Depending on the speaker layout settings and number of speakers, Dirac Live may not be able to select all supported speakers when creating the ART filter.
There is a maximum allowed number of "cross terms" which can be used. If this number is breached you would see a warning about it in Dirac Live, and have to de-select supporting speakers to reduce the number of used cross terms until you are within the allowed range.
Cross terms in Dirac ART refers to the specific calculations that coordinate how different speakers in a system interact to cancel out unwanted room resonances. They allow support speakers (any speaker capable of playing below 150 Hz) to actively neutralize unwanted resonances and reflection caused by a main speaker.
One cross term is allocated every time a speaker is selected to support another speaker. For example, if a speaker group in Dirac Live consist of four speakers, it will cost four cross terms.
The maximum number of available cross terms is DSP dependent (I.e its based on its computational capacity of the device). Dirac can not influence these numbers.
When an ART filer is calculated, Dirac Live will automatically choose the most appropriate speakers for support. This automatic selection should provide optimal ART performance.
If it would be preferred to select support speakers manually, deselect the checkbox and then re-select the desired speaker group.