On my son's 1998 Blazer LS 4 Door 4WD he has factory tweeters in the dash, 6 1/2" speakers in the front doors and about the same size in the rear doors. (I have included pictures of the front & rear speakers). My question is : Does this mean that the original Delco HU has "built-in" crossovers because I want to replace all six speakers but am confused by the need to add external crossovers if I go with components. The tweeters are 4 ohm, the fronts are 4 ohm and the rears are 9.5 ohm by the way. I just want to get some sound in the vehicle - not looking for anything fancy but in the front 2 sets of 2-ways might be just as expensive as 1 set of components. I'd also like to keep the install as simple as possible so I didn't want to replace the HU or do any more wiring than I have to. Any suggestions/hints would be greatly appreciated.

 

It probably does not have a built in crossover. Most OEM speaker systems have a capacitor in line with the tweeter (majority right at the tweeter) to filter out the lower frequencies. This is called a passive crossover, it's quite simple to do, just get a value of capacitor to achieve the freq. you want. I can't recall the formula, but readily available by searching the net.

*EDIT*

If you really wanted to, you could use the caps that are on the factory tweeters to get the same sound from the aftermarkets. Although, if you buy a component set most come with passive crossover, so you would be set either way.

 

O.K., thanks midnight. That is good to know. Based on that info and my current budget I decided to go with speakers in the front & rear doors only for now and see how that sounds first. Thanks again.