DSP Audio Effects Project

1.) The five audio effects we have decided to implement are reverb, compression (non-linear), equilization, distortion (non-linear), and tremolo. We have completed our own implementations of compression, equilization, and reverb, which we will compare to implementations we found from other sources. One difficulty we encountered was in trying to implement a pitch change algorithm. In the next week, we plan to implement our own version of tremolo to compare with an approach we found online. Additionally, we will create the output audio files that will go on the website. 

 

2.) Some of the DSP tools from class that we are using are filtering and linearity. For example, in the equalizer effect, we utilize a lowpass, highpass, and bandpass filter and add emphasis to the frequencies in that region. In the reverb effect, we used a sum of shifted and scaled signals to create and echo type sound that can be changed to simulate different rooms.

 

3.)Two of our effects apply non linear systems to our audio samples, those being distortion and dynamic range compression. Compression looks at power levels above a certain threshold then applies the desired ratio to portions of the signal above that threshold to adjust volume levels across the signal and make them more uniform. Distortion increases the intensity of frequencies not heard in the original signal. These frequencies are the higher harmonics of the fundamental tone and need to have a non linear gain because higher frequencies are more audible.

 

4.)Applying the effects to the recordings we have and just seeing how they change the song’s sound as well as just messing around with some of our favorite songs and hearing the result of the effects we’ve made.