d2jsp
Log InRegister
d2jsp Forums > Off-Topic > General Chat > Car Audio > Help Understanding Port Depth > Please Help
Add Reply New Topic New Poll
Member
Posts: 1
Joined: Jul 21 2017
Gold: 0.00
Jul 21 2017 04:06pm
Okay im building a box witch I have done before more than once so I know the basics and how to use a box design app to calculate the port but im still learning so say I want to build a 4th order bandpass box for one sub and when I figure the port on the app I use it says my port needs to be 4" wide 6" tall and 12" long to be tuned for 32hz the thing is I have a 4×6 hole through my rear seat that I want the port to stick through so my qushtion is if the port is supposed to be 12" deep in the box but I want it to stick out 6 inches instead of being flush with the box what do I half to do to the port to end up with the same tuning of 32Hz? I would really appreciate it if someone could help me out if what im asking makes no sence im sorry I don't know how else to explain it
Member
Posts: 42,384
Joined: Oct 23 2007
Gold: 2,848.72
Warn: 80%
Jul 21 2017 07:49pm
Welcome to jsp
Gz on 1St post
Member
Posts: 32,969
Joined: Mar 17 2005
Gold: 0.00
Jul 22 2017 11:19am
calculate for the lost air space in the 6 inches of wood you will be losing internally and then just cut the interior port length in half and extend it out 6 inches for the lost internal 6 inches.

unless you are willing to do extra work for something that is almost certainly just cosmetically different you can just put the port how the app told you to. its not going to make a real difference output wise by making the port stick into the cabin area.
Member
Posts: 45,974
Joined: Feb 5 2008
Gold: 1,055.90
Jul 24 2017 06:57am
Quote (Subwoofer @ Jul 22 2017 01:19pm)
calculate for the lost air space in the 6 inches of wood you will be losing internally and then just cut the interior port length in half and extend it out 6 inches for the lost internal 6 inches.

unless you are willing to do extra work for something that is almost certainly just cosmetically different you can just put the port how the app told you to. its not going to make a real difference output wise by making the port stick into the cabin area.


It definitely would though, output wise, less energy used when the seats aren't working against you it would be louder, there's a reason stripper pole makes u louder, when u aren't flexing the truck u waste less energy (might not be audibly louder but it would meter louder, talking a small margin of gain but gains are gains)

U don't want a 4th order bandpass tuned to 32 u should try 40 - 50 hz as the sealed section will help alot with low end response nine is tuned to 45 and gets down, though I would tune to like 40 or 42 if I rebuilt it ever

Tuning to 32 will dramatically reduce output and will give it super flat response

Also make sure u use about 70% of the recommended sealed section for your box and usually 2:1 ratio on the ported side to the sealed side, larger ported section yields bigger output but it will become more peaky

U can use ultimate car audio app on your phone to plot the ported section and play with ports and tuning, again I would strongly advise tuning in the 40s it will be a much better box, unless ur doing home audio then I don't want to get involved

This post was edited by TanKiE on Jul 24 2017 07:06am
Go Back To Car Audio Topic List
Add Reply New Topic New Poll