Different length aeros?

[KHARPS 10+ year member]

Why couldn't it be simple???

ex: (15'' + 18'') / 2 = 16.5''......if only it worked that way.

 

[Immacomputer 10+ year member]

You have to think about it conceptually and not mathematically. Math helps explain physics but you shouldn't try to use it to break physics haha.

The concept here is that all things with mass will oscillate at a certain frequency. Air has mass and exists inside the tube of a port. Since the only thing that varies from one port to another is the amount of air in the port, it's safe to say that the one port holds more mass of air than the other. If two objects are equal everywhere except for mass, the object with the higher mass will oscillate at a lower frequency. In this case, that would be the longer tube.

If somebody had an enclosure with dual passive radiators, they could test this idea by cutting the mass of one in half and seeing where each one of them had peak movement. Those results would quickly tell if it was a correct assumption or not.

 

[KHARPS 10+ year member]

I understand what you're saying and the physics behind it. I'll just use both at 15'' and hope it sounds good daily. If not, I'll build a second enclosure with a slot port....which will take up more volume and bring it down to 1.25ft^3, which is what Fi recommends for the 10'' BL anyways. I just wanted to build one bigger than recommended to see if it will be more efficient and thus get louder.