Help with Crossovers

[NextGen]

I installed a Pioneer Z1 into my X. Next year I plan on upgrading the rest of the sound system. I want to get an aftermarket amp to power the door and dash speakers. I was thinking of getting a 4 channel amp and then using one of these crossovers to split the signal to the speakers, http://www.audiopipe.co.uk/Productlist.aspx?ChildID=25.

I was thinking of using the CR-3003 for the front speakers and the CR-2002 for the rear. These are for sale on ebay and display a different frequency range for some of the connections (in parathesis below).

CR-2002
Tweeter - 20KHz - 3.5KHz (ebay 4.5kHz)
Midrange - 3.5KHz - 500HZ

CR-2003
Tweeter - 20KHz - 4.5KHz (ebay 3KHz)
Midrange - 3.5KHz - 500Hz
Woofer - 700Hz - 20Hz

1. Is this a good or bad idea?
2. Does anyone know if these are quality crossovers? If not can you recommend better?
3. Is it bad using different crossovers for front and rear?
4. Would I be better off using CR-2003 for front and rear and then leave the midrange unconnect for the rear speakers? Is it okay to leave a connection unused (no impact on ohms or anything like that)?

Sorry for so many questions, I am a noob when it comes to crossovers!

[Bill Valley]

I would recommend against upgrading the amp while retaining the stock speakers. Purchase a couple of sets of component speakers. These sets come with their own crossovers.

If you are replacing the speakers, then an additional crossover would not be necessary. Your amplifier will have a high-pass/low-pass setting and the component crossover takes care of the rest.

[NextGen]

Thanks Bill. I do plan to upgrade the speakers at the same time. So just get speakers that have a built in passive crossover. Sounds pretty simple, I didn't think most speakers came with crossovers. If the speakers have their own crossovers then it doesn't matter if the amp has a high\low filter setting does it (or do all amps come with this feature)?

[Bill Valley]

Component speakers will come with an outboard crossover. With a component set you will get midwoofers, tweeters, and the crossover. Most manufacturers of audio equipment will offer a component set. Check out www.sounddomain.com for some good info. There is a forum on that site that has tons of info.

Most amplifiers have some sort of crossover built in. Amps have a low pass filter for subs that will roll off high frequencies. Amps also have a high pass crossover to prevent low frequencies from going to coax or component speakers.

The crossover included with component sets will further filter the frequencies; sending highs to the tweets (3500Hz and up). Check out www.bsae1.com for more info than you really want.

[NextGen]

Thanks Bill I'll look into those. It still seems to me that I can't use the amp's filters because of the way the X is setup. There are both tweeters and woofers in the front and rear channels. This prevents configuring an amp to favor one or the other. Instead, I need to send the full range to each channel and then let the speaker's crossover handle it. This analysis is based on using a single 4 channel amp.