If you're looking to upgrade the audio system in your 2008 Chevy Cobalt, you might be wondering what size speakers are factory installed. The good news is that the Cobalt comes with fairly large speakers from the factory. The front doors each have 6-1/2 speakers, while the rear deck has 4x6 speakers. These are all standard sizes that will fit most aftermarket speaker replacements.
If you're looking for an upgrade over the stock speakers, there are many options available that will fit into the existing speaker locations. Many companies make 6-1/2 or even 7 replacement speakers that will bolt right in place of the factory ones. If you want to go even bigger, you can install component speaker sets that come with separate woofers and tweeters. These can provide a significant improvement in sound quality, but they do require some extra work to install.
No matter what size or type of speaker you choose to install in your Cobalt, be sure to match the impedance (measured in ohms) and power handling capabilities (measured in watts). This information can be found on the Specs page of most aftermarket speaker manufacturers' websites. Choosing a speaker with too low of an impedance or not enough power handling can damage your amplifier or receiver.