Creating a Five Channel Surround Impulse Response

The stages outlined below should be followed when you want to create a discrete five channel surround impulse response.

  1. Stage 1: Microphone and Speaker Setup

    The first thing you’ll want to do is set up your speakers and microphones. Imagine you’ve decided to use the virtual listener approach—which requires five speakers and at least one microphone in the middle—which can be turned toward each speaker in turn. Ideally, you will have five identical, powered monitors. This will save you time when recording audio, and will allow you to see all speakers at once, to ensure they are each the same distance from the corners and walls, and so on. When all speakers have been positioned, you need to set up your microphone in the middle of the hall. Make sure everything is properly connected to your audio interface.

  2. Stage 2: Creating a New Project

    The next step is to open Impulse Response Utility and create a new five channel impulse response project. The New Impulse Response Project dialog informs you that this format requires five speaker positions and five mic positions. When you exit the dialog, 25 audio tracks will appear in the Inputs/Track section—one for each speaker position, from every microphone position.

  3. Stage 3: Configuring Impulse Response Utility Parameters

    Position your microphone toward the speaker you want to record (the left front speaker, for example). Set up the Monitor section, sweep generator, and input for the selected track.

  4. Stage 4: Recording

    Record-enable the selected track, and click the Sweep button. Impulse Response Utility will prompt you to name and save the new project after your first recording.

    Swivel the microphone to the second surround position, record-enable the track, and click the Sweep button. Once the recording has completed, the project will automatically be saved in the background. You may want to play back the track in the Editing area, just to double-check the recording.

    Repeat this process another 23 times, until you have recorded all 25 audio tracks needed to capture all possible microphone and speaker position combinations.

  5. Stage 5: Deconvolving

    Click the Deconvolve button after you have recorded (and checked) the audio files at each position. At this point, you should save the project.

  6. Stage 6: Editing and Auditioning

    If you have any unwanted silence at the beginning or end of your impulse response, use the Editing area to remove it. Use the Audition window to play some test material through your impulse response, to make sure that you’re satisfied with the result. If not, edit your impulse response further. If you still aren’t satisfied, go back to step 2 or 3, and start over.

  7. Stage 7: Creating a Space Designer Setting

    Once you are fully satisfied with your impulse response, you’re ready to click Create Space Designer Setting. Impulse Response Utility generates the .sdir and Space Designer settings files. Your new impulse response will be available the next time you open Space Designer.