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dfoland93
03-21-2012, 01:53 AM
Is their a certain box and port set up to optimize an SPL build? Like what kind of port? Is their certain wood that is better? I heard baltic birch hits higher on the scale.

9515ROB
03-21-2012, 02:04 AM
13 ply birch is best but its hard to find. Most the stuff from lowes is like 9ply but still is super strong. Best part about it is its super light way compared to mdf

9515ROB
03-21-2012, 02:05 AM
and find out what your car peaks at and tune a couple hz lower.

Small box big port tuned high. Thats what spl boxes are

CAT MAN
03-21-2012, 02:39 AM
and find out what your car peaks at and tune a couple hz lower.

Small box big port tuned high. Thats what spl boxes are

not always. sometimes its big box big port its all dependant on how it will be used.


mdf is (imo) the best for small spl builds and birch/pine for bigger walls and such. usually aeros are used so you can change tuning whenever

9515ROB
03-21-2012, 03:04 AM
not always. sometimes its big box big port its all dependant on how it will be used.


mdf is (imo) the best for small spl builds and birch/pine for bigger walls and such. usually aeros are used so you can change tuning whenever

Big boxes are for people that dont have enough power to get there sub loud. The bigger boxes allow them to produce more sound on little power. Little boxes allow the sub to handle more power

And birch is a far better material to use. They are about the same density as mdf but the weight you save and how much stronger birch is makes a huge difference. Birch is much easier to work with as well. Cuts so much easier.

If he wants to get real fancy he can use steel or granite

CAT MAN
03-21-2012, 03:17 AM
Big boxes are for people that dont have enough power to get there sub loud. The bigger boxes allow them to produce more sound on little power. Little boxes allow the sub to handle more power

And birch is a far better material to use. They are about the same density as mdf but the weight you save and how much stronger birch is makes a huge difference. Birch is much easier to work with as well. Cuts so much easier.

If he wants to get real fancy he can use steel or granite

exactly the point ;) but on small spl builds mdf wil lbe more effective for the cost. birch is 51 a sheet here and sorry im not goin to pay that to lose 30 lbs lol

subzero
03-21-2012, 03:28 AM
SPL also require the vehicals enviorment to be primed for spl conditions for maximum gain

Heel4lyfe
03-21-2012, 11:35 AM
and find out what your car peaks at and tune a couple hz lower.

Small box big port tuned high. Thats what spl boxes are

how does someone do this???

Joseph7195
03-21-2012, 12:27 PM
Go to someone with a termlab and have them check it. You will want to do all your sound deadening and other major modifications for SPL finished before you get it checked. But when you have the resonant frequency of an exterior enclosure(vehicle) you pretty much just put a sub(usually a 12") in a sealed box inside the vehicle at different locations all while running frequency sweeps and graph the results. The sweeps are usually just 20 hz to 80hz, and peaks in SPL, at certain frequencies denotes the peak resonant frequency.

But as mentioned before, certain factors will change the resonant frequency drastically, such as but not limited to, air temp, humidity, fat chick in front seat, and even something as small as the visors being down. This is why most people will just run a box with an aeroport because the ability to change the port length and tuning is easier. Hope this helps!

dfoland93
03-22-2012, 03:03 AM
Well my set up will be:

(2) RE SX 15" D2
(2) Hifonics BRZ 1200.1D
(1) Kinetik khc1400
(1) Singer 200A alt
0 gauge knuconceptz (big 3)
4 gauge knuconceptz (amp wire)
8 gauge CCA (speaker wire)
25sq ft audio technix deadener

Joseph7195
03-22-2012, 06:45 AM
You should be able to pull some descent numbers with that set-up, but you are definitely gonna need more power. I would check out the rule book for the sanctioning body you wish to compete in. Like in USACI, the cutoff I believe would be 2,000 to 4,000 watts in modified and super modified. It wouldn't help you any to run this category with 2,000 when everyone else will be running max at 4,000 watts. It would be hard to stay competitive. And just to let you know, USACI also doesn't use the 1 ohm power rating to classify you. You will be put in your category according to what your amp puts out on one channel at 4 ohms. which would be 450 watts per BRZ which gets you to 900. You could probably run 2 more of those amps and be at 1800 watts and qualify for the Stock 601-1800 watt division. Here is a link to there Rule book:

United States Autosound Competition International (USACi) - Store Order Form (http://www.soundoff.org/rules.htm)

It's really not hard to compete and be successful, just make sure you have a really good enclosure designer. When it comes down to it, the enclosure will make it or break it for you. I hope you can find some really good shows to go to. There are some really good folks out there that do this and are really good people to have as friends. I hope this helps you some more!