Solid Hardwood, Engineered and Laminate Flooring - Underlayment for Re-engineering plank flooring

I just pulled up my carpet to install re-engineered plank flooring in an upstairs bedroom. The subfloor is 3/4 inch plywood. I noticed the 1/2 in. carpet padding was in very good shape. So, I asked myself the question, "why can't I used this as an underlayment?" I answered, "Because it will allow too much give in the wood flooring." Did I answer correctly? Could I make this work? It would surely make for quieter footsteps when someone is walking on it. I have it in another bedroom with the standard underlayment for wood floors and you can hear each footstep all through the house.

Thanks :confused:

Just to clarify what do you mean bey" re-engineered"? I'm not familar w/ this, do you mean pre-engineered, AKA pre-finished and only "real" wood on the top little bit? Just curious.
More importantly, I think your answer to yourself is correct. I think the padding would have too much give, and would feel very funny underfoot. More imprtantly, that allows alot for room for flexing and expanding; in fact it seems you be forcing flex whenever you walk on it, this couldn't be good for the floor in the long term.
I'm not an expert just a DIY-guy, maybe a "pro" has anotehr opinion.

You are so correct on the "pre-engineered." Thanks for the reply. I think we're correct.