sound better. Last year of high school was about to start and I had to finish it for the last class trip. This time I bought the wood and started working right away.

I also figured out that the buzzing was only present when the amplifier and the bluetooth module was on the same supply, so I solved it by packing in two 9V batteries and supplied the bluetooth module from that. This version also contained a USB port for charging devices and a roof window to show off all of this.

It was a success. I impressed my teachers and classmates with it.

Placeholder for when I find the pictures of the second version

It was used a few more times but it got decomissioned way too soon. It was heavy, diffucult to use and still was not the best sounding speaker. This combined with the end of highschool which also brought changes in my life made it barely used. Later I took it apart and built half of it into my car. At this time I understood the concept of DC decoupling and it worked well for years in my car until I sold that too.

I put aside some speakers and a box for a version 3.0. This time I had the knowledge, the best parts, tools and I even made CAD models this time. I had everything but the time for it. I gave the set to one of my friends to practice electronics with.

Maybe when I retire...