small port area for a big box

[Beatin' 10+ year member]

Is there a moment in which the port area no longer matters if the box is very large?

I mess around with WinISD and tuning a box to 25hz for example would have the port be like 56 inches with around 15sq inches of port area.

Is there a limit where the port area for large boxes can be small as to not affect output yet keep the port as short as possible?

For example, if the box is big enough, could you get away with 7sq inches of port area rather than 14? I mean it's all relative to the subs cone area so there should be a limit to how much port area is actually necessary given the box size. I'm just wondering if the port area can be kept small to have the port length short enough.

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[azimuth 5,000+ posts]

You will get port noise if you go too small. Tuning that low will give you large overall box sizes due to port displacement. Maybe with the right sub and a 4th order bandpass you could do low tunings. Not easy to make it musical, but not impossible either.

 

[moneypit]

I think there is formula to figure port air speed. I wouldnt even know where to start with that info though.

 

[TaylorFade 10+ year member]

The lower you tune, the less port area you can "get away" with (usually).

Besides, 7sq in per cube isn't *that* bad if you're using aeros.

 

[BlactimusCrime 10+ year member]

Agree with T-Fade, if youre worried about overall box size and trying to minimize port volume, use aeros

 

[Side Show 10+ year member]

is it possible to have a small ported box for say a 12"sub, and an adjustable port to seal the box? and change the sub but use the same box? (dam that's confusing) so I can have a 12"ported system and be able to put a different 12"sub in and change to port for a sealed port making the box sealed?

 

[azimuth 5,000+ posts]

Yes. Problem is.....some subs are built for ported applications, some for sealed. Not to say they won't work in both. You could do small ported tuned high for numbers and plug the port and have a large sealed box for music. Aeros and expandable plugs could work. Whatever way you do it, it needs to be sealed fairly tight or it will whistle like a Frenchman.