help me get loud please.

[sikcavy 10+ year member]

I have a 03 cavalier with a g34 yellow top and a single 3512 running at .7ohms on a very old school us amps 100hc running maybe a little over 1k watts. i built 2 boxes so far for this one 12" (was testing with a 12" bass mekanik before) one for street bass so it wasn't that loud on the TL. The SPL box (what I'm currently messing around with) is 2.5 cubic feet double walled (doubled up on mdf so 1.5" walls all around) tuned to 55. The sub is firing into the cabin on the passanger side and the vent which is 72^2 inches is on the drivers side of the box. I am following db drag rules so everythign is sealed up and mic on the windshield. I peaked at 43hz so that tells me the box is tuned too high. I reached a score of 141.0 I then took a piece of mdf the length and height of the box and put it in the vent. This brought the area to be 63^2 inches and the tuning was dropped to 50. I tested and came out with same results. I then upgraded my wiring from 4 gauge all around, to 0 gauge all around i gained .5db's. i have another plug that I will be throwing in the vent monday to drop the tunning to 44. i will then update you guys with the outcome and go from there. I plan on building another box but this time having the sub and the vent firing towards the cabin sealed off from the trunk. I just don't know if I should run a box at 2.5 cubic feet or smaller. i will be using a 6" precision port and start from 30 and cut away until I dont get any more increases. So my question for you guys is what would you recommend 2.5 cubic foot box or smaller?

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[boomzilla 10+ year member]

Small box, big port, and alot of power. Try a little smaller, around 1.75, tune it to the res. freq. of the car, and have around 1000-2000rms. Usually in a trunk two 12's on 2000rms ported gets in the high 140's, but depending on the install and how much money you have, it can be either or.

 

[thegreatestpenn 5,000+ posts]

your score isn't bad. tuning on the spl box is really hi and the box is too large. remember spl boxes are generally very small and tuned like 5-10Hz below car's optimal tuning in most cases. sealing off the trunk should help drastically. more power would help drastically too.

 

[sikcavy 10+ year member]

there is no option of more power. there are some comps i go to that class you by power and i want to stay in my class.. so you guys recommend me going to 2 cubic feet with a 6" port?

 

[boomzilla 10+ year member]

Then try smaller boxes with the new tuning and test it out. There's no definate answer as to if it's gonna be 3db's louder or not, there's so many variables that come into play when pressurizing high amounts of air, you just have to try it out and see what works best.

 

[WildSebring 10+ year member]

I have done exactly what you are trying to accomplish.

I had a single 12" in the trunk in a SPL box tuned to 60Hz @ 2.5 cubes. Scored like a 146 with 2 Sundown 1500's strapped to it.

Sealed off the trunk, SPL-X firing into the cabin, made box smaller to 1.75 cubes and tryed again. This time I prevailed with a 151.3. Loudest I ever had it, just throw big power and seal off the trunk..

I miss that set-up.. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[thegreatestpenn 5,000+ posts]

what league are you in? It sounds like IASCA and if so they use the amp's 4ohm power rating so as long as the power rating at 4ohm is within your division's limits you are good. I ran a 1500wrms amp in the lowest division because at 4ohm it was only rated to do 500wrms

 

[sikcavy 10+ year member]

do you guys recommend 2 4" or 1 6" ports?

 

[thegreatestpenn 5,000+ posts]

1 6" has more port area than 2 4"s so go with the single 6". even tho my box has 2 4"s and it gets plenty loud //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[sikcavy 10+ year member]

the only issue with that is i will have to make the box longer to be able to use a long 6" vs having 2x shorter 4"

 

[thegreatestpenn 5,000+ posts]

yeah there's always sacrifices to be made when getting loud.

 

[WildSebring 10+ year member]

2 4" PSP Ports would work plenty well. Thats what I used..

 

[sikcavy 10+ year member]

is there any difference between 6" port and 4x 3" ports? same area just smaller ports but with more.. would there be a bad side to this?

 

[thegreatestpenn 5,000+ posts]

if you can find a way to get them all on the same plane I don't see a problem with it.

 

[thorshammer1 10+ year member]

I tune my box in the vehicle. I seal all sides but the back and the port wall ( I like slot ports ) and test and cut till I peak out. Hope that helps.