Cavern QuickEQ setup guide

Before you start, please note that by default, all settings are set to the values that are correct in most cases. If you simply select your microphone with its configuration files and press Start, the results will most likely be the best you can get out of your system, and you just have to export it. Maybe you should try changing the target curve or doing a multi-mic measurement, but in most cases, the default is fine.

Controls


Use these buttons to start a measurement, interrupt an ongoing measurement, or exit QuickEQ.

Microphone

90° calibration


Open the microphone's 90° calibration file here. Calibration microphones should be pointed upwards and calibrated to sound coming from around it. If only this calibration is given, it will be used for all speakers, otherwise the curve will be interpolated with the 0° calibration.

0° calibration


Open the microphone's 0° calibration file here. This is the calibration for sounds that directly hit the microphone membrane (from the top center speaker if the microphone is rotated correctly). If only this calibration is given, it will be used for all speakers, otherwise the curve will be interpolated with the 90° calibration.

Microphone


Select your microphone here. The system should default to occasionally connected measurement microphones, but if you don't know if this is the case, make sure it's the active one by selecting your microphone here.

Setup

Settings related to the measaurement and correction target.

FFT size


The length of the measurement in samples. The longer the measurement, the more precise and less noisy it will be. Recommended sizes are:

  • 32768 - The minimal FFT size that supplies acceptable resolution for room correction. Only recommended for quick checks, as high frequencies can stilly be noisy.
  • 65536 - Default value. In low noise environments (basically in most home theaters and even living rooms) higher values won't make a difference.
  • 131072 - Compensation for high noise or low volume. If the measurement is still inconsistent, go higher.

Gain


Measurement signal volume relative to system output. The reference cinema level is -20 dB, home theater equipments are mostly using -30 dB. When the noise is low enough (two measurements after each other has the same result), this value doesn't matter, and choose the lower, don't damage your hearing.

Apply subsonic filtering


Remove low frequency signals from the speakers they are unable to reproduce efficiently. This can help protect the speaker, but might reduce audio quality.

Correct delays


Apply delays in the exported configurations to counteract different speaker distances and correct relative phases.

Used standard


Choose between DCI (Digital Cinema Initiatives) and Cavern channel gain standards. DCI dictates that all surround channels has to be set to -3 dB relative to the screen speakers, and subwoofers have to be amplified by 10 dB. Cavern mode is mainly used for upconverting movies to Cavern's format, putting an emphasis on surround sound, and gaming, as it doesn't apply -3 dB to the surrounds.

Target curve


Target curve to equalize the system to:

  • Flat - No additional EQ is applied, each frequency response is flattened as much as Target EQ resolution allows.
  • Room Curve - Frequently used home theater target curve with amplified lows and suppressed highs. A healthy mix of Depth and X-curve.
  • Punch - Adds an emphasis on the chest slam range with noticeable falloff so compatible effects rise to a higher amplitude in the same time span.
  • Depth - Adds a ramp to the subwoofer that keeps increasing the gain down to the end of the human hearing range. This can help increase the perceived low extension of the speaker.
  • X-curve - The standard cinema curve, nearly all movies were mixed to this target and all cinemas are configured to this curve. Greatly suppresses high frequencies.
  • Bandpass - Recommended for stage use, where the subwoofer level is changed all the time. This curve makes the transition to the subwoofers seamless at any volume difference if crossovers are not used. This curve is only applied to LFE channels.

Target EQ resolution


Determines how strongly the curves are smoothed and how many EQ bands will be used.

  • Low - Bands are 1/3 octaves from each other, LFE bands are 1/12 octaves from each other. Curves are smoothed to 1/3 octaves and LFE curves are smoothed to 1/12 octaves.
  • Var - Bands are 1/12 octaves from each other, LFE bands are 1/48 octaves from each other. Smoothing starts as the High option and ends as the Low option.
  • High - Bands are 1/12 octaves from each other, LFE bands are 1/48 octaves from each other. Curves are smoothed to 1/12 octaves and LFE curves are smoothed to 1/48 octaves.
  • Full - The EQ is completely adaptive, bands are inserted wherever they are needed, at each local minimum and maximum. Curves are smoothed to 1/12 octaves and LFE curves are smoothed to 1/48 octaves.

Experimental features


Features in this box are not considered accurate or require technical knowledge to double check the answers they provide. For example, the Correct polarities option might mess up systems close to 90-degree polarity, so impulses should be manually checked.

IR-filter

Impulse response filtering. For multi-mic measurements, this feature is not available.

Show impulse responses


Change the displayed graphs from frequency response to impulse response.

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.

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

Crossover


This is a debug interface to visualize how crossovers based on biquad filters behave. Their impact on the curve will not be exported as any crossover's spectrum distortion is measured and already corrected.

Multi-mic


Use the multi-microphone measurement feature to create a more uniform listening space, which means the experience of multiple seats are closer to each other. To add a position, start a normal measurement, and use one of the Add this result... buttons after:

  • Add this result to average - Used for every position except the reference detailed below. These results are only used for increasing the EQ precision.
  • Add this result as reference - Used for the reference position, which is the center seat in home theatres, and the center seat 2/3 of the way to the back in the cinema. Delays, gains, and polarities are calculated from the reference position.
After all positions were measured, press Calculate average, and the averaged result of multiple measurements will appear.