Presently I have a Denon AVR-1806 with 6.1 speakers provided by Mission with a matching 10 inch sub. My fronts are mounted on the wall and my rears are on stands right behind my couch. System sounds great and very pleased, however I am at a point where I want to replace the old carpet with laminate flooring. I would like to know what difference I may notice or need to be aware of when switching from carpet to laminate in terms of sound quality? Any negative sound reproduction I might get out of it, or even positive. Would installing an underlayment with soundproofing help at all??
It is very likely that the sound will be much "brighter" if you replace your flooring. If you have a room in your house that already has the type of flooring you plan to put in simply go in and start talking (or have someone else do so) and listen carefully. Compare that sound with your current listening room and you should get some idea how the acoustics will change.
Soundproofing underneath the laminate wouldn't help, in fact one might argue that it would make matters somewhat worse assuming that the change is negative. Hey, who knows, you might actually like the change!