Do these help reduce noise versus doing speaker level directly to an amp or is it just converting the same dirty signal?

 

A signal is only as good as it's weakest link...

So simply, no, it won't be better.

 

Don't many converters have circuits to help reduce noise or is it just masking it? Looking for real-world experience with these.

 

Had a llc from these guys a few years back that worked great. Pricey though, but came highly recommended.

http://www.davidnavone.com/adaptor_products.htm

 

What is your setup? Are you only going to be pushing a sub?

 

I have an '06 EX sedan that I don't want to change the head unit on. I have Infinity kappa comp. to replace the fronts and a smaller MTX amp to run these. I will be using the Honda bass system in the back for ease of install (don't want a box). I bought a Scosche converter that has a noise reducer curcuit.