Cavern QuickEQ (Complex version) user guide
Impulse response filtering is used for making measurements more accurate in high noise environments or mitigating high distortion. The impulse response is the sound that would get to the microphone when an infinitely short, high power "clap" were sent through the system. This is calculated from the measurement signal, and not played to protect your equipment.
The impulse is one big spike with a decay on its right, that is your room's reverberation. Right windowing means you can cut this off from the measurement if you'd like to correct only the direct sound that gets to your ears first. Noise is also mostly present in this region, which you can also easily cut off with this setting. However, the more you cut, the more it will smooth the results, because windowing also throws away precision. Hence, right windowing is only recommended for very noisy environments.
To the left of the impulse, you can find sounds that were heard before they should have been, for example 2 kHz, when QuickEQ wanted to measure 1 kHz. This is called harmonic distortion, and in extreme cases, like when your microphone is overdriven, it can offset the resulting curves. Left windowing, which is cutting the left side of the impulse, is one way to fix it if the issue happens, but you should just decrease the measurement volume in this case.
Show impulse responses
Change the displayed graphs from frequency response to impulse response.
Show verbose measurements
Display both the frequency and impulse response for each channel on the same panel with extra informations such as low frequency extension, phase, and RT60.
Left IR window
If you enable this options, you can window out samples to the left of the largest impulse spike. Only noise and harmonic distortion is present in this region unless heavy processing is applied on the system, so you can usually safely cut most of this region.
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Right IR window
If you enable this options, you can window out samples to the right of the largest impulse spike. Reflections, low frequency details, and most noise are contained in this region, so expect a more precise but less detailed curve if you cut more samples.
Offset
Add an offset to the detected impulse peaks for fine adjustment over the impulse cut window.