Basement subfloor?

We are finishing our basement and are unsure whether or not we need to put a subfloor in before carpeting? We plan to use a concrete sealer and are putting in an upgraded carpet pad. Any advice?

Hi carried, welcome to the forum Is there any reason you would have to put in a subfloor in your basement? I mean, humidity or anything like that?
If not, I think the measures (concrete sealer & upgraded carpet pad) would suffice.

Hi carried...
may I suggest you look into a kind of subfloor specifically developed for use in basements, under carpet? It is called ThermalDry. They are plastic, interlocking, floating tiles, specifically developed for basements.
They raise the padding and carpet off the floor, and thorough some channels in the back, they allow the concrete to breathe and moisture to evaporate, instead of soaking into the padding and carpet.
They are 100% waterproof too, so if you basement ever floods, they will not rot or grow mold like a wooden subfloor would.
Anyway, whatever you do, avoid using any materials made out of organic compounds in the basement floor, even if you basement doesn't leak.
Think that the floor is a slab of porous concrete buried into humid soil. Some level of moisture always seeps through.