Task

To enhance the sound output level and sound quality of a tablet device using DSP means only.

Challanges

• As there was no direct way to inject test signals, we had to devise a scheme where test files were played on the device and then re-synchronized to extract the frequency response plot.

How we helped

• Measured the frequency response of the tablet in an anechoic chamber.
• Derived a correction equalization filter from the measurements using our custom MATLAB code.
• Provided advice to the client on the acoustical design of their next-generation tablet, including miniature loudspeaker part selection, location, and size of the loudspeaker cavities.

Results

We significantly improved the sound quality and speech intelligibility of the client’s tablet device in a cost-effective way by inserting a carefully designed equalization filter into their audio signal chain. This required no physical modifications to the device, only a software update.