PVC / round port question

[blazeplacid 10+ year member]

Im building a 2.5 cube box tuned to 34hz.

A single 4" round port needs to be just a little over 9.5"

If I want two 4" ports do I just make each port 4.75" long?

Will this cause port noise?

Just a thought I had today and wanted to see if anyone had any insight.

Click to read more...

 

[bhsdriller 10+ year member]

no, that's not how it works....each one would need to be 20" for 34hz tuning according to psp-inc.com

Messing with their calculator if you had each one at 4.75" it would be tuned at like 56hz

 

[blazeplacid 10+ year member]

yeah I figured that was to easy

 

[SacTownBully84 10+ year member]

less port area = more port noise/broad bandwidth

more port area = less port noise/narrow bandwidth

in all reality tho u wont notice it unless its a wall behind ur seats lol....ive used straight pvc b4 and ive never noticed any difference...but ive only built trunks

 

[blazeplacid 10+ year member]

the seats dont fold down in my car so the trunk it almost like a wall.

there is a pass through but I couldn't hear any port noise if there was any.

Im gonna do a single 4" for simplicity

 

[BIGJEFF64 10+ year member]

no, that's not how it works....each one would need to be 20" for 34hz tuning according to psp-inc.com
Messing with their calculator if you had each one at 4.75" it would be tuned at like 56hz

so for instance lets say i have 4 8" subs and im using 4 4" aero ports its tellin me i need 52.3647" of port length to be tuned to 35 hz so if each aero is 13.09" long ill acheive that? btw that is in a 2cu ft box

 

[Fiendstolemyamp 10+ year member]

so for instance lets say i have 4 8" subs and im using 4 4" aero ports its tellin me i need 52.3647" of port length to be tuned to 35 hz so if each aero is 13.09" long ill acheive that? btw that is in a 2cu ft box

No, that is not correct. It's 52''+ each.

 

[bhsdriller 10+ year member]

so for instance lets say i have 4 8" subs and im using 4 4" aero ports its tellin me i need 52.3647" of port length to be tuned to 35 hz so if each aero is 13.09" long ill acheive that? btw that is in a 2cu ft box

you didn't say how big the box was, but the calculator on their site tell you how long each port needs to be. So if it says 52.36" that means that's how long each one needs to be

aero ports can be hard to use on smaller boxes for that reason, really long ports to get the tuning down. 4 4" ports seems too much for 4 8's?....50" of port, how big is your box?

 

[BIGJEFF64 10+ year member]

It was a scenario my box is 1 cube per sub so I think 4.2 gross with 4 4" aero ports it's an spl setup with 4 8's