EQ - FIR vs. IIR


Well-known member
Since my UMIK spoil liao, no more measurements for the time being, ... until I decide on the replacement.

Decided to spend some time on research. This time on the phase differences between FIR vs. IIR processing.

  1. Generate REW sweep WAV file.
  2. Run it through the 2 different EQ processing algorithm (MathAudio IIR, FIR convolution), then save the resulting WAV files.
  3. Convert the resulting WAV files to mono.
  4. Import the resulting WAV files into REW.
  5. Analyze.

Findings - big surprise from my expectation.
  • I expected FIR processing to be linear phase, but it wasn't
  • I expected IIR processing to have phase changes at the EQ points, yes this happened.

Here's the compare chart:


Hmm ... I wonder if I made some mistake with the FIR impulse wave generation?