The Walmart near me is pretty meh...

I guess any decent speaker would beat 10 year old ones, even if they were great 10 years ago. They're still old.

Are there any specifics I have to watch out for?

 

Stay away from Sony. They make really bad speakers. As for spec, if your not adding an amp any speaker will work. But when you add an amp you have to pay attention to max watts.

 

What about size? What works best in our trucks?

 

6x9s in the front, 5-1/4 in the rear. I would look into "3-way" speakers to give you the best bang for your buck. I'm one of those who has a ear-blowing setup

 

What's the difference between a 3-way and a 2-way?

 

3 way are better than 2 eway, but 2 way would be minimum. It has to do with range. Not and audio expert, but replaced all 4 speakers in mine with 3 way recently to go with new Kenwood head unit. Sounds really good.

3 way are only slightly higher than 2 way. If a speaker dow not specify 2 or 3 way, stay away.

 

"The main features of a 3-Way speakers is that they have a tweeter to handle the high frequencies, a dedicated midrange driver to handle most of the vocals and instrumentals, and also it will have at least one woofer to handle the lower ranges."

stolen from google.

 

Keep in mind though, the infinity system has individual amps at each speaker. You would have to do some serious hoop-jumping to make them work with any new speakers you buy, and if you don't use them, you will probably want to have a look at some medium power amp as well.

 

When I put my kickers in the front door, I just cut the old speaker wires off the speaker and hooked them to the new one, leaving the amp, and the tweeters in the a-pillars. They sound pretty kickin'.

 

Best option be to get some new speakers and a new amp? Get rid of the whole infinity system completely?