enclosure resonance

ok, so how do you know what frequency you want it to be tund to, isnt there a calculated frequency for the box? if so how do you calculate it?

thanks

Find the frequency to tune a vented box according to:

• the recommendations from the manufacturer for that particular sub
• your musical tastes, e.g. SQ or SPL?

In general terms, box tuning is calculated from two things:  box air volume and port volume.  Port volume is determined by port opening area X port length.  The application on this site figures port length for round ports.

I must tell you this right from the start:  building and tuning a vented box is not for the amateur.  By the time you understand exactly what you are doing you will no longer qualify as amateur status, which is the good part.  Here's where you should start.

• http://www.diysubwoofers.org/prt/

You will see actual calculations and theory here.  Then you can use this knowledge to better understand the port calculators that are available.  Here is one that provides graphs according to your input:

• http://www.mhsoft.nl/spk_calc.asp#ported

Other more advanced and more accurate methods would be to use one of some available box-building programs.  WinISD Pro is a popular one that a lot of people use.  Refer to the sticky subject above on this forum for links and as a starter guide.

thank you for the post, it has helped a lot.

with the musical tastes, wht is SQ and SPL?

and also, im using the Fb frequency to calculate the required port length that i need using the calculators on this website, so how can i know the port volume if it is opening x length?

thanks