Calculating Port Length

[mdwerner6942]

Ok, I have read through a number of you guys' post, and I have exhausted all those, and still can't find a proper website or program to help calculate perfect/close tuning. Can someone direct me to a place that will calculate length of port for slot ports, and 0 common wall ports.

Any help is greatly appreciated.

Torres calculator will do it, when you choose 0 common walls it will basically not apply the end correction for slot ports with common walls but Torres have port displacement calculation errors so...

Your best bet is to have an accurate estimate of your net volume which can be had using Sketchup and an accurate number for driver displacement and the applying this (or maybe similar equations like the one Triticum Agricolam have linked):

Av is the cross-sectional area of the port (in square inches)

Lv is the length of the port (in inches)

Vb is the enlcosure's net volume (in cubic inches).

It will calculate the tuning for a port with a flanged end and a free end which is the normal situation if not doing a port with common walls.

If somehow this still doesn't get you close enough (and normally equations will only get you close) I would recommend doing a removable port and doing an impedance plot, keep changing the length of the port until you zero in your desired tuning, this will be the safest method, be reminded that temperature can play a role on tuning so likely in a cold night you will have a slightly different tuning than in hot day.

port aero 6" both flared just under 10" inside just under 8", just seen these plastic 8" items reference fiber ones but these are plastic.

torres has that on the bottom believe, again 8" port tuning that or 6" precision port site under tools, http://www.cemetube.com/standard.shtml

http://www.psp-inc.com/tools.html