Are coaxial speakers and midrange speakers the same? Nope, not at all.
Coaxial speakers are basically what comes stock standard in a car off the manufacturing belt – which means that they can produce a full range of sound. Basically, they are two speakers that share the same central axis and contain more than one driver, which allows them to produce a variety of sounds and frequencies.
Mid-range speakers are usually cone shaped and are part of what is known as component speakers. Usually installed in conjunction with woofers, tweeters and other speakers, they’re designed to produce a superior sound quality and are more customizable than coaxial speakers.
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PwrRngr
Squeak
Coaxial speakers are two speakers that share the same central axis, hence the name. What bad venge said is pretty much correct with the exception of 6×9 coax (because 6×9’s aren’t really midrange drivers). From what you’re said, I would buy some 4″ or 5.25″ component speakers. Then install those and replace your current tweaters w/ the ones from the components. That should give you more mids, but you’re still going to have overpowering bass w/ two 10s and 6x9s (both are bass drivers).