Hello Engineers, Managers, Sourcing analysts, Purchasers and Quality control freaks!

Until now, I have went to two inspections concerning blankets and drinking bottles, and to one container loading supervision. This week, I went to a speaker factory to inspect subwoofers with our inspector. It was an FPI, a final product inspection, so all the products were ready. I thought it was time to go to inspect a bit more complicated products than fabric and plastic, so subwoofers sounded cool and interesting!

close look at pcb subwoofer speaker

What did we do then?

The speaker factory is located in Ningbo, which was nice – don’t need to wake up early in the morning for a train. Nevertheless, because of a massive Monday morning rush hour,  it took altogether around 2 hours to get to the factory.

This time, we didn’t need to check the workmanship so carefully, because the plastic of the cabinet came from another manufacturer. This company assembles the speakers and produces the actual woofer, so we paid special attention to the woofer and that the product actually works as it should – that you can hear the music. In other words, we checked the quality of the sound, as well as the power and connectivity. We also checked the quantity and packing details and evaluated the overview of the supplier, as we do for all products.

The QC Plan is the quality control checklist that is configured carefully for every inspection. The tests and measurements performed this time were so complicated for a normal mortal that I won’t be going through those so specifically. For me, I don’t even know the English definition for all the tests we did, so I didn’t even try to ask or understand what the factory workers were talking with our inspector.

The test that I understood was that we had to perform a life test for 5 speakers. We left them running music for four hours at the maximum voice to check that they still work well afterwards:

speaker sound test

We also checked the connections with USB, SD Card, Bluetooth, Microphone and Radio. Here the inspector is taking a picture to show that the bluetooth connection works:

inspecting bluetooth connection       I am taking a picture to show that the USB connection works: inspecting speaker   For other tests, they checked the voltage, AC power, frequency, channels etc.: electronics   After the inspection, we had time to go to the manufacturing room and see how they assemble the woofers: woofer

Complicated stuff!

After a whole day of testing sounds and music, I had a popular Chinese song playing in my head for the rest of the evening. Now, I also realize that it is really important to have a well-defined quality control checklist for each product. Before, when inspecting drinking bottles for example, the checklist was quite understandable even for a girl who is working in marketing. But for more complicated products, such as electronics, you definitely need to have a really specified, carefully compiled list and a qualified engineer in order to inspect the product successfully.


What was the result?

The inspection summery is as follows: 1. The factory had finished the products. 2. We have confirmed the products, and find the RMS power is not enough 3. We check the labels, and found that one logo had changed place. 4. We did every test as required except the “earth continuity”, because the factory said they had no applicable equipment for that.   More inspections coming out soon! – Katri Don’t forget our other blog about Sourcing at globalsourcingblog.org