Welcome to another Kokoon update! This time we’re going to talk about progress with testing, our EEG system, audio development, our latest prototype, tooling progress, and some new hires we’ve made.
We have of course covered some of the testing taking place in previous updates but, as we progress to shipping, the amount of testing we’re doing will keep ramping up. It is of critical importance to us that we provide a high quality headphone, which will stand up to long term use.
To that end, we can share some of the ‘Lifetime testing’ we’ve been doing with our design. Please see the video below showing a headband testing cycle.Media error: Format(s) not supported or source(s) not found
Headband testing cycle
Since we have located our complex flexi PCB design in our headband, this has required a very advanced headband design (as we’ve detailed in a number of our previous updates!). It’s very important therefore that our headband will stand up to hard use and protect the internal electronics. After cycle testing our headband 2000 times we found no deformation but an approximate force reduction of 5%. We can use this information to adjust the design and ensure that we have an ideal force profile for the full lifetime of the product. We are testing next week with a magnesium alloy in order to compare results before making our final selection.
EEG configuration update:
Since Kokoon’s inception the team have hoped of being able to use an Ear-to-ear type EEG sensing configuration – for the obvious benefits to comfort, signal integrity and user experience. Back in 2015, an Ear-to-ear configuration wasn’t used, as there had been no direct experimental results confirming the channel would work for accurate sleep staging.
Kokoon’s current Ear-to-head EEG system was employed as it is a standard channel in PSG (polysomnography) type sleep scoring, however Kokoon has built the ability to measure Ear-to-ear EEG as well as Ear-to-head EEG into all of our prototypes to date. This was in the hope that with testing we might be able to get it to perform to requirements.
After recent in-house testing and further literature review, we have been able to confirm that Ear-to-ear configuration will achieve a far more reliable and accurate Sleep staging system. The EEG signal will be more reliable throughout the night and will be less sensitive to motion artefacts (which the head EEG sensor is particularly sensitive to). This advancement in design also allows for a simpler manufacturing process and a more robust system, able to better withstand long term use.
The Kokoon team are thrilled with this development. In addition to the benefits mentioned above, there are significant positives for the user experience. The headphones will be easier to use and will also be more comfortable
The audio development has focused on getting a reliable audio seal. A reliable audio seal is critical as any air leakage will have a negative effect on the acoustic response (especially bass) of the headphone. As the Kokoon headphones also feature ANC functionality, it is doubly important to get a consistent bass response, as the ANC filter circuit is designed to match it. As you can see below, we have been trialling some off the shelf cushions (for basic testing/benchmarking).
We found our previous design, shown in past updates, wasn’t performing quite to the standard we need, so we’ve been conducting our latest tests with different materials and we’re happy to say we’re now getting great results. We started with off-the-shelf cushions, as pictured below, and we’re now working with our own bespoke design.
An off the shelf cushion in our headphones – rather large – ours are much smaller
Our own bespoke design!!
Our cushion designer has finished the design we need and we’ve built it into our latest sample (see above). Below you can see our supplier’s engineer building up the CAD for the cushion
Hard at work in China
We have also been trialing better transducers. Like the audio seal, a reliable and high quality transducer is important to achieve a consistent response. We can see that using a transducer with a PEEK diaphragm brings performance improvement (flatter response than that of a PC (polycarbonate) transducer).
All the above developments have been built into our latest sample. You can see some images below (apologies for the poor quality. We really aren’t photographers
Latest sample on a stand
In the image below you can see the underside of the headband without the head sensor – a much cleaner design. You can also see the current audio seal we are testing. Fit and finish is not perfect yet as this area of the sample is still being tested. You can hopefully see greatly improved finishing around the headband endcaps and buttons. Still a little work to get it perfect, but we’re very happy with this result. Please note, as you can see, the ear cushions do not have the layer of foam and fabric on them in these images, to allow you to see the air channels
The tooling process started earlier this week when we sent out our first CAD, to commence the quotation and DfM process. The tooling process will be time consuming, we have over 40 parts that need to be made, which will allow for the rapid and reliable manufacture of our parts. Once we select our preferred supplier(s) we will be sharing some great updates from that process and also understand a more detailed schedule from the toolers and if this has any impact on our predicted delivery.
We are thrilled to be welcoming a new mechanical engineer, Andrew, to our team from the start of March. Andrew joins us with many years of Product Design experience and a deep understanding of design for manufacture and the process of moving a design to a factory and delivering the tweaks necessary to get a production line operating efficiently.
Andrew will be spending time out in China with Manon and the rest of the team, working with our factory partners over the coming weeks and will be instrumental in ensuring that what comes off our factory line performs to standard. Welcome Andrew!
That’s all for now. We just want to thank you again for your patience and support with our development. As always, we love hearing from you either though email, our website www.kokoon.io or through our social media channels Facebook, Twitter and Instagram.