Design News, January 2013

Issue link:

Contents of this Issue


Page 19 of 81

MADE BY MONKEYS Snafus With the Speakers In this story, my own products were made by monkeys. My company had a great staff that assembled the radio receivers that we sold. Staff members were able to follow instructions and use their initiative when something unexpected arose. Sometimes, however, the instructions did not reach everyone. Our top-quality radio used an oak cabinet. Inside the cabinet we mounted a four-inch speaker. The inside of the cabinet was just slightly larger than the speaker, typically by 1/8 inch. The speaker could be dropped into place and then held with four wood screws. Because wood is not as precise as metal, occasionally the inside of the cabinet was smaller than the frame of the speaker. I had instructed the staff to bring these few cabinets to my attention. Since I had more physical strength than anybody on my staff, I took a sharp knife and cut the inside of the cabinet so that the speaker would fit, and then they mounted the speaker in the normal fashion. One day, someone from the office was helping to mount the speakers. She was not told about those cases where the speaker would not fit. Instead of giving the cabinets to me, she bent the frame of the speaker so that it would fit. Needless to say, the cone was distorted and I considered the speaker destroyed. I checked and found another cabinet with a bent speaker and had it replaced. A month later, a new radio was returned with the complaint of excessive distortion. To my dismay, the speaker had been bent to fit the cabinet. Our speakers were made in China and supplied by a local distributor. Once, when our supplier was out of stock, we bought a shipment of very high quality speakers from another source at a good price. The magnets were heavy and the speakers sounded great. We installed them into the cabinets and sold the radios. A few months after shipping, some of the radios were returned marked "no sound." Upon examination, we discovered that the magnet had fallen off, probably because the radio was dropped. Then it would grab the frame, which was made of steel. In other radios the speaker appeared normal, but with a sharp pull, the magnet could be removed. There was no sound because the voice coil was pinched between the magnet and the frame. It seems that the magnet was glued to the frame, carefully centered so that the voice coil could move freely through the steel projection from the center of the magnet. When the glue aged, it lost its strength and the magnet either fell from the frame, or moved sufficiently to pinch the voice coil. The speaker was well designed and carefully built, but somebody substituted cheap glue that didn't have the strength to hold the magnet. Or perhaps the glue was not properly applied. Clearly, monkey business! — FRANK KARKOTA Made by Monkeys highlights products that somehow slipped by the QC cops. Email your stories to Rob Spiegel at Design News | JANUARY 2013 | www.d esign n –18–

Articles in this issue

Links on this page

Archives of this issue

view archives of DesignNews - Design News, January 2013