My ported box design

[shendrix777 10+ year member]

I have an 89 ford ranger supercab and im putting 2-10.1 infinity perfects in it. Due to the lack of space im designing something creative. Don't worry about dimensions I have it measured out to be almost exactly the rated 1.0 ft^3 I just need to know if the design will work. I have never built a ported box before so I am going off research alone, any input and design ideas similar to this will be helpful. Sorry that my drawing sucks.

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[Mr Cabinetry 10+ year member]

I have an 89 ford ranger supercab and im putting 2-10.1 infinity perfects in it. Due to the lack of space im designing something creative. Don't worry about dimensions I have it measured out to be almost exactly the rated 1.0 ft^3 I just need to know if the design will work. I have never built a ported box before so I am going off research alone, any input and design ideas similar to this will be helpful. Sorry that my drawing sucks.

Well, if you calculated the total volume @ 1.0 cu.ft. for what you have your already boned since your using 2 subs ya need 2.0 cu.ft.

Next, your design shows only 1 round port for 2 subs, your boned in terms of port noise since your doing the subwoofers common chamber ported and if you use the spec's provided per Infinity's pdf enclosure, the enclosure is going to sound like azz because the port tuning is going to be way off.

The design concept is good but you will need increase the enclosure size to bring the volume inline with the spec's and you will also have to re-calculate for multiple ports in a common chamber if you want to maintain the tuning frequency spec'd as well.

 

[shendrix777 10+ year member]

Sorry I made a mistake it is 2.0 ft^3, 1.0 per/sub. But I'm not sure what you mean in reference to the ports. I will need 2 ports for 2 subs? If you could explain that I would be very greatful.

 

[PowerNaudio 10+ year member]

since you have 2 10" subs 1 4" port even though it will get you the tuning you need, is too small in diameter to support the amount of air being forced trough it, and the end result will equal port noise. so youll need to increase the amount of ports used to bring port noise down to none audible. so to achive that youll need at least 2 4" ports per sub.

 

[shendrix777 10+ year member]

In the sub specs it recommends a 3in port being 10.4 inches long. If I use a 4 in port what would be an ideal length?

 

[xluben 10+ year member]

In the sub specs it recommends a 3in port being 10.4 inches long. If I use a 4 in port what would be an ideal length?

do you realize you need to account for port and sub displacement when figuring net volume?

so for that 3" port and a 10" sub you could assume around 0.12ft^3 of displacement.

but that recommended port is only 7in^2 of port area and tunes the box to 38Hz.

port is too small, and tuned too high.

i'd go for at least two four inch ports (for both subs combined) and tune to 35Hz or lower if possible.

assuming a decent amount of driver displacement and the correct port displacement:

to get a 2ft^3 box tuned to 32Hz you need:

2.65ft^3 of internal volume (before displacement)

two, 4" diameter ports, each 30" long

just an example, but i hope that helps!

 

[shendrix777 10+ year member]

Thank you that makes alot more sense now. My box is 2.3 ft^3 if i still added the port would there be any possible ways to make the design work.

 

[xluben 10+ year member]

Thank you that makes alot more sense now. My box is 2.3 ft^3 if i still added the port would there be any possible ways to make the design work.

hmm, you're really pushing it.

making a too small ported box will have a very peaked response, and probably not sound good with most music.

1ft^3 seems small to begin with, sometimes manufacturer recommendations aren't always best. if you had t/s parameters you could model it with winisd or other software to get a better idea of how small is 'too small'

maybe just try a sealed box?

or figure out a way to get a little more space?

 

[Pyro_By_Nature 5,000+ posts]

I'm not even going to try and read all the notes.Just go sealed.

BTW: You don't need 2 4" ports for 1 10" sub.

 

[xluben 10+ year member]

I'm not even going to try and read all the notes.Just go sealed.
BTW: You don't need 2 4" ports for 1 10" sub.

i was suggesting 2 4" ports for 2 10" subs.

 

[Pyro_By_Nature 5,000+ posts]

i was suggesting 2 4" ports for 2 10" subs.

No no no no lol, I was referring to powernaudio.

 

[PowerNaudio 10+ year member]

I'm not even going to try and read all the notes.Just go sealed.
BTW: You don't need 2 4" ports for 1 10" sub.

you dont need 2 4" per 10" sub. but 2 4" per sub will most likely keep the box port noise free.

 

[Mr Cabinetry 10+ year member]

To the OP,

Just bag using round ports and use one larger slot port to handle the the increased air pressure that two subwoofers common chamber will need to move to reduce the chance of port noise occurring.

In order for you to properly calculate the correct net volume plus subwoofer displacement for your design merely subtract the volume being displaced by the port per Inifinity's spec'd ported design.

Then, use whatever design program you like to re-design the enclosure to properly calculate for a single slot port to port tuning you want, but more important, to provide enough port area so you don't get any port noise based on the amount of power you intend to push the subs with.

 

[shendrix777 10+ year member]

Thanks for all the help guys I went with the sealed enclosure to be on the safe side. Ill get some pics on here when I get to my comp.