New Kiseki blackheart cartridge not sounding right.

Try all the excessive sibilance troubleshooting recommendations. If that fails, time to have it looked at by a shop, or someone who makes house calls.

I have a Blue and have been curious about the Blackheart That's a $4K cart-it better sound like one!

"cantilever and stylus are so far underneath the body it makes trying set the overhang and horizontal tracking angle almost impossible. You just can’t see"

Looks to be the same arrangement as the PH/Blue.

I have terrible vision. A good light and magnification is all that's needed, along with patience. Adding .5 or so tracking force may help.