0
$\begingroup$

I would like to implement in software the same isolators that the Pioneer EFX-500 features:

enter image description here

The manual says the following about the isolators:

High-performance 3-band Isolator Function [Fourth-order filter (–24 dB/ oct.)] Level control is possible between +6 dB to –inf. and a separation of up to –24 dB/oct. for each band ensure accurate sound reproduction.

The thing is, I can program in C# or C++ but I have no experience at all in audio processing so I am a bit at a loss on how to get started.

I have found the winfilter software which can generate C code I can reuse but I am not sure about what settings to choose:

enter image description here

Based on the specifications I've put above, can you suggest which settings should be used ?

$\endgroup$
0
$\begingroup$

After experimenting with winfilter, generating the following filters mimics the EFX isolators, amazingly :)

  • 2 * Butterworth LP 2nd order @ 300Hz
  • 2 * Butterworth BP 2nd order @ 300Hz/6000Hz
  • 2 * Butterworth HP 2nd order @ 6000Hz

So each signal passes through two filters of the same type, for some reasons I don't know the cause of, a 4th order BP in winfilter simply doesn't work and produces garbage instead.

As a reference, here's what really helped me out in matching the filters properties, white noise recorded for each of the bands then guesses until it matches:

enter image description here

Surprisingly, I'd say the above filters match the EFX about 99%, the only differences are at the edges where the winfilter ones really trim down the frequencies much more.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.