Audioque and RE box calculator QUESTIONS

[mlstrass 5,000+ posts]

make the port 21" long if you want to tune to 35Hz, but 38Hz will be fine with those subs in 8.5cubes net. I've built a few just like that for the SDC's and they pound the lows...

 

[Bass911 10+ year member]

make the port 21" long if you want to tune to 35Hz, but 38Hz will be fine with those subs in 8.5cubes net. I've built a few just like that for the SDC's and they pound the lows...

Check yo PM!

 

[mlstrass 5,000+ posts]

pm answered...

 

[fasfocus00 5,000+ posts]

Are you saying no to my drawing or no to it shouldn't be tuned lower?

no to being tuned lower

 

[newdude 10+ year member]

fasfocus I must be using same calculator as you that is what I am coming up with

 

[Blue Fury 10+ year member]

Sic, you really believe the RE calculator is designed JUST for RE subs because the guy said so?

Here: That guy obviously works with RE, so he knows what he's talking about. Thus, it must be true.

I am obviously myself, so I know what I'm talking about when I tell you about myself. I am 12 feet tall and weight 1000 lbs. Since I said that about me, it must be true to you.

See what I'm getting at? I want you to consider how it could be possible for this calculator to work only for RE subs. The only way is if there are factors included with every calculation. What could these factors be? Linear, logarithmic, or whatever, they would HAVE to influence the output of the sub. If they didn't, the calculator is wrong by percentage relating to each factor. If the factors do exist, they should be noted on the RE site with the description of each sub wouldn't they?

I really don't see how the calculator could only work for an RE sub. I need some convincing other than 'he said so' because I'll just tell you that I'm 12 feet tall again.

 

[s_c]

alright based on what you gave, according to RE you're at 8.545 cubes tuned to 33hz without sub displacement. I am using my calculator for this and am coming up with 9.597 cubes tuned to ~37hz before sub displacement. don't know what the deal is with the net displacement but as stated the tuning frequency is off by a few.

check the math for the box he stated it's not 9.597 cuft more like 8.92cuft this is with port displacement and the point 42 will be made up with the subs displacement so the box volume is closer to 8.5 cuft

outside dimension 49x 25.5 x 18 minus 1.5 from all sides to get 47.5w x 16.5hx 24L. this is the inside dimension if using 3/4 inch stock

port 8.25w x16.5h x i used 21L inch long just a guesstimate before tuning 16.5x9.75x21 multiply those to gather then divided by 1728 to get 1.9555cuft minus this from the box of a 10.88cuft box yields 8.92 cuft you must be using the out side as the inside dimensions lmao.and it yielding a bigger box like 9.597

here is the math i use to figure ports just encase you want to check the other calculators out this one does not use t/s speaks to calculate box if this gives any one a hint

Ported boxes

Letters used in formulas as follows

Av or area of vent or Port area=pie time radius squared of a 3 inch port which =7 x1 or just 7 for this formula do not use round port of like 3 and 4 inch it will throw off formula use the pie time radius of port to get those by 1 inch

vb or volume of box =cubic inches for this formula has to be cubic inches can be gotten from width time height times length can divide this by 1728 to get cubic feet for manufacture specks

lv equal length of vent in inches

fb equals tuning frequency

We use the formula above like so we do this first and write it down av(1.84time ten to the eight power )then hit equals and write it down

Next we take vb(lv+.823squae root of av ) take those to answers after written down and divide by each other and add it in the square root of this part like so .159 square root of answer = tuning frequency

General rules to ported boxes

The port must not be a ratio greater then a 9:1 area

Must not use more then plus or minus 20%of manufacture specks for their boxes of what they perform best in.

The port must be measure down the center line and a correction factor of .5 time h must be added in the h is from hxwxL of a port

fomula for area lxhxw/1728

 

[Blue Fury 10+ year member]

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[Bass911 10+ year member]

Yall thought it was over? Do this math for common chamber with port in the middle? Straight port, no L.

Top&Bottom- 49 x 24

Back- 49 x 16.5

Port- 18.375 x 16.5(x2)

Left&Right sides- 22.5 x 16.5(x2)

Front- 20.375 x 16.5(x2)

 

[s_c]

Yall thought it was over? Do this math for common chamber with port in the middle? Straight port, no L.
Top&Bottom- 49 x 24

Back- 49 x 16.5

Port- 18.375 x 16.5(x2)

Left&Right sides- 22.5 x 16.5(x2)

Front- 20.375 x 16.5(x2)

looks like 39.09 hertz to me. me my self does not like to tune high like in the 40+ region and that is very close to it. i like hitting the low notes in the 35 to about 18 hertz. i also do not use the extra volume for displacements some times you will get that one sub that just does not like the bigger boxes. put it this way you may have to rebuild if it sounds like cone fluttering crap cause you added in to much volume and a short port but this is how you got to learn it's trial and error to find out were you like it. if you need more help just say some thing.

 

[Bass911 10+ year member]

looks like 39.09 hertz to me. me my self does not like to tune high like in the 40+ region and that is very close to it. i like hitting the low notes in the 35 to about 18 hertz. i also do not use the extra volume for displacements some times you will get that one sub that just does not like the bigger boxes. put it this way you may have to rebuild if it sounds like cone fluttering crap cause you added in to much volume and a short port but this is how you got to learn it's trial and error to find out were you like it. if you need more help just say some thing.

That's how Audioque says it's supposed to be tuned and it will still hit the lows.

 

[s_c]

all i can say is if it does not sound right then do not leave them in it. that why i say there is a exception. you got two of the bad things i do not do in one box. now if your sub only has about 9 mm of x max i would tell you not to put it in that box most of the time subs with small x-max don't like big boxes. and the cone flutters and bats the voice coil around and sounds like crap. if the company is calling for it there is a reason might be that the box will make the sub spike a little higher and make the sub louder. like earlier all you can do is just trial and error till you get it right.

 

[SicAudio 5,000+ posts]

That is not the same with this slot port, your using 3 of the boxes walls to make up the port. It carries around the corner in this instance. If it ended greater then 8.25" away from the back wall then you account for the corner in the volume.

reread this and think again stupid u have contradicted proven math and urself about 6 times alone just in this thread just shut the fuc k up now lolz

 

[s_c]

reread this and think again stupid u have contradicted proven math and urself about 6 times alone just in this thread just shut the fuc k up now lolz

dude chill no need to get hostile over a stinking post. i think he is right on what he is saying for one he is suggesting to tune lower which is correct to do and secondly if you tune lower. you will have to add in the corner of and a plus .5 times 8.25 because of the fact air is moving in and out of the port so the port is further past were it stops no matter what. they talk about this at jl audio under tutorials. like he said it has to be a min of 8.25 from all side's including speakers cause this will make the port seem longer. that one is on rockfordfosgate.com subtitle of : "were to place your port" under the tab at top woofer box wizard. like so

http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php?p_faqid=26

it’s lv(eff) at link below

http://mobile.jlaudio.com/support_pages.php?page_id=165

 

[Bass911 10+ year member]

S_c check yo PM