tuning help

[regal8r 5,000+ posts]

im gonna be building a new box but i need help with port length...volume is 5.2675 after driver displacement only. i would like to tune to 33hz, port area is 3x14.5 with 2 ports, one on each side of the box. OD's of the box is 36x25.5x16...this will also be for 2 05 12" type r's and hifonics bx2005d in a 96 monte carlo...thx.

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[hofulstrof 10+ year member]

download winisd

35" vent length based on 5.2 cf but at that lenght each port will displace 1.0cf....

 

[regal8r 5,000+ posts]

i have winisd but dont know how to use it lol...im looking for about 5cf after all displacements...do u have any suggestions?

 

[hofulstrof 10+ year member]

either make the box larger,raise the tuneing or decreas the port area.

i would shoot for around 28 sq" of port per sub

 

[regal8r 5,000+ posts]

ok so that would be about 2"x14.5" ports...would that be enough port area for type r's??

 

[hofulstrof 10+ year member]

yes

 

[regal8r 5,000+ posts]

what would my volume come out to be after port displacement with 2" ports then?

 

[hofulstrof 10+ year member]

length will be 23"

to get a rough estimate of how much a slot port will displace use this formula

( (width+wood thickness)x hight x length)) /1728= displacemnt

(2+.75)x14.5x23"/1728

2.75x14.5x23/1728

=.5 cf displacement

 

[regal8r 5,000+ posts]

length will be 23"
to get a rough estimate of how much a slot port will displace use this formula

( (width+wood thickness)x hight x length)) /1728= displacemnt

(2+.75)x14.5x23"/1728

2.75x14.5x23/1728

=.5 cf displacement

what length, port length?? u said at the top that i would need 35" long for each port...

 

[hofulstrof 10+ year member]

yeah but you are now going with less port area so then the length will also be reduced

5.2cf@33hz with 2 ports with 29sq" of port (14.5x2) will have a vent length of 23 "

refined formula

( (width+wood thickness)x hight x port length)) /1728= displacemnt

 

[regal8r 5,000+ posts]

so each port should be 35" long then, correct?

 

[hofulstrof 10+ year member]

sorry i edited my post... look again

 

[regal8r 5,000+ posts]

i dont see an edit //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[hofulstrof 10+ year member]

post # 10

the part about your port length being shorter because you are going with less area?

 

[regal8r 5,000+ posts]

alright, i see it now....so each port will be 23" to get me a tuning of 33hz then???