Crunch Ground Pounder 12 box

You are so lucky to have a carpentry shop at your house! I just wish I had a garage!

 

Hey, liftedranger, a couple of questions.

I always thought the aero port typically raises tuning frequency. With that said, the port looks way to short for a tuning that low. Now I cannot tell the size of that box from pictures so I could be way wrong. So what is the box volume and how long is that vent?

I'm curious and I'm gonna do some research on those vents

By the way, you do awesome work, keep it up

 

That sounds about right, thank you

 

I assume that the 11-inch length does not include the flair. If your including the flair, the port is way to short. For 33Hz with a flair at both ends the port needs to be 15-1/2-inches long. As I suspected, flairing raises tuning frequency.

I copied this from the website http://www.subwoofer-builder.com and it states that

A flared port shares part of the air in the flare with the surrounding air, meaning that the port appears shorter. The generally accepted adjustment is to subtract half the flare radius from the physical length to obtain the effective length. If both ends of the port are flared, the adjustment is done for each flare

which means that your port is too short.

I'm gonna do some more research on those ports, I find some of the vent velocity characteristics interesting

 

It would seem to me that this type of vent would act somewhat as a venturi in a carburator. gathering the air at the boundary layer of the vents radius and accelerating it along with the air mass in the vent itself I would surely think would effect the tuning to a degree.