The rule determining pronunciation of " sprawdź " in the Polish language

I am a native English speaker trying to learn Polish. When I hear " sprawdź " pronounced, it sounds like the "w" is like an "f" and the "dź" is like a "ch". But pronunciation guides say "w" is pronounced like "v" except before voiceless consonants, where it may be pronounced as "f". But the guides say "dź" is somewhat similar to the "g" in "gene" which to me is a voiced consonant. What is the rule determining pronunciation of " sprawdź " ? Thank you!

@mhurwicz

in final position dź sounds like ć (which causes the w to be pronounced like f).

all consonants with voiceless equivalents (b, d, g, dż, dź etc) are devoiced in final position (are pronounced like p, t, k, cz, ć etc)

in connected speech they aren't devoiced if the next words begins with a voiced consonant.

there's also a kind of spelling pronunciation where the the voicing might be retained but this is used only in isolation (or to let someone know how the word is written).

don't worry too much about voicing assimilation yet, a lot of it comes naturally once you know the basic principle

Palatalization in Polish can indeed be challenging, as that final "z + mnaki znak" almost seems to disappear if pronounced by a Polish
native speaker. A challenge for me was "przyjazn". Must have repeated it as many as fifty times before my native-born teacher finally gave
it her seal of approval:-)