Flared Port Help

[vanquish 0]

Hows this sound to you guys.

(2)15 Bls

Box:

17x39x22 = 6.54cubes (after displacement)

Will (2)4in flared ports be enough port area or not enough?

suggestions please

[KennyC 0]

Hows this sound to you guys.

(2)15 Bls

Box:

17x39x22 = 6.54cubes (after displacement)

Will (2)4in flared ports be enough port area or not enough?

suggestions please

The square port inches for a 4" would be approximately 12.6in^2

Aeroports have been proven to move quite a bit air...some have shown it to be 60% more efficient. So lets say the 4" can account for 20.1in^2 of a normal slot port. 2 would put you at about 40.2. For a box of that size if you go off 15 cubic inches per cubic foot you will need approximately 98"

You could go with about 5 4" ports

or

6" port = 28.26in^2 == 45.2in^2 slot

2 6" would give you about 90 where as the 5 4" would give you about 100.

Hope that helps a little bit. I'm a bit tired and hope the math works out. The 2 6" I think would work best and be the cheapest/most efficient route to go.

[95Honda 486]

Honestly, the only thing that determains the minimum vent area needed is the amount of displacement your subwoofer will have. I always wonder who made up the ratio of box size to vent area, it is pretty meaningless.

Ok, here goes. You want enough vent area to keep the vent velocity (how fast air moves through the port) down low enough that it doesn't introduce a noticable amount of compression. This compression is bad because it will begin to alter the box response.

The vent velocity is determained by two things and two things only, #1 the amount of driver displacement (how much the air the sub is moving) and the area of the vent. Box size has nothing to due with this, hence recomended vent area has nothing to due with box size.

So, how does this relate to your question? Will a pair of 4" Aeroports work for you, in short, No. BUT, this is only if you are going to be driving those subs to full displacement. At this point a single pair of 4" ports will probably introduce a fair amount of compression and begin to alter the box response, and probably give a signifigant drop in efficiency over what the ported alignment should give. BUT, if the drivers are only driven to say 1/2 of thier full displacment, than a pair of 4" ports would be fine, but that is likely not the (your) case. Either way, 100in2 would probably be a little overkill, but nothing wrong with it.

The best solution would be for you to download a copy of WINISD and start looking at the predicted vent velocity for the different port configurations you would like to run. I think (IIRC) it will give a recomended maximum vent velocity and you can see where you end up. You will also notice that if you change power input or vent area that the velocity will change, but if you change the box volume it stays the same....

[vanquish 0]

appreciate the input guys.