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No airflow from port - driving me crazy


DynamikT

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I have 2 power acoustic mofo 12's in a 3.9 cubic box.. I can see them both move alot but hardly any volume is coming out of them? When i just have one hooked up it sounds MUCH louder than both of them, ive done the wiring correct, my amplifier is underpowering them but even so when they are moving this much, i know it should be alot louder. Below are my box specs...

I read somewhere there is a possibility of a box being too small so then a push/pull config has to be done where one sub is flipped, is this my only solution in this particular box? Thanks.

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Sounds like one of then is out of phase

What he said, swap the pos and neg on one of the subs

Brandon

2000 Furd Ranger supercab 4x4

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The port area may also be to large. Even though the enclosure is "tuned" to 30 hz, if the port isnt the proper size according to the drivers, such problems will arise.

Aviod enclosure calculators that dont take the driver into its calcualtions.

Also, what kind of amplfier do you have?

Avalanche

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move the port

09 Challenger R/T (Audio system under construction):

  • Pioneer AVH-X4500BT (PAC RP4CH11 harness)
  • (2) Sundown Audio SA-8v2 (inverted)
  • CT Sounds AT1400.1D
  • XS Power D3400
  • 40 sq ft. Audiotechnix deadener
  • 1/0 Audiotechnix wiring
  • stock Boston Acoustic 7 speaker amplified system (for now)
  • Sealed trunk enclosure

Build log:

http://www.stevemeadedesigns.com/board/topic/178399-slammed-dodge-challenger-sundownct-sounds-build/

TEAM GOAT

signature-1.jpgsubsignature.jpg

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The port area may also be to large. Even though the enclosure is "tuned" to 30 hz, if the port isnt the proper size according to the drivers, such problems will arise.

Aviod enclosure calculators that dont take the driver into its calcualtions.

Also, what kind of amplfier do you have?

While the needed port area for the subs should be 49 in2 at 30hz, having 36 inches will increase velocity of the air.

OP if you are not having air flow, then you most likely have one of the subwoofers wired backwards causing the phases to be 180 degrees away from each other.

This means that when one subwoofer has the cone being pushed outwards the other is being pushed in, causing the pressure to be canceled out.

I noticed you said "push/pull" configuration in the beginning, this would be wiring out of phase. You need both of the cones to be moving in the same direction at the same time.

b_350_20_692108_381007_FFFFFF_000000.png

Krakin's Home Dipole Project

http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370

Krakin, are you some sort of mad scientist?

I would have replied earlier, but I was measuring the output of my amp with a yardstick . . .

What you hear is not the air pressure variation in itself

but what has drawn your attention

in the two streams of superimposed air pressure variations at your eardrums

An acoustic event has dimensions of Time, Tone, Loudness and Space

Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears,

thus no formula can achieve a definite effect for every listener.

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Ive actually made a box for these exact woofers

I gave them 2 cuft each after all displacements

but I gave them 64 sq of port area

they loved it

kicker u lite app on your phone shows wiring diagrams to help

asks what coils are on the woofer/s and what resistance you need to the amp

CAR AUDIO JUNKIE

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