box tuning

[RAM_Designs 5,000+ posts]

and everyone on roe says u use after port displacement (VB ) to tune it but how the hell do u have net displacement without a port yet lolz

Also, you don't have to have a set gross volume either. I can be set on a 3.5ft^3 box tuned to 32hz and I'll just use whatever port dimensions I want, find the length, then find the volume...add that to the 3.5ft^3 that I'm set on having for my sub, and just build my box based the 3.5ft^3 + port displacement.

 

[SicAudio 5,000+ posts]

I already answered that.
As for my evidence: http://74.125.47.132/search?q=cache:mriChcANXMIJ:www.clubknowledge.com/Car_Audio_FAQ/archives/4633.html+use+net+volume+to+determine+port+length&cd=4&hl=en&ct=clnk&gl=us

"We use Vb. Vb is the net box volume of airspace inside the box, after we subtract sub and port displacement values. "

"In all of these formulas to calculate port length, you're supposed to use the net internal volume."

It's also good to use common sense. If you think that you are supposed to use box volume before port displacement, then I can come up with a design that will yield negative box volume. How about a 1ft^3 box uned to 20hz with an 8" aeroport? It'll need to be 332" long, which as I'm sure you know will be more than 1ft^3 worth of displacement. A program cannot account for things like this, or what I mentioned before about variables that are involved with the port itself.

but it wouldnt be if you used a 2" port which is more realistic.

and also the people in that thread u posted said they use 12volts calculators doin git to find it the way 12volt says also agrees with me //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[SicAudio 5,000+ posts]

every possible software that everyone uses and every online calculator i can find all say the same thing net volume is after all ports and bracing ect it is the "useable airspace" and can not be used to tune the sub enclosure. it is an unknown. u dont have a net volume til after u have a port.

 

[wenn_du_weinst 10+ year member]

dude sic you have argued with 30 people now your wrong get over it

 

[RAM_Designs 5,000+ posts]

but it wouldnt be if you used a 2" port which is more realistic.

That doesn't matter. If I wanted to have a box like that, how would I do it? According to your logic, it's impossible.

and also the people in that thread u posted said they use 12volts calculators doin git to find it the way 12volt says also agrees with me //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The 12V calc isn't the issue at hand here, you're missing the point. The point is that the volume used in the calcs is net volume, after ALL displacements(this includes port displacement).

You're using gross volume(or close to it since you subtracted sub displacement). Even in the link you posted on roe as your "proof" had TommyK saying exactly what I'm saying. In case you missed it, I'll quote it for you.

"The easy way that I calculate up a NET enclosure is like this.

1) Figure out what net volume you want

2) Figure out the port size and length needed to tune it to what you want

3) Figure out the port displacement

4) Add 1&3 together

5) Design a box that has that much gross airspace"

 

[wenn_du_weinst 10+ year member]

well thanks everybody for clarifying it I would have been pissed if I had been designing boxes wrong for 10 years and would have had to talk to the guys who taught me

 

[Johnny Law.Lulz 5,000+ posts]

lol at this. Brought the CACO dweller out cuz you pissed him off.

 

[RAM_Designs 5,000+ posts]

every possible software that everyone uses and every online calculator i can find all say the same thing net volume is after all ports and bracing ect it is the "useable airspace" and can not be used to tune the sub enclosure. it is an unknown. u dont have a net volume til after u have a port.

Not true. I want my net volume to be 2ft^3. I plug in 2ft^3 and find out my port length. I add the port volume to my 2ft^3 in order to find out how big I need to make the box...that simple.

 

[RAM_Designs 5,000+ posts]

Face it sic, you made this thread thinking you were pwning some noobs at roe, when in fact you were wrong. You're generally a dick anyways, so I'm not really surprised that you came in here trying to come off as this holy dispenser of box tuning knowledge. You're like that in a lot of your posts, when you act like you know more than everyone and talk down to them...kinda caught up to you here, huh?

 

[SicAudio 5,000+ posts]

That doesn't matter. If I wanted to have a box like that, how would I do it? According to your logic, it's impossible.
external port //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The 12V calc isn't the issue at hand here, you're missing the point. The point is that the volume used in the calcs is net volume, after ALL displacements(this includes port displacement). the calculator doesnt know the port yet so if it doesnt how is still right? based on ur way of doing it?

You're using gross volume(or close to it since you subtracted sub displacement). how do you know the port volume without having 1 to account for in the calculator?

the calculator is set up to walk u thru it step by step in order of calculations and figuring box volume comes before figuring the port. so explain that ?

Even in the link you posted on roe as your "proof" had TommyK saying exactly what I'm saying. In case you missed it, I'll quote it for you.

"The easy way that I calculate up a NET enclosure is like this.

1) Figure out what net volume you want

2) Figure out the port size and length needed to tune it to what you want

3) Figure out the port displacement

4) Add 1&3 together

5) Design a box that has that much gross airspace"

now do that in order!

if a sub needs 2 cf ok i know my net is now 2cf

figure out what port i need and the length ect

then figure what it displaces

then add that to the net

i got gross box ect.

how exactly do u tune to an unkmown volume? thats the point i am asking to be clarified in simple english

and **** u wenn i didnt say **** in ur thread ****** so dont do it in mine.

 

[RAM_Designs 5,000+ posts]

now do that in order!if a sub needs 2 cf ok i know my net is now 2cf

figure out what port i need and the length ect

then figure what it displaces

then add that to the net

i got gross box ect.

how exactly do u tune to an unkmown volume? thats the point i am asking to be clarified in simple english

and **** u wenn i didnt say **** in ur thread ****** so dont do it in mine.

You're really bad at reading comprehension, aren't you? You just said the sub needs 2ft^3 net, which is after ALL displacements. THAT IS WHAT YOU USE TO FIND YOUR PORT LENGTH, IT'S WHAT YOU PLUG INTO THE CALCS FOR CHRIST'S SAKE.

 

[wenn_du_weinst 10+ year member]

lol at this. Brought the CACO dweller out cuz you pissed him off.

I'm on roe most the time now caco is getting to whiny for me

 

[Johnny Law.Lulz 5,000+ posts]

HAHA. It got whiney for me when the admin/mod staff turned into hipocrits (sp?)

 

[wenn_du_weinst 10+ year member]

I still don't know how you got banned and I only have one timed out infraction

don't remember why I think I told some one to kill them self

 

[RAM_Designs 5,000+ posts]

Also Sic, you just went against your own port tuning expertise when you answered my little conundrum with "external port." Better yet, answer me this: what's the internal box volume of a 3ft^3 box tuned to 35hz with a 6" internal aeroport, and one with an external 6" aeroport? Don't even take sub and bracing into consideration in this case, just plain and simple port question. If net volume didn't include port displacement, then you'd have to be restricted to using either internal or external ports only, since going one way or the other would change box volume after port displacement(or not change it).