PYRAMID WX85 8"

[Zeph 10+ year member]

cool, you even gave me the dimensions //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

pssh, this sub > re xxx 12 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

or to make it sound more like a person who would say that

tis sub r teh bettar re xxx 12 inch...lol

 

[Zeph 10+ year member]

by the way,

does 1.3 ft^3 tuned to 39 Hz

include the port and sub displacement allready?

 

[supa_c 5,000+ posts]

knowing Jmac and BBP6 yes it prob does

 

[Zeph 10+ year member]

the way he worded it kinda confused me maybe im reading it wrong by reading what he posts, thats what i picture..

 

[Zeph 10+ year member]

i mean, the way jmac wrote it down confuses me

is it like the normal L*W? because if it is, wheres this 23 comin from?

 

[Zeph 10+ year member]

ahhh i get it now.. i r teh stupid.

the 23 comes from the front board being 21.5, but add .75*2 accounting for the two side peices, and you get 23... ta daa, i solved my own thread.. lol

 

[Zeph 10+ year member]

oh btw jmac, does the port length you came up with count the .75 since its mounted on the box? or its without .75?

 

[Zeph 10+ year member]

wow, thanks so much, it woulda took me an hour to figure out all the calculations

thanks much

a round of applaud for Jmac

//content.invisioncic.com/y282845/emoticons/handclap.gif.0c301076f534e244f0460706894f19e0.gif

 

[Zeph 10+ year member]

hmm, i drew out all the plans on to the 3/4 mdf i got, and the port seems pretty small for 39hz?

thats a rough idea what it would look..

that port in the drawing is 2x1 internal area..which= 3 that jmac said?

 

[jellyfish420 10+ year member]

the port is bigger than that its 7"x3"

 

[Acidburn 5,000+ posts]

2x1 = 2.........

 

[jellyfish420 10+ year member]

build it like jmac says. it'll all turn out in the end, and its not just the size of the port, its a combination of area and length that determines freq.

 

[Zeph 10+ year member]

hmm? yall lost me

the the port is 7.5 long, and 3 inch surface area so wouldent thatmake the surface area 2 by 1.5?

 

[jellyfish420 10+ year member]

i got 3"x2.5" by 7.5"long. i'm pretty sure thats right, i used BBP6

 

[Zeph 10+ year member]

3x2.5" um wouldent take make the area greater than 3? i mean

i read jl audios thing on calculating Av...and now im confused..

they say

"the cross-sectional area "found by multiplying h and w" should be the same as that prediscribed for a round port. for example if our design calls for a 4'' diameter port, our ducts cross-sectional area should be 12.57

where do they get 12.57 from 4? ...this may be stupid but im really tired right now and i just cant understand it..