What is cheapest way to improve sound quality of stock stereo?

I am sure this may have been covered here before but I am too lazy to search. I have the stock 6 CD changer (without JBL) in my double cab Taco. I'd prefer to keep the stock look with the head unit but I'd like to improve the sound quality. So what can I do to achieve this?

 

With that head unit the only options would be speakers or a subwoofer. You'll notice the biggest difference with the sub. I just did a h/u and speakers in my doors and the clarity is better but the bass actually got worse.

 

Yeah, that sounds about right. I powered my door speakers with an amp. Putting 6x9s in will also help with bass issues if you don't want to buy a sub.

 

I want to put a sub in does the stock head unit have rca jacks to connect a amp

 

I'm too lazy to search if this was suggested but the cheapest way to improve the sound of the stock HU is to set fire to it.

 

No, you have to get an adapter. I'm speaking about the single disc unit BTW.

 

I got a 40x4 Alpine amp and some really good speakers (MBs), sounds good up to volume level 30.

 

Ha Ha, that's funny

 

And it may or may not be true.