Thats for one DD2512? Sounds good. 3.57 cu ft for one 12", thats large but not to large, maybe if u make it about 3 cu ft even, the bass will be a little tighter.
35 hz is a good starting point. Have you thought about making a box with an adjustable port?

PS... Torres Calculator is badass

3.57 is gross volume, it'* actually 2.4 net.....gross is the overall volume of the box based on external measurements, net is the internal volume after all displacements are calculated, including port, sub and any bracing.




How do you figure that? Dude, 3 cubes is way too large of a box for a sub that'* spec'd to be in a box between 1.75 and 2.5 cubes, ESPECIALLY when you're giving it twice rated power!

Good starting point huh? No, haven't thought about doing that...it'* a great idea but I'm not too sure that I have the knowledge and/or abilities to pull that off well.

I know what gross and net volumes are but i didnt realise it was net volume, thats why i said u should make it a lil smaller for sound quality reasons.
So there my reply to ur first 2 quotes. lol. My box was tuned to 35hz and i really liked it. played all audible frequencies very well, but really had strong impact down low.
Ive never seen an adjustable port box in person so i dont know how they rate

Personally I like lower tunings, but that looks good to me.

What you could do for adjustable port is make it so the port has no common walls with the enclosure. Then put the four walls of the port together and put a "flange" on it that you would then attach to the box with bolts and t-nuts (as well as something to seal it, some rubber weatherstrip or something?) Make different length ones for whatever tunings you want and you should be able to easily swap them out should you ever so desire.

I apologize if that didn't make sense, I have had the idea in my head but no idea how to word it.

Not all subs are created equal, guys. DD is the sister company to AQ, and I know that AQ subs need to be tuned higher than most other subs. 34/35 hz is about as low as you will see people tune AQ subs. Most people tune them in the 37/38 hz region (from what I've seen). They are stiff, higher FS subs and need bigger boxes and higher tuning. From what I've read, they can play pretty far under box tuning as long as the box is built properly.

FWIW, most people would also say that tuning a Fi Q to 35 hz is too high. I've always seen 30-32 hz recommended for Qs. IIRC, Nick from Fi told someone planning to tune to 34 or 35 hz that he should tune lower than that. But, if you liked it, that'* all that matters.

Monte, perhaps you should try using an ugly temp box with an external aero port for tuning, and start with a long tube (low tune) and trim it off every week or so and get an idea of the different tuning possibilities. I guess the only downside would be trunk space/positioning for that. You may end up liking a certain box size/tuning and then go build a slot port box and the orientation/location in the trunk totally changes the sound....

Well said. DD subs are truly a unique beast, they're in a lane of their own indeed. The thing that really trips people out about DD subs is their high FS cause like you said, they play well below that unlike most others.

I'm just going to build this, if I don't like it then I'll go from there

Here ya go!
http://caraudiomag.com/articles/seal...rted-enclosure

Here is my new enclosure for my P3'*

That'* how my existing box is

That link you gave for the sealed/ported box, that'* pretty sick