Going active?

[Masta GimP 10+ year member]

OK guys...Here's the deal. I'm getting back into car audio thanks to a new job (@ Circuit City //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif ). I was looking at getting the Kicker 8" SS midbass and the SS 30mm tweeter too. Now I would get some type of 3-4" speaker too, that i haven't decided. My main questions is would i have to get a crossover like this ( http://www.cardomain.com/item/KIC03KX3 ) or what? That's where the whole going active thing confuses me. If that's not what I need, any recommendations or help would be greatly appreciated!

*Edit* and any recommendations for a 3-4" midrange would be lovely too

-Mark

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[thch 10+ year member]

there are 2 types of "3 way crossover". there are the more common "front - rear - sub" type which has a highpass filter for front and rear, and a lowpass for the woofer. not too useful, given most HU's and amps have the same features.

then there are real 3 way crossovers. these have a highpass for the tweeters, some lowpass/highpass combination for the mids, and a lowpass for the subs.

but when you look at what you want, you end up with a 4 way setup -- you need:

tweeters -- highpass (2000-4000hz)

mids -- lowpass (250hz+) and highpass (2000-4000hz)

midbass -- lowpass (250hz or so) and highpass (50hz or so)

subwoofer -- lowpass (50hz or so).

so you should look at how you can get the correct signals to the correct amps. which is the next point -- for active 4 way setup you will need 7+ channels.

for this reason, people will sometimes run the mid and tweeter with a passive crossover. doing this removed the need for 2 channels.

for signal processing, you may be able to use some of the filters on the HU and the amplifiers. for instance if you use an alpine HU that has the 3-way mode, you can set the "sub" crossover to 250hz lowpass. this signal can then go to the amps for the midbass and subwoofer. the midbass's amp can apply a highpass @ 50hz. the subwoofer amp can apply a lowpass @ 50hz. in this case, no extra processing unit is needed because the HU has performed the crossover for the tweeter and midrange and part of the midbass, leaving the amps to do the rest of the filtering on the midbass and the subwoofer.