That's a huge step you're taking. I'm surprised nobody here has asked some very important questions.
1. Where is your midrange going to be located? Will it be on-axis, off-axis, and if off-axis to what degree?
2. Where will your tweeters be located? Same question applies as to question number 1.
If you're new to active tuning, and have never ran a 3-way, spending $1500.00 on raw drivers is borderline ridiculous. I mean, I can't tell you what to do with your money, but you can get GREAT quality for MUCH, MUCH less, and you don't have to sweat every decision. It's much better to test your mounting locations and listening desires with a set of Vifa MG10 midranges for around $60.00 a pair, than find out you don't like the $400.00 pair of Scan Revs, or other comparable speaker.
Be careful with tweeters. Many high end tweeters cost a lot, not because they sound that much better across their bandwidth than their lower priced counterparts, but rather they sound better at lower frequencies. For example, the Cal28, Lotus RT27F, etc can drop very low for a tweeter (i.e. the 1500-2000 hz range), and maintain excellent clarity. In a 3-way that benefit is useless as you won't be crossing a tweeter until 4k and up (depending on your midrange). So, is the Cal28 tweeter that much better than a set of LPGs that cost 1/10th the price? The benefit the Cal28 tweeter has over the LPG really is the extra 1000-1500 hz of lower end bandwidth. If you like the Rainbow tweeters, look at the Cal25, and Cal26 for a 3-way setup.
Midbasses, midbasses, midbasses. Again, why spend the money on a set of midwoofers designed to extend up to 2-3k, when you're going to be crossing them over at around 200-250 hz anyway. The Scan Revs are fantastic, but are wasted in a 3-way. Same with the Seas Excel line, and many of the Rainbow offerings. So, again, look for drivers that have limited bandwidth. They'll save you money, and generally have better reproduction of the frequencies you're focusing on. The Peerless SLS 8 has already been mentioned. They also make a 6.5" SLS version that is fantastic. Midbass doesn't get much better than these.
http://www.madisound.com/catalog/product_info.php?manufacturers_id=143&products_id=8234
Again if you like Rainbow, the Rainbow Profi Kick is a great speaker. Doesn't dig as deep as the SLS driver, but is very snappy and very accurate. Again, though, the Rainbow Kick is much cheaper than a lot of higher end offerings that give you performance where you don't need them.
The real question though is, which midrange? That's the driver that will be handling most of your bandwidth, to include the critical vocal range. I suggest starting cheaper and going up from there once you figure out what you like and don't like. One of my all time favorites is the Vifa MG10. The MG series is what the CDT ES series is designed from, for a 1/4 of the price. It's the one driver from CDT that I actually like, and that's because I really like the Vifa MG10. Even better though, is they're on sale right now for a mere $28.00 each.
http://www.madisound.com/catalog/product_info.php?products_id=1118
Yeah, it's shielded, but for the price, it's an EXCELLENT choice for a first time active/DIY setup. You can be as critical as you like with that driver, and then you can come back and say "Hey guys, I want to upgrade my midgrange. I'm currently using the Vifa MG10, and this is what I like about it, and this is what I don't like about it." Until then, people suggesting $200.00 drivers are just suggesting them because they're $200.00. Listening is subjective, and it's rather irresponsible (sorry guys), to suggest a speaker costing that much without having a more detailed description of listening tastes, to include comparisons with other drivers.
Next, you really need to ask yourself, will this be a competition car, or a daily driver. If it's a daily driver, then ask yourself, how much is a fraction of a difference in "inaudible" distortion when driving down the road worth? The Scan Revs boast some, if not the best, distortion figures in the industry. However, even in a well built home audio room, only the most critical listener can really tell the difference in distortion between a driver like the Scan Rev, and the Vifa MG10. In a car, it's nigh impossible.
So, that leads to install. The best gear in the world doesn't mean doo-doo if you don't install it in a manner conducive to it's performance. You shouldn't be sweating driver selection. You should be in a near panic thinking about the time and energy you're going to have to put into your car BEFORE the drivers even touch the car.
Just my .02.
Anybody willing to help?
