For the past 4 years I have been a resident at Ponyride in Corktown Detroit. Each year we have an open house/holiday market. This year, the entire building was crammed with merry Folks. I talked with my hands, lost my voice, and made some great connections. Thank you to all who came out this year, I hope to see you again soon.
Early on, the material of choice for Pingree's frame was extruded aluminum. It is the perfect material for this application. But its not easy to prototype it as minimum orders of a custom extrusion start in 1000 pound batches. After deep thought, I decided to try and make my own small batch of extrusion in my shop. To do so, I needed a way to dimension and carve profiles in long pieces of aluminum. The solution I came up with was to make an over elaborate router/mill out of some shop scraps. In short, It worked really well, sprayed hot aluminum chips all over my shop, all while making a horrifying sound. The photo below is the finished product.
Homemade Aluminum Mill & Mandrill Bender
After a successful short run of milled aluminum I cut it to length and added an indexing hole to allow me to accurately bend the radii in a repeatable manner. The mandril I used was actually 3D printed part from shape ways. After 10-12 bends, it lost its accuracy and the profile of aluminum began to flare out. I was able to get 2 successful prototypes out of it, so I didn't leave disappointed. After the bending there was still more work to be done. Fixtures were made to accurately drill and tap the connection piece between both halves of the frame.
Above is a video I sent to my father explaining the construction of the mill. Below is a slideshow of the rest of the steps to get to the final prototype.
Another substantial improvement in functionality and sound. I made a few of these prototypes and was pretty certain that I was going to stop here. Luckily I didn't. The bass response greatly increased at this point. Also, everything sounded significantly less "muddy." Mainly because in this model, I discovered the most important factor in sound quality. It wasn't the species of wood, or the thickness. It was actually the proportions of the panels and how freely they can vibrate. There was nothing attached to the panels at this point. They could sing away without restriction. The amplifier didn't have to work as hard and the battery/amp combo I recently rigged up lasted much longer on one charge. I was taking this everywhere with me. Watching movies with it. Going to the beach. Bringing it to class. Even playing white noise through it while I slept.
The lasercut plywood frame just had to go. It was labor intensive, inconsistent, and overall, the construction didn't allow for expansion and contraction. The electronics I put together worked well, but not good enough. It was under powered and would distort at high volume. My search for answers continued.
At this point I realized I was severely undereducated in the world of electronics. I had only a rudimentary understanding of the inner workings of a portable audio product. I spent endless hours gathering information on rechargeable batteries, class D amplifiers, and Bluetooth modules. After dissecting a few similar Bluetooth speakers, I began trying to source and build my own amp/battery/transducer combo. I came up with a solid test module that I used for the next few prototypes. My soldering skills improved tenfold at the expense of overheating components with clumsy technique. The result: a unique method I'm quite proud of.
Buy some tools. Practice makes perfect. The internet is a powerful resource.
This is where things got interesting. Pingree grew, and so did its sound. Overall volume increased dramatically. The addition of a rechargeable lithium ion battery allowed for hours of playback. The rectilinear form seemed reminiscent of a boom box and it seemed like a familiar object already. I began toying with the idea of running a kickstarter for this at this point. Everyone who saw it and heard it loved it. My confidence grew.
Bigger is better. Rectangles are the way to go. Two transducers are way better than 1. Maple FTW. Volume knob?
The second prototype had a cousin. It was much smaller, and used only 1 transducer. Although I did not end up developing it further, it is still worthy of sharing. I was thinking small, and using AAA batteries instead of a rechargeable alternative, I saw this living on someones nightstand or desk. A bit of a novelty, as the sound quality suffered with its size. There were however, some intriguing ideas at play. An integrated phone holder that doubled as a cord wrap. Maybe I will revisit this someday.
The spark that lit the fire for Pingree was actually a challenge from Drinks by Design. Essentially, the challenge was to find a way to use reclaimed wood to create a marketable product. A head-scratching challenge to say the least. I presented my first prototypes that night to a crowded room full of nice people. Despite the loud crowded room, I received many positive reactions to the prototypes I brought. I left feeling motivated.
After a long night in my shop I finished the very first prototype of Pingee. Then, it was just an experiment. Crudely designed with only 1 transducer and an under powered amplifier. Essentially a wooden box that vibrated. It worked impressively well. I couldn't believe what I was looking at. I marveled over the absurdity that a flat wooden surface could play Red Hot Chili Peppers at an audible and pleasant volume. My mind has been occupied with this facination ever since.
My very first ideas for this wooden speaker thing I couldnt quite explain to anyone. Wallmounted? Big? Small? Portable? Stationary? Knobs? I began to dissolve down some basic proportions.
Make a working prototype so you don't have to talk with your hands all the time.