KCM considers the following to be SUBDOMINANT (abv.: Sub) within the major scale:
2nd scale degree: Minor Subdominant
4th scale degree: Major Subdominant
..and thus share in the following properties:
-Repeated applications of the subdominant note will tend to want move away from that note in no specificed direction or fashion. Instead, if approached from a the left, they will want to resolve to teh left and vice versa (see this article) … absolute for 1 and 6; conditional on 3.
-The subdominants do not have a tritone as such since it is not within the octaves. As such, while it is part of the 13th chord structure (the required representation in KCM), it is neither “tense” nor “relaxed” but “ambigous” or “conditional” in that it’s push or pull to tonic or dominant is dependent on the other.
-The tonics have neither a “push to” nor “pull into” effect in that if a subdominant is established in gestalt memory, there will be no tendancy to resolve to it or against it… it is harmo-dynamically (link to definition and exposition) “neutral”..