EQ vs Crossover

Usually an EQ can do more bad things to your system then good if you dont know how to use them. If you're a proffesional you can like forbidden said use them as a tool to help but i really wouldnt suggest one unless you thing you really have a problem. If so then try looking at Zapco. Probobly make some of the best EQs and proccessors around. Here's the link: http://www.zapco.com/nosound/index3.html

If you need a crossover, get a crossover.  If you need an EQ, get an EQ.  Like stated above, don't add components into your signal path unless you need them, and then get components designed for the job you need done.

Boost/Cut refers to an EQ's function of increasing or decreasing signal strength at specific frequencies.  "Q factor" is (very generally) related to efficiency.  Higher Q generally means higher efficiency.  In an equalizer, the Q factor generally refers to the bandwidth of each adjustment band.

First of all thanks for the answers,

I am not quite sure why you all asked why do I think I need a eq or xover. I always thought that when you are using more than one amp that a electronic crossover is a good source to divide the signal. I am planning on installing three amps. One for sub, one for midrange, and for the highs. I am confused by the things you all stated. I would appreciate it if anyone of you could explain in more detail. Thanks

OK.  Now I understand what you are planning to do.

In general, if you are installing a tri-amped setup like you describe (one amp for each musical range) then yes, you will need a crossover.  Get a good quality stereo crossover with three-way outputs from a company like Audio Control (their 4XS product would do nicely for you.)

You do not necessarily need an EQ.  If you WANT one, then get a stand-alone EQ like Audio Control's model Four.1i.

Thanks for the input, but I am not sure exactly what equipment as far as brands that I am getting, so I will take all suggestions. Here is the plan:

1. Use the existing head unit and install line outs for the RCA converison(I may not be using the right term, but I want to be able to connect to a crossover or amp, that depends on the suggestions I get from you).

2. Install a two channel amp to drive two 12 inch subs

3. Install a four channel amp that can drive the midrange and midbass speakers.

4. Install a two channel amp that will drive tweeters

I just realize after reading everyones comments, that maybe I can drop it down to two amps. I am aware of component speakers that comes with a crossover network.  Another thing, the person I am installing this for is a musician, so they want to be able to tune their system based on what song they are listening to at that time. They listen to types of music from R&B to rock. That is whay I was considering the eq and crossover. I would like to install this type of unit in a convenient location. I will remember next time to include the application.

Here's what I would do:

1.  Install a good 4-channel amp for your main speakers.  Use the high-pass crossover built into the amp set to about 80 to 100 Hz.

2.  Install a good mono sub amp for the subs.  Use the built-in low pass crossover set to 80 to 100 Hz.

3.  Install a good stereo equalizer in the dash next to the head unit so the owner can tailor the sound to their liking.