Any drivers from CDT can be purchased al a carte, as in without crossovers. I don't sell Hertz so I don't know what a Hertz dealer could offer. If you're comparing speakers from similar ranges you'll get good sound from either brand. They won't have the same sound but you wouldn't know the difference unless you installed one comparable set from each brand in your vehicle. Good speakers are helped a huge amount by how much effort you put into the installation and how well you tune it.