Back in my 20s, I had a Chevy Camaro with couple of Pioneer 6x9 speakers mounted in the package shelf. Since they were mounted in the openings in the package shelf (which acted as a baffle), the trunk acted as their enclosure and they produced pretty decent bass. Some of my friends had the similar speakers just sitting on top of the package shelf, and they could not produce any decent lower frequency sound, regardless of how they adjusted they 10 band graphic equalizer.
Sound quality and fidelity is very much in the ears (or actually the brain) of the beholder, but if the speaker cannot produce enough of low frequency sounds (due to lack of proper enclosure), equalizer will not magically bring up the bass sounds when the speaker is incapable of producing them. However the important thing is that you find the sound satisfactory.