Final Year Project

I'd established that I wanted to do speaker design but I wanted my work to stand out from other people doing speaker design. Most importantly I wanted my loudspeakers to have a unique selling point. Not that I will ever sell them when they're finished!  After some research around different crossovers I stumbled across a company called MiniDSP. They specialise in relatively low cost digital signal processing hardware focused on audio processing. Their flagship device is a palm sized circuit board called the MiniSHARC, It allows the user to plug it in to their PC and program it to :

• Create a crossover network

• Time align the drivers

• Apply equalisation to each driver

• Apply equalisation to the overall systems response.

• Adjust the phase response independently from the amplitude response.

This last point is possibly the most exciting one as it is only really achievable with DSP. This allows the crossover to have steep slopes but maintain a linear phase response (in theory). A traditional analogue crossover, or even a 'normal' digital filter crossover introduce phase shifts to the signal (its how they work). This causes cancellations centred around the crossover frequency because the two drivers are playing the same frequencies but out of phase relative to each other. A linear phase filter works by adding a time delay to the signal (this allows all of the phase shifted components of the signal to be 'realigned' in time).

I had now decided that I wanted my project to focus on DSP, I titled it:

An evaluation of the use of digital signal processing within a loudspeaker design project.