advanced audio recording
A testsignal generator for audio applications in an FPGA

Test Signal Unit

This module uses additive sound synthesis by superimposing several sine waves, matching the intended generator frequency. The principle corresponds to the Fourier analysis and LaplaceTransformation, according to which it is possible to generate nearly any waveform imaginable from simple sine waves.

The first module was used in an industrial application to generate waveforms for super sonic waves in parallel.See the page here: Additive Frequency Synthesis

Here I am using it as a LaPlace waveform generator to generate band-limited signals as test wave forms for audio circuits. Up to 31 waves can be generated.


Synchronization Unit for 44,1 kHz to 48kHz

 The module works up to 120 MHz and runs on a current Cyclone III FPGA.

Wave Synthesis

WAVE Synthesis Example Laplace
Complex Wave from super imposed sine waves

WAVE Synthesis Example Laplace
Complex Wave from super imposed sine waves, actually a band limited saw tooth

Dynamic Wave Table Synthesis

In a modified version, I am using 7 waves to create harmonics in order to build the desired music wave. Using several of these waves, a virtual wave table processing is possible by walking through these waves dynamically. See the new Wave Table Module and the old Wave Table Module

Read about the detailled function in this article Wave Synthesis


Full Synchronized

44,1 kHz

48 kHz

88,2 kHz

96 kHz
96 kHz
Audio DSP


© Sound of L.A. Music Productions 2008