too much port area? need help

[skippy90210 10+ year member]

so i built an enclosure for 4 alpine type s 12s. it has an 8 inch diameter aero port im thinking it might be too big because it does not hit low notes as well as i wanted. the port is 19 inches long and the box after displacements is a little under 5 cubes i have them wired to 2 ohm 2000w so 500w each just as rated. could my large port be the problem with my subs not hitting the lows good? my box dimensions are 33 wide 21 tall 14 top depth and 22 bottom depth, i put it in a sub box calculator and it says its tuned to 33hz

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[CSCStang]

so i built an enclosure for 4 alpine type s 12s. it has an 8 inch diameter aero port im thinking it might be too big because it does aero low notes as well as i wanted. the port is 19 inches long and the box after displacements is a little under 5 cubes i have them wired to 2 ohm 2000w so 500w each just as rated. could my large port be the problem with my subs not hitting the lows good? my box dimensions are 33 wide 21 tall 14 top depth and 22 bottom depth, i put it in a sub box calculator and it says its tuned to 33hz

5.86 gross cubes. Roughly 4.6 after disp. Box is way too small for 4 12's, that's why you're not hitting lows. You're also at nearly 11" port per cube. With an aero that's too much for those S' s.

 

[skippy90210 10+ year member]

so its a design flaw on my end what should i do to fix it? the manual says 1 to 1.5 cubes per sub ported so i thought that was enough air space, just a smaller port?

 

[LosIsATool 5,000+ posts]

Alpine like every other big name will tell you to use way smaller than they need, it's a selling point. They know most the use them have no idea what good bass is, and will just stick them in a prefab

 

[skippy90210 10+ year member]

well im in a situation then idk what to do lol i have 4 subs with a box too small and a port too big lol

 

[skippy90210 10+ year member]

would 2 type r 12's in the same box be better than what i have now?

 

[hispls 5,000+ posts]

The port isn't too big, the box is too small. The whole ratio of port area to box volume rather assumes that you have correct/adequate box volume for your subs.

I would suspect that if there's no other problems with the box it would perform better with a single 15 or pair of 12's.

 

[skippy90210 10+ year member]

Well I could do 2 type r 12s will they take 1500w rms each?

 

[LosIsATool 5,000+ posts]

What amp?

 

[Buck 5,000+ posts]

would 2 type r 12's in the same box be better than what i have now?

Yes.

 

[JoshC 10+ year member]

would 2 type r 12's in the same box be better than what i have now?

That would be about right, cover up two holes and give it a go

 

[Jeffdachef 5,000+ posts]

so its a design flaw on my end what should i do to fix it? the manual says 1 to 1.5 cubes per sub ported so i thought that was enough air space, just a smaller port?

nope their manuals specs ****. You'd want at least 1.5 or more for a 12.

here are some temporary solutions for you

-Unwire two of those subs and only run the other two

-Invert the subs so the motor is on the outside and switch over to three 4" round ports around 13 inches long each. If you can have the ports stick out externally

 

[wew lad 5,000+ posts]

he could stuff the box, if he has 4.5 cubes net total, he could get up to .9 cubes extra by stuffing it with fill but it might be too small still

 

[Jeffdachef 5,000+ posts]

he could stuff the box, if he has 4.5 cubes net total, he could get up to .9 cubes extra by stuffing it with fill but it might be too small still

Doesnt work as well in ported. Makes minimal difference with the polyfill batting on walls, Too much impedes airflow too so its not really a solution.

 

[skippy90210 10+ year member]

Well I could do 2 type r 12s will they take 1500w rms each?

Hifonics brutus 3000w