The Dayton Audio PS65LP-4 6-1/2" high efficiency full-range driver could be the ultimate upgrade for your factory stereo system. Designed to be a simple drop in replacement for your stock speakers, this driver's amazing efficiency can increase the output by up to 10 dB without adding any additional amplification. Also, this is an excellent driver for use in any high efficiency full range speaker designs.
Aside from adding an amplified subwoofer you simply can’t make a better, more cost effective improvement to your factory car stereo than swapping out those mediocre factory speakers for the Dayton Audio PS65LP-4 ultra-efficient 6-1/2" drivers.
Today even the most basic factory audio systems have various other electronic components and systems integrated into the head unit, as a result less consumers are willing to replace the head unit. Not only could you lose certain features but in some cases may end up with electrical problems. Who wants to take out the head unit anyway!
Although the Dayton Audio PS65LP-4 (with 2-3/8" mounting depth, full-range capability, excellent off-axis response and exceptional efficiency) was purposely built for car audio, its parameters and design features serve it well for numerous other applications. Such as, but certainly not limited to: a full-range in-wall/on-wall/ceiling speaker system, a devoted midrange in a ultra-efficient three-way system, or as a great candidate for a folded horn or transmission line design for the class “A" amplifier guys.
The graph below illustrates how the typical bass and treble controls in most stock head units (i.e. center frequencies of 100 Hz and 10,000 Hz) can be used to dramatically flatten the response of the PS65LP-4.