Need some help from the experts on underlayment

[Diminishing Skills]

Hey everyone, looking for a bit of help from the experts on underlayment for hardwood floor install. Here is some of the basic information 1) new unfinished 2 1/4' Red Oak 2) Subfloor is 5/8" ply over 1x planks 3) half of the install is over a finished basement and half is over an unconditioned crawl space (so I will need some type of moisture barrier/retardant) 4) Will be a nail down application. 5) there is about 3/16" height difference between the floor I am installing and some preexisting hardwood floor (the existing hardwood is about 3/16' higher than the 'new' floor).

I've researched more than I care to admit, but looking for experience anyone has with any of the following 1) QuietWalk Plus 2) SoundStep LV 3) Aquabar B. I've used regular ol' #15 felt before and it worked just fine. I was thinking of trying something different to help with sound issues and a bit more insulation (but not even sure any of these actually work for sound attenuation).

Thanks in advance everyone. I really appreciate your help with this!

 

[highup]

Hey everyone, looking for a bit of help from the experts on underlayment for hardwood floor install. Here is some of the basic information 1) new unfinished 2 1/4' Red Oak 2) Subfloor is 5/8" ply over 1x planks 3) half of the install is over a finished basement and half is over an unconditioned crawl space (so I will need some type of moisture barrier/retardant) 4) Will be a nail down application. 5) there is about 3/16" height difference between the floor I am installing and some preexisting hardwood floor (the existing hardwood is about 3/16' higher than the 'new' floor).

I've researched more than I care to admit, but looking for experience anyone has with any of the following 1) QuietWalk Plus 2) SoundStep LV 3) Aquabar B. I've used regular ol' #15 felt before and it worked just fine. I was thinking of trying something different to help with sound issues and a bit more insulation (but not even sure any of these actually work for sound attenuation).

Thanks in advance everyone. I really appreciate your help with this!

I can't help much but you don't want anything thicker than the 15# felt. If you added any type of thicker foam or felt material you might increase the wood floor movement, creating squeeks.