for are expert enclosures plz NEED INFO ON A BOX

[SQBubble]

I need to know what tuning and how much cu.ft is this box:
all in inches

27.5 width
18 depth
17.5 height


the port size is 4x15.5
the port length is 13.5, there is only 1wood for the port.. no labyrinth or anything like that...


thx alot

[j3bus2k3]

IF those dimensions are your internals, your volume before DRIVER displacement is 4.55ft^3 and IF thats correct, your tuning is ~43hz. Thats using a formula off of JL's site and mind you there could be error on my part.

[SQBubble]

IF those dimensions are your externals, your volume before DRIVER displacement is 4.55ft^3 and IF thats correct, your tuning is ~43hz. Thats using a formula off of JL's site and mind you there could be error on my part.

woow I really doudt its 4.33, it isnt really big....
but thx can u tell me were on jl's site?

[j3bus2k3]

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

I made a typo, I figured those numbers were internals...I edited my original post to reflect that. But also too, you dont have much of a port to displace much volume....

[SQBubble]

But also too, you dont have much of a port to displace much volume....

wut does that mean, it could harm sub? and btw its for 1 15"

[j3bus2k3]

Higher tuned boxes have a shorter port length and in turn just dont displace a whole lot of space in the box. Its not going to harm the sub at all. Just a geometry thing...4.5ft^3 wouldnt be that far off for a 15 especially tuned that high...

[SQBubble]

cuz the guy that made me the box told me its a 3cu.ft tuned @32hz? but I just saw inside the box and it really dindt seem like it, (tuning)but it looks like a 3cu.ft

[SQBubble]

and I need to know wut tuning it is... cuz I realized the sub goes low.. but it seemed weird in the low notess...

[j3bus2k3]

Did someone on here design it? Just to clarify, are those numbers you gave in the original post external measurments? Tuned to 43hz would be the reason why it sounds "wierd" on the low notes...

[j3bus2k3]

Just for Shits and giggles I did it figuring those were externals...I got a volume before driver displacment of ~3.5ft^3 and tuning came out to be ~49hz....

This port length measurment you listed, is this the physical port length, or the effective port length? there's a major difference....

[SQBubble]

Did someone on here design it? Just to clarify, are those numbers you gave in the original post external measurments? Tuned to 43hz would be the reason why it sounds "wierd" on the low notes...

no its not someone over here.. and yes its the external, i just measured it...
fawkk, i told him to tune it around 30hz!! i guess hes a ******* and i learned my lesson, I aint gonna let anyone make anything for me when it comes to car audio, imma build my own box now, fawk those people, they dont care shyt ....

[SQBubble]

Just for Shits and giggles I did it figuring those were externals...I got a volume before driver displacment of ~3.5ft^3 and tuning came out to be ~49hz....

This port length measurment you listed, is this the physical port length, or the effective port length? there's a major difference....

well I measured the piece of wood inside the box!!

[SQBubble]

49hzzzzz , no wonderrr, it was freakin loud on the highs, like FREAKIN loud

[j3bus2k3]

no no no...the piece inside the box is just a derivative measurment of the port lentgh. The actual and effective port length is much different. Being a 4" wide port, your effective length should be in the neighborhood of...20"s...I think?

EDIT: Redid the math with a ballpark number of 20.5" for port length and its still 42hz...

[SQBubble]

ohh okk, so basically its around3.5 tuned @around 42hz!!

but when I play loww notes with that box, does it harm the sub? like 25-30hertzesss