Finally, someone that agrees with me

I'll add that you can cover the whole frequency range with rear speakers or a tweeter you can cross low but there's no substitute for a speaker pointed right at you a good distance away for imaging...

That's almost exactly what I have. As for the 6.5", I'm assuming you're talking about a woofer with strong midbass in IB applications--something sorta like the Adire Kodas I have in my doors

If I spent more time on the Koda install, I honestly believe I could do without subs, just letting the Kodas play from 500 on down; That's how strong their midbass output is.

As for the kick, a 5.25" would be *real* tough spacewise because of two things:
- You'd lose a lot of legroom because you're talking about a 6" footprint. Any way you do it with a woofer that big, you'd get a lot of blockage. And then you'd get a nasty dip around the mid-tweet cross frequency--eerily similar to the dip normal people get when they mount comps in the doors
- You'd have to seal it off with a decent amount of airspace, eating into your deadpedal space.

I would recommend either doing what I did (sealed-back midrange/strong midbass door combo) or using a 3 " or 4" full-range that doesn't need a lot of air like the ones made by Fostex, Eton, or Tang Band.

Mmm...a second tweeter...Yes, I'd love to pull up my soundstage. The a-pillar might put your driver side tweeter way too close compared to the passenger side tweeter...and you'd probably get a drastically different sound at speed...

I'd also consider sticking them way back on the dash, just so the difference in distance isn't so bad...

Whatever way you decide, I'd be real interested in seeing the results
Even so, I'd love an EQ but would be tough to fit one up front and my trunk's almost as full as it's gonna get.

My deck has a silly, little 7-band EQ that works at the frequencies it has but doesn't have anything at 500 Hz, where I really need some tweaking--a by-product of having an on-axis midrange and an off-axis midbass...Last I got measured, there was a 4 dB dip at 500 Hz...

 

b0mbrman,

As the saying goes "Great minds think alike"

Putting a 5 1/4" is going to eliminate the dead pedal but that is something I'm willing to live with. When I did the system in my Si I lost the dead pedal but after a while I got used to it.

Putting a tweeter in a-pillar would make it closer but what I'm planning on is a competition level system where both sides are judge, a judge in both seats. The deck I'm going to run will have the time alinement feature in it so that when I'm by myself, with a passneger or in the lanes I can make the adjustment to fit the situation.

500hz seems to be the one thing that always needs some tweeking. My friend does all my tuning, where I do the system design and it seems to work out that way. He does such a good job tuning a system that his setup that consisted of 5 1/4" in the kicks, 6 1/2" in the doors and 2 12's in a bandpass was up to competition SQ levels. I still don't know how he did it but for a bandpass system it didn't sound like it. 500hz is his favorite fequency to tune and also it is the fequency he hates the most. If a system doesn't have an adjustment for that fequency, let's just say don't get him started, so I know your pain without the adjustment.

 

Bump! Just so it's easy for me to find this when I get home from work

 

Take a look at this site for information on sound wavelengths:
http://www.mcsquared.com/wavelength.htm

If you plug in various frequencies, you get the wavelengths of the sound wave generated:
500 Hz - 27.12 inches
1000 Hz - 13.56"
2000 Hz - 6.78"
4000 Hz - 3.39"
8000 Hz - 1.69
16000 Hz - 0.85"

Anyway, to get to my point, as your sound source produces higher frequencies, the wavelengths get shorter and shorter. It appears that probably for human dimensions, about 4000 Hz is the limit at which the variability in your head position would negate any changes in phase tweaking. If your tweeter's output is 4000 Hz or above, your head would need to be locked into a Mayfield headrest to discern any audible difference.

 

Yes, the mounting location and direction wouldn't matter in those higher frequencies if there were no dispersion rolloff. Let's look at some frequency response graphs. I chose Vifa drivers because their parts go into some of the more popular comp sets out there (Infinity, JBL, and CDT to name a few). In these graphs, the blue is the on-axis response, green is the 30