Vent length question

[DAMIC]

I am just curious, maybe someone already asked the question, but I don't know how to search (key word).

Considering bass reflex type of enclosure, dezired tuning frequency, beside all factors is dependent by the length of the vent. For example, volume of the box is 0,9 ft3 (about 25 l) vent tube is on the outside cut as usually, under angle of 90 degrees but inside the box, the other end is cut under angle. So, looking from the side the trapezoid shape is obtained. Diameter of the tube is 2 inch, upper tube length is 2.3 inch what corresponds to dezired tuning frequency of 50 Hz and other longer length is 4.42 inch corresponding to tuning frequency of 40 Hz.

Well, I am wondering, what should be the final tuning frequency of the enclosure, 40Hz, 50Hz, something in the middle, or should maybe the tuning frequency be wider than usually (spread between 40 and 50Hz).

Thank's in advance.

[soongsc]

It really depends on what driver you are using and what its resonant frequency is.

[Tyimo]

Hi!

Diameter of the tube is 2 inch, upper tube length is 2.3 inch what corresponds to dezired tuning frequency of 50 Hz and other longer length is 4.42 inch corresponding to tuning frequency of 40 Hz.

You have to calculate the tube's air volume and than you can model and calculate a "normal" vent tube with the same volume of air you found.
Another way: just calculate with the avarage tube lenght.


Greets:

Tyimo

[sreten]

Hi,

The tube will operate as though it is slightly longer than
the shortest length, its not a good shape for good airflow.

/sreten.

[DAMIC]

Thank you very much for your replies.

Kind regards,