BTL box

[treylittlefield 0]

i have 2 12inch BTL's and was wonderin what the best cuft and hz would sound the best. i listen to lots of rap and like my music low and loud. also how much sq in of port should i have?? should it be a port for each speaker or can it just be a big port in the middle?? i have a drawing that i like but it isnt tuned right. i'll try to get a pic up of it. if someone would like to email me or pm me my email is [email protected]. any help would greatly be apreciated. also someone was tryin to tell me that btl's are not good daily drivers that they wouldnt sound very good...any advice or opinions would be greatly appreciated. thanks

Edited July 7, 2009 by trey1

[mbarber25 29]

i can help you out a bit. first off idk if you've came across this thread but here you go

it can answer your question on how many sq inches of port and maybe a couple others.

30hz-34hz would probably work i'm guessing but i could be wrong. someone will correct me if so.

but for the daily driving part... there's probably the same, if not more, amount of people who use btl's in daily driving setups. (MUST CHOOSE DAILY OPTION BTW)

the rest is for the more knowledgable people.. i just figured i'd try to help..

Edited July 7, 2009 by mbarber25

[treylittlefield 0]

i can help you out a bit. first off idk if you've came across this thread but here you go

it can answer your question on how many sq inches of port and maybe a couple others.

30hz-34hz would probably work i'm guessing but i could be wrong. someone will correct me if so.

but for the daily driving part... there's probably the same, if not more, amount of people who use btl's in daily driving setups. (MUST CHOOSE DAILY OPTION BTW)

the rest is for the more knowledgable people.. i just figured i'd try to help..

yeah i read that link before but thanks. lol i was hopin somone would explain the whole sq in of port deal..like what number to use cause i'm sure it efffects the tuning...i just need to be steered in the right direction. i also heard that u shouldnt run these subs through any box building program cause it makes em sound like shit. cause the box above has like 23 in of port. and it needs at least 30 in. would someone please fix this box or show me another one cause i kno ppl on here know how to make these things come alive and it all starts wit the box

[KU40 173]

Start with the recommended volume that the manufacturer suggests. Then I'd suggest giving each sub about 30 sq. inches of port, or 60 sq. inches total. You can make it two ports or one, doesn't really matter. From there the tuning depends entirely on the length of the port. I think around 32 hz should do fine.

You can put them in a box program to get port dimensions. Just don't believe the SPL graphs.

[BigCProductions99 21]

Well, The Area Of The Port Doesn't Effect The Tuning, The Length And Width Does.

Good Rule Of Thumb Is 12-16 Square Inches Per Cubic Foot Of Enclosure Volume.

It's Funny How I Can Stick My Dad's 1.25 Cube Ported Box With A Icon 10" ALL The Way In My Port, And Still Have Room. (Tuned To 31hz, Btw.) I've Got To Post A Pic Of That When I Get My New Camera.

Edited July 7, 2009 by BigCProductions99

[KU40 173]

Actually, it's the area of the port. If you have a slot port that's 10" x 5", how would the calculator know if the 10" or 5" is the width?

[treylittlefield 0]

Actually, it's the area of the port. If you have a slot port that's 10" x 5", how would the calculator know if the 10" or 5" is the width?

correct me if im wrong but it doesnt matter does it??

[treylittlefield 0]

well i understand a little better now but the box above is a little big. it has 16.2 sq in of port

[KU40 173]

Actually, it's the area of the port. If you have a slot port that's 10" x 5", how would the calculator know if the 10" or 5" is the width?

correct me if im wrong but it doesnt matter does it??

No, it doesn't. But it just seemed like in BigC's post he just said that the width of the port mattered, not the height. Unless I misread. But the port area is what matters, because how do you know which dimension is the width? What happens if you turn the box on its side? Does the other dimension become the width? Unless he's talking about round ports, in which case yes the width of the round port is what matters, but that's because the width is directly correlated with the area of the port opening since it's a circle.

[KU40 173]

well i understand a little better now but the box above is a little big. it has 16.2 sq in of port

Well if you increase the port area to the correct size, the port will also need to be longer. Those two things make the port eat up more volume inside the box, which lowers the space that the subs use. After you subtract the new port displacement, the internal volume may be correct for the subs. You'll just have to figure out the port and go from there.

[BigCProductions99 21]

..That Wasn't My Intention, Height And Internal Length Play A Big Damn Part In Tuning Frequency.

"Well, The Area Of The Port Doesn't Effect The Tuning, The Length And Width Does." <-- You Can Have The Same Tuning With A Different Amount Of Area, That's What I Was Trying To Say.

Edited July 8, 2009 by BigCProductions99