Is it possible to create new calibration sequences in SoundCheck?
While calibration sequences can be run from the calibration editor, what if you run into a situation where you need a calibration sequence to do something slightly different than what it is designed to do? For example, equalizing a subwoofer. If you attempted to do this with the default Speaker Equalization sequence you would find that the sub cannot reproduce the initial 1kHz tone used to calculate sensitivity and the sequence would abort.
Before you begin modifying any calibration sequences please be aware that these sequences have been designed with failsafes to prevent equipment from being damaged. By going forward with any modifications to these sequences you acknowledge that you are aware of the risks involved and need to take caution with any edits.
In order to edit the EQ sequence so that it can be used with a subwoofer, open it from the File menu like a regular sequence. Calibration sequences can be found in the default SoundCheck folder:"C:\SoundCheck xx.x\Sequences\Calibration\". Even though you will be editing this sequence like a standard sequence, you should NOT run it as a stand alone sequence. Rather, you must run it from the Calibration editor like any other calibration sequence otherwise the signal path assignments will not be re-linked properly and you will run the risk of damaging your equipment.
Open the sequence “Speaker Equalization” and then immediately Save As with a different name (e.g. Speaker Equalization Subwoofer) in the same calibration folder it was opened from. The default sequence is a protected Read Only file so you won’t be able to overwrite it.
To edit the sequence, start at Step 3: “Test Level”. This is the step that creates the 1 kHz tone used to calculate the sensitivity of the entire output Signal Path. Edit the Stop (Hz) Frequency value as shown in the screenshot below. 100Hz was selected because it should be in the passband of most subwoofers but if your subwoofers response does not extend this high, a lower value should be used.
How your stimulus step should look in the edited sequence
For the next edit, open Step 7: “Test for Signal”. This step looks at the level of one frequency point on the curve created by step 5 and will let the test continue if the sensitivity level exceeds the limit at that frequency. Begin by changing the Limit’s frequency point to 100Hz so that it matches the stimulus frequency. Next, change the threshold of the limit step to 0dB.
For the next edit, open Step 16 which is a post processing step responsible for finding the sensitivity of the calibration tone. In the default equalization sequence the single value search range is 1kHz, but it will need to be changed to 100Hz (or whatever value you’ve selected for the stimulus) due to the edits you’ve already made.
The final edits are to limit steps 25 & 34.
These steps apply limits to the unequalized response (+/- 20dB) and equalized response (+/- 3dB) respectively. When editing these two Limits steps, only change the frequency values used in the upper and lower limits so they reflect the frequency range you will be using for the equalization. Edits to step 25 are shown below: