Port area arguement

[Papermaker85 5,000+ posts]

no, it means the calc is garbage lmao. Even according to winisd the port area recommended was way closer to what i experimented with rather than that stupid calc that does not factor in TS specs nor power.

I don't know what you don't understand about displacement and tuning frequency.

Look at the Excursion graph when you plot your driver take that number for the maximum Excursion and put it in the calculator like I said the calculator is older and takes an account for quite a bit more SD then the typical drivers so it's off a little bit.

Even if you read when win ISD you'll see that only displacement and tuning frequency give you vent velocity

 

[Papermaker85 5,000+ posts]

Car Audio - Vent Air Speed Formula and Calculator

 

[tymoto21 10+ year member]

That calc is very off

For 4 18's it recommends 700sq"

I don't think I've ever seen a build with 700sq" of port

 

[hispls 5,000+ posts]

Could it also damage the sub?

If your woofer is displacing more air than the volume of the port, yes,. At that point it becomes a very leaky sealed box and you basically may as well just have it on the passenger seat with no box whatsoever. That said I suspect you'd be hard pressed to mechanically break Zv5 with the big roll surround.

For practical purposes you cannot have too much port area but too little causes port noise, inefficiency, and can lead to loss of control over the cone (possible damage).