Hi all,
I need some project guidance how to implement an equalizer using Teensy. As a preface I am not an audio expert, so my apologies in advance. My project reads audio through the ADC and passes the audio through to an external speaker, but I need the ability to manually tune and gain up specific frequencies. I am aware that the STGL5000 stereo codec has a 5-band EQ, but I need much more than 5 bands. I looked around and only need "graphic" equalizers, which provide a DC response for specific frequency bands. I do not need this, instead I am wondering if it is possible to add a gain to specific frequencies or manipulate the signal to make certain frequencies more prominent. This would need to happen quickly and process it in real-time.
The frequency range I am using is between 100-700 Hz. I am curious if I need to use a dedicated DSP chip which can be controlled from the Teensy's processor to achieve this or can it be done through FIR filtering.
Finite Impulse Response filters take the FFT of the signal and multiply a filter (such as a band pass) to preform a convolution of the signal. This result is then converted back to the time domain using an IFFT, then the output as a filtered signal.
The structure of this project is to mimic how a hearing aid works. I assume that modern hearing aids use a DSP and FIR filtering to achieve gaining up frequencies that the hear loses (17-20 kHz). Can anyone shed some light on how this is done and is Teensy capable of achieving this?
-NB
I need some project guidance how to implement an equalizer using Teensy. As a preface I am not an audio expert, so my apologies in advance. My project reads audio through the ADC and passes the audio through to an external speaker, but I need the ability to manually tune and gain up specific frequencies. I am aware that the STGL5000 stereo codec has a 5-band EQ, but I need much more than 5 bands. I looked around and only need "graphic" equalizers, which provide a DC response for specific frequency bands. I do not need this, instead I am wondering if it is possible to add a gain to specific frequencies or manipulate the signal to make certain frequencies more prominent. This would need to happen quickly and process it in real-time.
The frequency range I am using is between 100-700 Hz. I am curious if I need to use a dedicated DSP chip which can be controlled from the Teensy's processor to achieve this or can it be done through FIR filtering.
Finite Impulse Response filters take the FFT of the signal and multiply a filter (such as a band pass) to preform a convolution of the signal. This result is then converted back to the time domain using an IFFT, then the output as a filtered signal.
The structure of this project is to mimic how a hearing aid works. I assume that modern hearing aids use a DSP and FIR filtering to achieve gaining up frequencies that the hear loses (17-20 kHz). Can anyone shed some light on how this is done and is Teensy capable of achieving this?
-NB