It's pretty hard to pin this down firmly since attested pronunciations range wider than you seem to think, but based on what you've said in this thread, it seems like a good idea to sanity-check on the voiced/unvoiced distinction.

In the following clips, [1] has voice, [2] has unvoiced: [1]: https://audio00.forvo.com/audios/mp3/3/k/3k_9459069_74_57198... [2]: https://audio00.forvo.com/audios/mp3/s/x/sx_9001968_74_57198...