Backer’s update #8: the first kien speakers

April has been a very decisive month here at Kien HQ and we are very excited to share everything that has happened with you.


BOARDS

On April 9th we received the two packages containing the 180 prototype printed circuit boards (PCBs) from our former Chinese electronics manufacturer. We did not really know what to expect from the boards, seeing as how the communication with the manufacturer had been such a big struggle. So even though we were excited to finally have the boards in our hands, we tried to keep our expectations low.

That is why Sten and Vincent dedicated the first day after receiving the boards to inspecting them. This included visual inspections and measurements with a multimeter to make sure that nothing had gone wrong during the board assembly.

Sten inspecting the main PCB.

The second day was dedicated to patching the boards. This means, for example, soldering very small wires between two points of the board in case a mistake was made in the design. 
To our surprise, the boards started working at the end of the second day!


FIRST ASSEMBLY

With working electronics at hand, we started to assemble the first kien speakers. That is, one subwoofer and one satellite.

The kien subwoofer consists of 7 plastic parts, 1 audio driver, 5 electronic boards, 4 wires, and 12 screws.

The kien satellite consists of 3 plastic parts, 3 audio drivers, 4 electronic boards, 4 wires, and 8 screws.

Last playing test before closing up the first kien subwoofer. It’s a GO!

TESTS AT QUANT

The following week we brought these working kien speakers to our electronics partner Quant for our first pre-certification tests. During these tests, we look at how much electromagnetic interference (EMI) the speakers are causing, and how the speakers are affecting other equipment (EMC).

Vincent in the test chamber, streaming to the Subwoofer over Bluetooth.

We put the speakers in a specialised test chamber used to block electromagnetic fields (a Faraday cage). Then we turn the speakers on and measure EMI in standby mode. Then we stream music over Bluetooth and measure again. Then we play over Wi-Fi, etc and we keep trying different features to see how much EMI they cause.

Vincent and Ard (from Quant) analysing the first measurements. If you look closely, you’ll see a red spike which is above the limit.

The frequencies of the spikes as seen in the picture above allow us to determine which component on the PCBs are responsible for the emissions. That is why these tests are very important for the certification process and will help Quant greatly during their redesign of our electronics.


That’s it for now, we will back very soon with a next update in which we will demonstrate a working 2.1 system.

Stay tuned and enjoy Ascension day!