DD 1508s box help please

[jordan.guess 1]

Hello, I just purchased two DD 1508's and am going to be putting them in my 1987 single cab toyota pick-up. I am short so it allows me to have my seat pretty far forward and I can get quite a bit of room back there. DD suggests that I put them in a ported enclosure and tune it to roughly 38 hz. Has anyone experimented with 8's and know of a better frequency to tune them at? If not I will just go with the 38. Next, I couldn't find an exact xmax on these but after reading around I discovered its about 15mm so on my port calculator it suggests I use roughly a 4" port at 20.5 inches long if I am putting it in a 1 cubic foot box. My main questions are these: will 4" pvc pipe at 20.5 inches long suffice at 1 cu ft.?, should I make a box separate for each sub or put them both in the same box and just make it bigger?, and lastly has anyone had better experience with completely different enclosure volumes and port sizes for 8's? Also if anyone would happen to have the sub displacement volume on these subs that would be great. Sorry for the nooby questions but I am just struggling on how I can get this to work in my vehicle. thanks!

[audio-neon 34]

Is your port calculator accounting for a round port?...

1 cu foot per driver seems on the large side for an 8, but not too large, especially if the box was 1 cu foot before port displacement and driver displacement of (0.03 cu ft) were removed.

They drivers are pretty rugged, but what are you planning on powering them with just out of curiousity? and final inteneded impedance?

[jordan.guess 1]

they are D4's and i have a JL 1000/1....i just have NO IDEA how to tune it cause of the many knobs on it D=

edit: and yes thats for a round port

Edited April 25, 2012 by Jordan Guess

[audio-neon 34]

d4's will allow you a 1-ohm final imedance, which I believe that amp is stable to.

Basically just set your ssf @ 30 hz, your low pass @ 80-100hz...

bass boost to 0 and add "gain until you hear distortion, than back off"

That's your basic amp set up.

[jordan.guess 1]

there is no ssf, gain, or low pass on the amp. thats why i find it confusing

[audio-neon 34]

Do you have a JL audio 1000/1 v1 or v2? If you could just post a close up picture of the knobs/rca's I can walk you through what JL audio might call these settings.

[Shogen 325]

I have/had JL 500/1 which is the baby version and it has a SSF ... believe it's labeled as "subsonic" .... Can't remember that 100% though...

[jordan.guess 1]

its the 1000/ v1 im pretty sure because on the amp itself it only shows 1000/1 and ive seen some that will have 1000/1v2, your assistance would be much appreciated!

[jordan.guess 1]

http://www.kenwood.lt/files/public/1262448052_2516_FT0_img_0567.jpg

[Shogen 325]

My badd.. it's labeled as "infrasonic filter" ... put it in the "ON" position and adjust the knob near it in the 30's range...