With a sonorant second consonant, w

With a sonorant second consonant, we observe tone carry-forward from first consonant:
สนุก /saL nookL/ - Second consonant of cluster is sonorant, so the Low tone of this syllable determined by high-class consonant ส

With non-sonorant second consonat, there is no tone carry-forward and the second consonant prevails:
แสดง /saL daaengM/ - Second consonant of cluster is non-sonorant (mid-class)
เกษียณ /gaL siianR/ - Second consonant of cluster is non-sonrant (high-class)
เฉพาะ /chaL phawH/ - Second consonant of cluster is non-sonorant (low-class)