Sound proofing floor

Here is the link.
Green Glue

Green glue appears to be the most commonly used adhesive in soundproofing projects. A friend has a Rives-designed dedicated room which used a lot of that stuff.

As someone has already intimated.....is consult with an Acoustic Engineer (not some builder who has done acoustic work).
Acoustics is a science (unless we try to design a Concert Hall where it becomes more of an art), and what may seem logical to the uninformed can often be disastrous.
Putting in another floor is a pricey exercise and you want to do it ONCE and CORRECTLY.

Most of the advice posted above would spend your money for little result.
Sound travels in 2 basic ways....STRUCTURE BOURNE and AIR-BOURNE.
The trick is....the air-borne can become structure-borne and vice-versa.
Unless you TOTALLY decouple your new floor from the old, the STRUCTURE-BORNE sound will travel through.
Only an Acoustic Engineer can visit your situation and advise on the possible solutions.

I concur entirely with getting consul from an acoustical engineer, I needed to hear that from members, thank you.