VelouriaL, you are just "reducing" the vowel in the final syllable to something called "schwa", which is sort of a default, central vowel that sounds like "uh". That is a common process in English. Since the word is unfamiliar to most, most people have to take a guess as to which syllable takes primary stress.
I think it''s the final syllable, so that it sounds like spin-ELLE, rather than SPIN-uhl. But that could be just me.
Now, here''s another brain teaser for me. How do you pronounce corundum?
Hmm. Checked a couple of online dictionary sites and waded through their transcription symbols. Then I found these. So it looks like SPIN-elle and kuh-RUN-duhm.
Someone has studies linguistics... I was more into etymology, more specifically, onomastics than-- what would it be-- morphology (?) when I took linguistics classes as an undergrad...
I think, according to your audio samples and final transcriptions, I say both correctly (or at least in standard American English...) except I give almost equal weight to both syllables in spinel.