DIY Sub question (1 Viewer)

[Nick L]

I am going to build my first HT sub. I would like to build one with one 12" driver, probably the adire audio shiva. I am going to build a box that is ported but do not know how to tune the ports? Can anyone point me to a chart or something that shows how long and wide a port has to be to get a certain frequency for the port?

Any help is much appreciated.

Nick L

 

[Dave Poehlman]

Can anyone point me to a chart or something that shows how long and wide a port has to be to get a certain frequency for the port?

I'm sure there's a formula someplace.. but, I usually use the online java calculator at http://www.linearteam.dk. Just go to the ISD Online section and choose vent calculator.

 

[Scott Page]

Nick,

Download the LspCAD software from the Adire website. It's free but only works with Adire products. Perfect for your needs. You plug in the parameters and it will do the calculation on port size and length for a given tune. Enter the tuning freq, then the port size you want to use and it will give you the port length.

Of couse you will want to set some of the other parameters first like box size. Yes, it works for sonotube designs to. Just pick box relex for the type.

You can download a manual somewhere for LspCAD too.