Right
昏 supplies the sound hūn exactly and packs in the original meaning: ancient weddings were held at dusk (
昏) when the groom went to fetch the bride. So
婚 reads literally as 'the woman-ceremony at twilight'. Sound-plus-semantic — not a pure phonetic loan.
昏 itself is
氏 lowering above
日 sun, picturing the sun dropping past the horizon.