too much port area?

[ehall8702]

have sum 10" sonotube sitting here and rather would use it vs buy more stuff. Have a Avatar stu 1246 going to be powered by a JP23 v2 @ .5 ohms. The sub specs want just under 2 cubes and wants 30in port area at 35hz. i want to be tuned lower, like 31,32 hz, just like the lower music, just a preference. Triticums port calculator says optimal is 55in port area at 31 and 2 cubes with 3k power. Ive read a lot of guy running bigger boxes with these with great results. wondering about 2.25 - 2.5 cubes and sonotube ( i build slots alot but wanna try a round port this time around). 10 sonotube gives me 78.50 cuin port area , is this too much port area ? Will i lose cone control and bottom out at this power level? If that is too much i will end up having to buy a big ass port, then the question is what size? Think 8" is 50 cuiin buut never been real sure on how to measure an aero port properly, would i better with 2 6" aeros? 

[Joe X]

The correct port area is what the manufacturer tells you, the port area for 35Hz will be the same as for 31,32 or whatever you pick in the lower 30s. If you are doing way more power or your box is way off the size the manufacturer tells you then you need modeling software to get port area right but otherwise follow the manufacturer suggestion, that tritricum calculator is either wrong or you are not using it right, I do not recommend using any calculators, use modeling software.

 

Use 30-35 square inches of port area, no more or you are going to get a ridiculously long port that is going to make the box gigantic and your port will suffer quarter wave resonances and inefficiency due to the excessive length.

[ehall8702]

I've used his calculator over a dozen times , with great results. I wasnt saying it would be different per tuning. But you as well as I know manufacturers recommendations are not always the most optimal, just useable. Like a xfl 12 wants to be in 2 cubes with 1000rms, but after half a dozen boxes , it sounded the best in 2.5 cubes with WAAY more port area than recommended.  Just trying to narrow this down a bit instead of having to build so many boxes to find what works best. As far as port area I'm asking how much is too much? Manufacturer wants 30ish, triticums calculator says 55 is optimal, just wondering how bad 78 would be just bc I have a few lengths of sonotube sitting here.

[Joe X]

If you use a net volume of 2 cubic feet net and  a 10 port it would need to be 96" long to be tuned to 32 hz. Regardless of if it will work or not how is it going to fit that and how is going to look, just by looking at that you can see that using the 10" pipe is not going to work very well.

[ehall8702]

Yeah was going to go bigger volume also, get your point tho be too long to get down where I want to be tuned at. Just gonna leave it alone till I have sum extra wood and just try sum other shit out. Gonna go with 2.5 cubes and an 8" I think, haven't sat down and messed with specific numbers yet.