Dual 12s box design

[sittinguy]

I plan to build a 4 cuft net box for 2 sundown u series 12's on 3500w rms tuned to 32 hz. Using triticums improved port area calculator it recommends 97sqin of port area where as sundown recommends 32sqin per sub. I can easily fit 97sqin of port area but my question is what is the benefit of having such large port area on such a small box?

[AaronT]

I'd personally go with Sundowns recommendation.

Smaller port area is "faster" and lends itself to better sound

 

Give this video a watch  

 

[AaronT]

By the way, this guy in video is a master in acoustics, he's very smart and knows the craft like no other

[Triticum Agricolam]

2 hours ago, AaronT said:

I'd personally go with Sundowns recommendation.

Smaller port area is "faster" and lends itself to better sound

 

Give this video a watch  

 

That is one of Pete’s best videos, I have nothing but agreement with everything he said. 

“Smaller port area is "faster" and lends itself to better sound”  - - This is 100% incorrect.  Pete said nothing to this effect in his video and whoever you heard that from has no understanding of the physics of ported enclosures. 

 

[Triticum Agricolam]

3 hours ago, sittinguy said:

I plan to build a 4 cuft net box for 2 sundown u series 12's on 3500w rms tuned to 32 hz. Using triticums improved port area calculator it recommends 97sqin of port area where as sundown recommends 32sqin per sub. I can easily fit 97sqin of port area but my question is what is the benefit of having such large port area on such a small box?

Sundown’s port area recommendation is based on the assumption you will be running RMS power. You are running more than that so more port area is probably a good idea. 

 

There really is no performance disadvantage to running more port area. Where problems can arise is when you increase port area you also have to increase port length to keep tuning the same and there definitely is such as thing as a port that is too long. When ports get really long you can start to have pipe resonance issues. For this reason I keep ports under 45” in total length.

 

In your case you probably aren’t going to be able to use a 90+ sq in port without it getting too long. My suggestion would be to use as much port area as you can while keeping port length reasonable.