Will sonapad is sufficient for sound proofing

Sonopan is a good sound-damping layer and can noticeably reduce noise, but by itself it isn’t considered full soundproofing. If the goal is meaningful sound isolation—like reducing voices or TV noise—it works best as part of a layered wall system with insulation and additional drywall. We can tailor the assembly depending on how much sound reduction you’re looking for.

It depends on the STC rating you are after. There are a lot of other assembly that can change the STC rating. One of the beneficial assembly that helps STC is adding metal resilent channel (reasonable cost) or doubling up the gypsum board but will result in higher cost. You can also look into the batt insulation rating as well as some are more dense and provide better sound control.

If you want to use it alone its better to put on walls but because people are walking, moving chairs right on the ceiling the noise will travel faster and you need to fill the joists with rockwool, then run Baileys channels 2'o/c then sonopanels and 2 layers of type X gypsum and that should exceed the 57 STC for the sound proofing

SonaPad (or similar isolation sheets) can help reduce sound transfer, but on its own it will not make a ceiling “soundproof.” There is a big difference between soundproofing and sound reduction. True soundproofing requires a full system approach: decoupling, insulation, mass, sealing of air gaps, and proper installation details. A single layer of acoustic pad with drywall will typically improve impact and airborne noise slightly, but you may still hear footsteps, voices, or bass frequencies from above. with over 16 years of experience in this space and the way our homes are built, its not possible to achieve complete sound isolation.