4th order... Aero vs. slot vs. square port.

[rickymac21 10+ year member]

First off I came to the conclusion 2 15" won't fit in a fourth order in my trunk. So I switched to 2 12's. I'm liking the Skar vvx's as they have super low fs and high qts so it should be loud as balls on lows. But I'm still considering AB tnt's since they have 3" coils.

But down to business. I'm curious as to which port works best in 4th orders? I can't find a direct answer. I personally like aero ports as I've always been told they are typically more efficient. But if I use an aero, how many sq inches per cube ? I know it's more than a regular ported box, but what's the magical number?

Box specs: 1 ft^3 sealed each sub.... 4 ft^3 shared ported chamber.... This is going to be for daily ground poundin.

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[TaylorFade 10+ year member]

What makes you think the VVX is suited to a 4th? Do you know how big of a sealed section you're going to need to get them flat with a Qts of .65?

Here a hint... huge.

If you don't go with at least 2cf sealed each, it's going to be peaky as shit. But maybe that's what you're going for. I dunno.

And what part of aero vs. slot is confusing you? They're ports. Do what you're going to do anyway and just guess.

 

[murph 10+ year member]

At one cube sealed each you will be doing more of high end pounding. I don't know how big you trunk is but, make sure to keep some room for the subs. That is unless you made a trunk wall.

 

[ThatChevyGuy 5,000+ posts]

Polyfill works wonders for the sealed section. If you have a big trunk why not 2.5 sealed 5 ported? You could always try some funky ratios as well. Most of the time you will have to play around until you get it right. Personally I would go with the AB TNTs price vs performance

 

[rickymac21 10+ year member]

What makes you think the VVX is suited to a 4th? Do you know how big of a sealed section you're going to need to get them flat with a Qts of .65?
Here a hint... huge.

If you don't go with at least 2cf sealed each, it's going to be peaky as shit. But maybe that's what you're going for. I dunno.

And what part of aero vs. slot is confusing you? They're ports. Do what you're going to do anyway and just guess.

Ok ****. First of all I'm not quesing about anything. I've been building ported boxes for years. I have yet to even think about designing a bandpass till recently. Regardless, I've done the google searches and can't find any answer to my question. And apparently you don't know either. I would graph it but my winisd took a $hit and won't allow me to enter my own woofers anymore. So just stop being a douche bag and be helpful, or stay out of my thread.

 

[rickymac21 10+ year member]

Polyfill works wonders for the sealed section. If you have a big trunk why not 2.5 sealed 5 ported? You could always try some funky ratios as well. Most of the time you will have to play around until you get it right. Personally I would go with the AB TNTs price vs performance

I have a solid 10 cubes to play with in the trunk. I know before my winisd quit working , 2 15" tnt's in a 2:1 ratio (6:3 cu ft) had a pretty good curve dropping at 23 hz and 56 hz. So with the 12's (not being able to graph) I would imagine they would still do well in a ratio similar. But if 1 cube is too small per tnt, what would be more adequate ? 1.5 ft^3 each ? Then just have a slightly lower ratio to pick up a slightly wider bandwidth? So I could do 3 ft^3 sealed and 5.5-5.75 ft^3 ported tuned around 40 hz.

Does this seem more realistic than the origal post/design ?