Box build advice plz?

[ThoraciasDimial]

I have been competing since 2006 but have always had someone else build my boxes (I am no carpenter!) and for the first time, my husband and I are going to have a hand in the actual build through a friend who runs a woodworking shop. (Hence, WE know nothing about woodworking...HE knows nothing about SPL competition. LOL)

So we have a design sort of in mind and we have had the slot vs. aeroport debate and we favor the aero's. I found a calculator online but really am not sure how to use it. I'm a total noob to this part of it. I basically like to just pull in the lane and burp it off. I'm trying to get more in depth knowledge so bare with my noobness please.

So...I have a 2005 Expedition, running two Digital Design 9515's. This the the current box (which is too conservative for our taste):

(We know the amps should NOT be mounted to the box...that's the way the "audio shop" did it and they are no longer in business so...anyway...

We want the subs up and the aeroports back as in our earlier system which was in my 1998 Blazer:

Specs on the DD site recommend 4.25 cubic feet box space, 70 sq. inches of port area and 21 inches port length BUT that is for a slot port. Any suggestions on using aeroports? Such as how many/size? I can test length a bit at a time to tune it (we have a Term Lab). We are going with one chamber instead of partitioned.

[fecupe2001]

Welcome to the forum, it´s always nice to see new female members, and specially one that competes with her husband

About your build, Those subs LOVE big ass ports, i used 2 6" aeros for a single DD 9512 and that thing was nasty, for your application, i can´t comment that much since you haven´t say the amount of power you guys use, you could build a pretty efficient box with small power or a smaller box that can take some serious power , depends on you guys.

Anyways, said that, i think i would do something like 8-8.4 cubic feet and 4 6" Aeros with something like 36-38 hz tuning, the expedition is bigger than my explorer and that´s why i say tune it around there, i know for sure that my explorer is very sensitive about tuning, no matter the box size i use, she loves to get tuned around 40 hz, but i don´t know much about expeditions so i´m just throwing ideas , maybe someone that has tried those trucks could give you a better input

[ThoraciasDimial]

Thanks for the reply!

Sorry I forgot to mention I'm pushing each 9515 with a DD M2a (2300 RMS).

Shane decided last night he wants to have a changeable port since this is my everyday driver. Now trying to figure out best slot ports.

I have a total noob question but no way to learn without asking, lol...in my Blazer we were tuned at 51 Hz and hit a constant 148-149 db. In the Expedition, we are tuned at 41 Hz and can't get above 145 Hz (hence, the rebuild). We were going to try to tune this box HIGHER but you are saying since it is a bigger vehicle, to tune it lower? Can you explain in laymen's terms the difference and why please?

And props to all the females competing...I compete by myself, not "with my husband". My husband has a show truck. I just got bored sitting around car shows with him all the time and wanted to do something else. Greg Welch (R.I.P.) of the infamous Team Welch, Kicker van "Maximus", lived just down the road from us and he built my first system. I was hooked from that day on. lol

My husband is good at wiring and I say he is my "financial backer". haha

But when it comes to box builds, we are both clueless right now!

[n8ball2013]

You may be surprised to find your peak in teh larger vehicle is much lower. throw in a larger cabin space and its tougher to pressurize. More power would really help your cause as well.

[korey_hofer]

dd's box specs are only for break in, they sound like crap.

try 7ft 140'' of port

sub/port back tuned to lower 30's

you will love the subs after that

I'd do port on drivers side subs on passenger side

[korey_hofer]

if you want a box design let me know I would much rather do one for free and you be happy then some one else charging you and you ending up un happy

[fecupe2001]

You may be surprised to find your peak in teh larger vehicle is much lower. throw in a larger cabin space and its tougher to pressurize. More power would really help your cause as well.

This!!!

As i told you before,my explorer it´s a smaller SUV and still hates anything tuned above 40 hz, i haven´t try any expedition, but since is much bigger i would tune it on mid 30´s , korey just gave you a nice offer there, the guy knows his stuff and can design you the box for free.

About the m2´s for the subs, that isn´t much power but those amps are very nice, my best friend has a nissan almera with 2 9515´s and 2 m2´s hitting 149.5 in a trunk car on a daily box, his exact specs are this just in case you want to know them are 3.5 cubic feet per sub and 100SQ of port, that´s one tiny port for those subs but it was the biggest he could go in that trunk, and still scores very nice IMO, 140SQ of port as korey says sounds correct!!