I don't have my CKS77 with me at the moment but as you know the solid bass series earphones are known for their strong bass that goes very deep. I would say both are about equal in the sub bass region and how deep they go but it is the mid bass that is more manageable and grown up on the CKS1000.. The overall control of the sounds including bass is on a nice high end level on the CKS1000..If your wondering if something like the CKS1000 is worth the price increase over the older CKS77. Absolutely without a doubt in my mind it is worth the price increase.
These are not just a simple upgrade from the CKS77 it is on a different level of sound all together.. No worries about the bass end on the CKS1000. Everything on them are higher resolution including the bass. It has the better tuning over the older CKS earphones and has the newest version of their air chamber tech. Double dampening with double chambers= outstanding deep full sound.