6 4" aero ports & 6 DD1508's?

[oxsign 1]

I'm going to be doing a box for 6 1508's and I have 6 4" aero ports lying around. I was wondering if a box at 6.5cubes (after discplacment) with 6 4" aero ports would be to much?

[shizzzon 461]

i think it would. Unless you plan on running 6kw+, i dont think you need that much port area.

i cant tell ya whats ideal because i'm workin on gettin my pc back in order after a crash the other day.

[oxsign 1]

I was running off the theory of needing 12-14sq" of port for every cube. 6 4" gives me 75sq" in a 6.5cube box.

[stovebolt6 3]

I was running off the theory of needing 12-14sq" of port for every cube. 6 4" gives me 75sq" in a 6.5cube box.

it is a very good rule of thumb.

but a suggestion i would go with 6 inch ports so you can go with less.

with multiple round ports vs. one or two larger round ports.

their can be broad tuning shifts throughout the frequency range, which can cause nasty peaks that speaker programs usually don't predict.

for the sake of sq go for less larger ports to achieve your desired port area.

go for the largest diameter that box length will allow for.

[stovebolt6 3]

i think it would. Unless you plan on running 6kw+, i dont think you need that much port area.

i cant tell ya whats ideal because i'm workin on gettin my pc back in order after a crash the other day.

i believe he is right

in my personal experience one 3 inch round port is enough for one 8.

i am talking about the actual precision port style with flares.

i do not have experience with plain pvc pipe which is more prone to port noise.

[shizzzon 461]

the rule of thumb is correct, but from experience, it doesnt have to be used as the box size gets bigger and bigger and bigger unless you are also adding more and more and more power.

Now, this isn't true 100% of the time but realistically, 8s cant handle as much power as larger speakers can so it throws off the "rule of thumb".

You could always go with 1 large slot port.

[stovebolt6 3]

the rule of thumb is correct, but from experience, it doesnt have to be used as the box size gets bigger and bigger and bigger unless you are also adding more and more and more power.

Now, this isn't true 100% of the time but realistically, 8s cant handle as much power as larger speakers can so it throws off the "rule of thumb".

You could always go with 1 large slot port.

a slot port can also be easier to design into the box as some 8's require ridiculously small boxes, in turn requiring very long ports.

not saying this is true with the dd's as i have no experience with them.

[///M5 2,833]

Those will be rather long if you do all 6. Remember the aero's help limit what you need so you can reduce your rule of thumb a bunch.

[oxsign 1]

Those will be rather long if you do all 6. Remember the aero's help limit what you need so you can reduce your rule of thumb a bunch.

OK, I was looking at tuning it to 38Hz. I would like to take it down a little lower, but I know that 40Hz is recommended. How do DD's do with a lower tuning? So with aero's (Precision Ports) 4 maybe 5 would be ok with all 6 1508's? Maybe 2 separate chambers with 3 1508's & 2 4" aero's in each. I would love to go with 6" aero's, but I have these 4" here already, and I would like to utilize them if I can. Thx for the help & input guys.

[95Honda 486]

I ran (6) 4" Aero Ports with my 8 RE8s and that was about as perfect and as loud as you could do... It did 143db on the TL with 150 watts. Definetly not to much port. I had to cut those ports down a few inches from full length also, so I could have ran around 8 at full length and been just fine. I think the box was roughly 6 cubes also...

Don't put to much thought into box volume vs port area, these don't have anything to do with each other. The only thing that determains how much port area you need is the displacement of the driver. Companies recommend port area vs volume to keep idiots from running a 2" ID PVC port with an 18" driver because "WINISD said it was OK"..... Or putting a 10" ID port in a box for an 8.... Etc....