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Equalizer APO Configuration

Shanon Pearce edited this page Jan 10, 2023 · 44 revisions

This impulse response dataset can be used with Equalizer APO, an Audio Processing Object (APO) for Windows featuring convolution capabilities. Instructions on how to configure Equalizer APO to use the impulse responses for headphone correction and room simulation are provided below.

Installation steps

  1. Download Equalizer APO.
  2. Follow the Equalizer APO installation tutorial.
  3. Download the latest release of the ASH-IR Dataset and extract the ASH-IR-Dataset folder to the location of your choice. Alternatively, clone the GitHub repository to your computer.

Configuration steps

  1. In the configuration editor, add a Preamp to your config.txt file to reduce any clipping that may result from the convolution. The dB value required varies depending on the speaker configuration and filters selected. The analysis panel may be used to identify potential clipping. Alternatively, the Peace interface may be used to adjust pre-amplification as it offers automatic clipping prevention.
  2. Add a new Include control to your config.txt file, then navigate to the E-APO_Configs folder and select a BRIR convolution configuration file for binaural room simulation. A set of BRIR convolution configuration files have been included in the dataset for each room and for a range of common speaker configurations.
  3. Add a new convolution command to your config.txt file, then navigate to the HpCFs folder and select the desired HpCF WAV file for headphone correction. Refer to the HpCF page for more information.
  4. A compatibility filter will also be required if you are using in-ear or on-ear headphones with the BRIRs. In this case, add a new convolution command, then navigate to the Compatibility_Filters folder and select the WAV file for your headphone type. A compatibility filter is not required for circumaural (over-ear) headphones.
  5. Alternatively for steps 3 and 4, include a HpCF convolution template and modify it by selecting the desired HpCF WAV file.
  6. Set your sound device's default format to 44100Hz under the properties of your playback device. In Windows 10 this setting can be found in Settings -> System -> Sound -> Sound control panel or Settings -> System -> Sound -> Device properties.

Sample config.txt in the configuration editor: Sample config.txt in the configuration editor

Troubleshooting

  • The BRIRs and HpCFs have been sampled at 44100Hz so the sample rate of the playback device must be set to 44100Hz. The sample rate of the device must match the sample rate of the file.

  • If your audio device does not support a 7.1 surround channel configuration, a virtual audio device such as VB-Audio Virtual Cable or Voicemeeter can be used for audio processing in place of your regular audio playback device. Equalizer APO can be installed on the virtual audio device which can be configured for 7.1 audio, and the output of the virtual audio device can be sent to your regular audio playback device.

  • Ensure that the BRIRs are at the correct relative path. The 'E-APO_Configs' folder and the 'BRIRs' folder must be located in the same folder for the files to be read by the E-APO configurations.

  • The convolution, pre-amplification, and include commands can be placed in any order.

  • To assist with pre-amplification, the table below lists the approximate gains that the various IRs in the dataset apply to the low frequencies, which is the region where clipping is most likely to occur.

IR Approximate gain
BRIRs (2.0 configuration) +18dB
BRIRs (5.1 configuration) +27dB
BRIRs (7.1 configuration with 2.0 audio stream) +18dB
BRIRs (7.1 configuration with 7.1 audio stream) +31dB
HpCFs -6dB
In-ear headphones compatibility filter -4dB
On-ear headphones compatibility filter -2dB
Improved Diffuse-Field EQ filter 0dB