Carpet Underlay/Padding

So i am looking to replace some of my underlay. The carpet has been washed but the padding still has a bit of funk to it.

What do you folks use as replacement? What should I be looking for? Dynamat is too pricey for me, and want to do it on a budget. I've saved my existing underlay as a trace pattern or worst case scenario to reuse (dont really want to). Any advice would be appreciated. Thanks.
Author: moreada