Last week our engineers were working with the team in the factory in Poland to examine the welding process as well as to assemble a new batch of earplugs.  After each build the hardware is closer to the final stage, which allows us to measure the latest audio performance and conduct other testing (e.g., audio testing, charging testing and air-leak testing).

In this update, we’ll share with you the progress, what’s left to be done before the mass production and the estimation for delivery. Also, you’ll find in this update the progress and the items to be improved are grouped in sections.  There are only few areas that require fixes and each area has one or two small parts that need to be modified.

Ultrasonic welding

This is the method employed in our production line to get perfect welding of the components. By using this, we are able to make the devices super small, because they do not need any room for connective mechanics like screws.

As mentioned in the previous update, on tightly welded samples, the ultrasonic energy was too high for the elastomer to handle.

ResultThe welding rip in the plastic was changed as in the picture. The welding process now works perfectly with excellent quality. The process is airtight, durable and does not make any sharp edges.

Charging case and charging tester

 The charging case is fully ready for mass production.

In parallel to all other activities, we are also progressing with building automated test tools for manufacturing. Charging tester is one of those critical tools.

 Charging tester charges the batteries of the earplugs with the charging case. The tester measures how long it takes to charge the battery from flat to full. Based on that, the battery can be assessed if it is in good condition. A battery is generally good when it arrives from the manufacturer but if it is mishandled and short-circuited, its capacity and internal resistance will suffer. This tester will eliminate those samples. Other faults in the charging circuitry will be found too. As another bonus result of this process, batteries will be freshly charged when the products are shipped. This helps maximize the shelf life.

Result: The charging tester is progressing to the final stage. We are waiting for all the PCB to be shipped to complete the device. There will be tens of these testing devices for the automated charging testing process at the factory in mass production.

 Audio canal, air leak tester, and audio tester

 In the last batch of plastics received from the tool maker, improvements in the pressure relief channel have been shown, however it’s still not perfectly right for the optimal air leak. We decided to make some slight modifications for the molds that can be easier for the tool maker, yet the quality is still assured.

This is the latest design for the tool maker.  We’ll get the new plastics in two weeks. In the meantime, we have had the plastics modified manually based on the new design. The modified plastics have passed the tests and work well.

Air leak tester

Air leak tester works by creating a small vacuum into a container attached to the sound port of the earplug which is the tube that normally goes into a foam earplug and in your ear. Then it measures how fast the vacuum dissipates. This tester is used for two main cases:

  • Pressure relief channel has to be able to let air flow at a specific rate. Too high flow and it will reduce the speaker’s performance at bass frequencies. Too little flow and atmospheric air pressure variations can push the speaker membrane which may prevent operation. This is tested after the speaker and its gasket are installed but before closing the case completely.
  • Air seal of the enclosure is tested after the earplug’s case is welded ultrasonically. The welding has to be air tight as well as the gaskets sealing charging contacts and microphone.

We have conducted this test by our manually created tool at the lab. The automated machine has been made and is being shipped to the lab.

Audio tester is the most important tester and it has progressed the most. It will measure the frequency response of the device in silent mode and hearing mode. The noise floor of the electronics is also measured. Besides, the audio tester tests the function of sound level limiter, the Hall-effect sensor, and the button. The limiter works in the hearing mode preventing too loud sounds from entering your ear if you are in an area with loud noises. The Hall-effect sensor switches the device off when it is placed in the charging case.

This is one part of the audio tester which will be shipped to the factory for automated audio testing process in mass production.   

Audio tuning

As mentioned earlier, after each build the hardware is closer to its final stage, and more samples for better accuracy, which allows us to measure the latest audio performance. Based on the results, we fine-tune the properties of the filters that generate the active noise cancelling signal. It is important that the noise cancelling signal is generated at correct level and phase at all frequencies for the best noise cancelling effect. The hearing mode is also adjusted whenever necessary. We call this audio tuning.

Estimated schedule:

In W15, the next build for 200 devices will be implemented.

Mass production with the newest plastic parts set up in Poland’s factory is targeted to begin in W19.

The first 1000 units in mass production ramp up mode is planned to start in W20.

And the full speed manufacturing for thousands of units is estimated to begin in the first week of June.

In W16 and W17, we’ll conduct the analysis for those 200 devices and if everything is ready, the first devices can be shipped to the very first backers in small batches 😊

As in many innovations, the design process of QuietOn Sleep is non-linear, requiring many iterations along the way. However, we are coming closer to the final stage of product development. We do believe in this innovation and feel deeply responsible for the sound sleeps and quality rest and focus you will have in this bustling and hustling modern world.  

At the root of this belief is you, our backers, whose support has been the core of our motivation that have led us up to this point. We’re really excited to get you your QuietOn Sleep soon so you too can ultimately experience your own bubble of quietude.

Thank you again for all of your support, and for helping make QuietOn Sleep possible.

Best regards,

QuietOn Team


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