QUOTE (nate @ Dec 28 2007, 09:15 AM)

I have been hearing about the axis and positioning of the focals, or something to that notion, I will be setting my front stage up very soon and would like to get a bit of info on angles, and positioning. I do know it ultimately depend on what i like but i little info would be great. It is going into a hilux surf, and was thinking of putting the mid bass drivers down the bottom (obvious i know!) and the tweeter at the in the triangle thing, same level as the bottom of the window.
Running passive, I assume?
Angle of the midbass is not a major priority - the impact would be minimal (if noticable).
Angling of the midrange however, is aboslutely critical and the biggest factor influencing the performance of the K2P mids. Some sets use low midrange-tweeter crossover points (such as Morel Elate, @ 1.8khz) which lie more or less around the point of beaming (where off axis response becomes an issue). The result is that when mounted heavilly off axis, these don't suffer as badly because the tweeters essentially take over before off axis roll-off can become a major issue. The down side of this, however is that at such low frequencies all but a handful of tweeters (mostly Scanspeak and Seas home audio tweeters) will display horrendus distortion figures and significantly reduced power handling when played down to such low frequencies, resulting in a coloured midrange.
The Focal's (at least in the case of the K2P / K3P) use a high crossover point and a steep slope of a steep slope of 3.2k/3.8k (cant remember which) @ 18dB /oct. The result is far reduced tweeter distotion and power handling, but at the sacrifice of mounting flexablity. With a 6.5" mid typically beginning to beam around 1.5khz, you have a bit of an issue... if mounted heavilly off axis, then you will see a massive loss in midrange production (could be as much as 10dB) by the time the mids reach the 3khz+ crossover point. The steep slope also means that they don't get much extra assistance from the tweeters (as opposed to say dyn's, with a 6dB slope) and so you end up with a 'black hole' froma bout 2khz up to the crossover point where you have a significant loss in information. Don't even bother trying to EQ it up either... EQ is a problem patcher rather then a problem fixer, and the drop off will be too significant to allow EQ to be effectively solve the issue.
The solution is to get the mids running as close to on axis as possible... on axis the 165K2P has one of the best midrange responses of any car audio mids i've seen, with a nice smooth response from about 100hz to about 3.5khz, and an upper end response comparable to many 4" mids (hence why they use the 6.5" rather then 4" as a midrange in the K3P set).
The tweeters aren't as simple.. they aren't bad, but they do have their flaws and it's pretty much impossible to get the 'perfect' out of the box without EQ. On axis, they play hapilly to 20khz, but get peaky from about 5k-6k upwards. It's not bad, but it's noticable and will give give the sound a slighly bright tone. 45deg off axis the top end peakiness is greatly improved (almost eliminated), however the side effect is a rapid roll-off above 14khz. If I had to choose between the two I'd probably go on axis, because the on-axis peakiness is nowhre near as dramatic as the off axis roll off, but an even better option (if you can) would be to try to reach a middle ground - somewhere around 20deg off axis should bring the top end down JUST enough to take out the brightness, while minimising the amount of high frequency roll off, providing the best overall trade off.
As far as angles go, that'd be the path i'd go if it were my own car. I've heard the 2-way K2P's in a good listening room, and at about 15deg off axis, they are the best sounding car set i've heard being more accurate then sets costing 2x-3x the price.
On axis they are good but a tad bright, and 90 deg off axis they are poo poo.