Car Stereos: alpine car stereo, alpine car stereo, dual voice coil

Question
I have always had alpine in my vehicles and plan on putting one in my s10 blazer and was wondering if you could answer a few things.The blazer is four door and I plan on using the spr-13c for the rear doors and the spr-17c in the front doors with a mrp-f600 amp then add two subs but not sure witch to use with the mrp-m500 amp,the subs are the sws series subs(1043d or 1023d)since the amp can run 2 or 4 ohm subs.This is were I run into trouble witch is better 2 or 4 ohm in a sealed or ported box.This is not for comp or anything like that it is just for me.Some people say that I dont need to use a capacitor why is that and would it be a good idea or bad idea to use one.The blazer has a 105 amp alternator but would this be enough to handle the stereo.Any help would be great thanks.

Answer
Hi Edward,

Your Blazer should use the same size speakers for the front and rear; the rear doors use a 6-1/2" speaker, not a 5-1/4".  You can use the SPR-13C if you want, but you may need to build an adapter bracket to make it fit correctly.  Also, you should have spaces for speakers on your dash as well.  You might want to consider using the SPR-17S component set, and install the woofers in the doors and the tweeters up on the dash.  This would be more expensive and more work, though; especially since you'd probably need to build an adapter plate to fit the tweeters in the 4x6" dash locations.

As for the amplifier, there's not a big sound quality difference between 2-ohms and 4-ohms.  The main difference is that the amp can produce more power into a 2-ohm load than it can into a 4-ohm load.   The power produced by the amp will be divided between the two subs.  So, if you wire the subs for a 2-ohm load, then the amp can produce 500 watts RMS, and each sub will get 250 watts.  Since the subs are rated for 300 watts RMS maximum, 250 watts would be just about right for them.

Because the Type-S subs are a dual voice coil design, you'd need to buy the 2-ohm subs in order to combine them for a 2-ohm load at the amp.  (If they were single voice coil subs, it would be different--you'd need two 4-ohm subs to get a 2-ohm load).   To get a 2-ohm load with two of the SWS-1023D subwoofers, you'd wire them according to this diagram (found on JL Audio's support site):

http://mobile.jlaudio.com/graphics/Support/Tutorials/wiring_images/DVC_Series_2....

If you're just planning to use the system for normal music listening, I don't think you'll have any problem with the stock alternator.  

Capacitors are sometimes useful in car audio systems, but they don't usually make a noticeable difference with a subwoofer amplifier. A capacitor can store power, and quickly produce high current on demand; but the amount of power it can store is relatively small, and it discharges very quickly.  They can sometimes help the sound quality when used with 2-channel and 4-channel amps, hooked up to your front and rear speakers; but their benefits are less apparent with a subwoofer amp.   If you install one, it won't hurt anything, but it's not likely to help either (at least until you add a 4-channel amp for your door speakers).

Hope this helps!

Brian