Prefabbed ported enclosures

[victor's gt]

With a prefabbed ported enclosure, when the box is advertised as having a specific tuning frequency, it is my understanding that the vent is sized in relation to the enclosure's air space (regardless of the subwoofer used) to get the "tuned frequency", correct?

Doesn't the tuning frequency change once you add your subwoofer(s) to the box which displace some of the overall air space?

[Ţĥıπģ₣ıѕђ]

It will, but usually the difference between sub displacements will be somewhat close. Worst case, the tuning freq will change a bit.

[victor's gt]

Originally Posted by Ţĥıπģ₣ıѕђ

It will, but usually the difference between sub displacements will be somewhat close. Worst case, the tuning freq will change a bit.

Well let's just take this as an example...

An IDQ12 displaces .05 ft^3

and

A RF Power 12 displaces .151 ft^3

I would say that is quite a difference, no? Use two of them and the difference is that much more.

[Ţĥıπģ₣ıѕђ]

This was the question.

Originally Posted by victor's gt

Doesn't the tuning frequency change once you add your subwoofer(s) to the box which displace some of the overall air space?

I gave the answer. YES, a woofer with larger displacement will change the turning freq.


The math of speaker displacement is not relevant to the question.

And yes, that extra .1 cuft matters, and is enough to be a factor, but once again, that was not the question.

[nitro70044]

unless you build the correct ported enclosure you would be better of with a sealed box.

[sqshoestring]

Best way is to get winISD and play with it. I don't think it will change that much, unless the box is tiny and thus the displacement change is a significant percentage of volume.

Really you have to build the box you want to get what you want. Premade you take what it is or try to fit a particular sub to it. Bought ones are always too small for me I want it low.

[T3mpest]

less than a tenth of cube isn't going to change your tuning in any meaningful way. Especially not since your putting it in a car that will do a heck of a lot more than a 1hz adjustment will to overall frequency response vs what winisd predicts. Hell, as soon as you turn it up you get more non-linearities to worry about that a 1hz difference in tuning. Basically, it really won't change it enough to care...

[victor's gt]

Although not a "prefabbed" enclosure....RE Audio does not take into account subwoofer displacement when using their calculator....

Does this mean that the enclosure calculator is not a good tool to use?