I've got a Memphis PRD.1000 and 2 12" subwoofers in my car. It's a 2006 Dodge Charger and I still have the stock head unit and the stock speakers in it. The components are plenty loud enough for me and the amp seems to be working fine. So my question is will my audio system improve a lot if I get an after market headunit? Thanks.
You will get a little more output at the same amp gain settings which translates to slightly less noise overall, and the D/A converters will be of a higher quality. What some people don't realize is that in a noisy and far from ideal environment such as a car, it is very difficult to tell small differences in sound, such as a store-bought cd vs. a burned MP3 (128 or higher) or a (quality) factory deck vs. an aftermarket etc.