Question regarding improving vehicle audio

Rarely post so I apologize if I have gone about posting a topic the wrong way.
I have a 2018 tundra double cab non jbl sound system. Looking for advice and suggestions on how to obtain the best possible quality sound from an aftermarket head unit and aftermarket coaxial speakers without installing an aftermarket amp. I replaced the head unit a few years ago with an

$295 alpine ilx w650 7" double DIN touchscreen digital multimedia receiver with bluetooth, apple carplay and android auto

alpine ilx w650 and now want to replace the factory speakers but I am not interested in adding an aftermarket amp or a subwoofer. My plan was to replace all the current speakers with good quality coaxial speakers and just disconnect the existing tweeters. That said, I am confused about what I have been reading regarding replacing the speakers and the possibility of the sound being worse because of something to do with the factory amp. Is what I’m wanting to do with replacing all the current speakers with good quality coaxial speakers and disconnect the existing tweeters going to be realistic or a waste of time. Thanks for any feedback.

 

So yes replace the factory speakers, it will only improve the sound. The stock amp under the seat is pretty crappy. I went the other route, replaced the amp under the seat with Kicker amp with EQ, replaced all door speakers, replaced dash corner tweeters. My understanding is the dash tweeters are fed from the head unit and the doors are fed from the amp.. I assume the sound improved after replacing the head unit?

 

Send James Randy Taylor a FB message. I don't think you would find anyone nicer or more knowledgeable than he is about audio and tundras.

 

Main problem with the speakers/amp is that they're optimized for one another, replacing one means replacing the other. Like @agrestic1 said, the factory radio powers the dash speakers. Door speakers get powered off the amp under passenger seat. The door speakers are 35w @ 2 ohms, meaning the factory amp does about 20w @ 4 ohms. Most aftermarket speakers are going to be 4 ohms and usually start at around the 40w rms mark and go up from there. Since that's the case, if you swap in new speakers but keep the factory amp, you'll likely be underpowering the new speakers pretty significantly, hence the stuff you've read about new speakers sounding worse.

If you're interested in doing any of that, it's not terribly difficult if you're handy and you can put together a budget system of component speakers and replace the factory amp, all plug and play no cutting/splicing for under $500. Since you already have an aftermarket head unit you'd have good clean signal for an amp, and a little 4 channel amp would easily fit under the seat where the factory amp goes.

 

Another rec for James Randy Taylor. I installed his system in my 2017 and it is amazing! He was also helpful when I hit a snag installing.