Tuning question

[mazzasec 5,000+ posts]

Well I got this design for a box and I am going to a shop for them to build it. This is the design.

17"H x 42"W x 24"D, 8.174^3ft gross vol. Slot port, 15.5" x 5" x 15.92"Long@37Hz. After all displacement, 7.048^3ft net

What do I need to change if I want the tuning at 35?

And heres one more

17"H x 42"W x 22"D, 7.447^3ft gross box vol. Slot port, 15.5" x 4" x 22.3"long@32Hz

but i wanted a 5 inch port cause it looks cooler! so how to i accomodate that?

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[dman4486 5,000+ posts]

longer port

 

[mazzasec 5,000+ posts]

So what should it be to be tuned to 35?

 

[Immacomputer 10+ year member]

Any doubled up panels anywhere? All 3/4" MDF?

 

[dman4486 5,000+ posts]

if your after displacement volume is correct, then 14 inch port will be 35hz

 

[mazzasec 5,000+ posts]

Ya i am pretty sure its correct a JD at east cost enclosures did that design I am going to a shop to have the box built and im just printing out the design so what will this have to be to get 35?

15.5" x 5" x 15.92"Long@37Hz

 

[dman4486 5,000+ posts]

Ya i am pretty sure its correct a JD at east cost enclosures did that design I am going to a shop to have the box built and im just printing out the design so what will this have to be to get 35?
15.5" x 5" x 15.92"Long@37Hz

this is the before displacement number...i always use after displacement volume for my port calculations which is 15.5 x 5 x 14 for ~35hz

 

[dvrmstrng 5,000+ posts]

ought to cost you a good 300+ dollars to have that made....versus probably under $100 to DIY

 

[mazzasec 5,000+ posts]

Ya well I dont have any wood and material and have NEVER built a box in my life. Also I have had my subs for about 2 weeks just sitting in my room and im gettin impatient! the shop wanted 250

 

[dman4486 5,000+ posts]

have you ever played with lego's?

 

[mazzasec 5,000+ posts]

ya you ever try to play with legos without legos?

 

[dman4486 5,000+ posts]

it's like that except u have to cut holes and use glue/screws...very simple and a great way to learn

the materials are relatively cheap and highly available

 

[dman4486 5,000+ posts]

ya you ever try to play with legos without legos?

haha...yes:crap:

 

[Immacomputer 10+ year member]

The net volume he gave you is incorrect. The net volume of that enclosure with a 14" long port is about 6.85 cubes before sub displacement. That gives a tuning frequency of about 33-35hz depending on whether or not bracing is used and if there are any doubled panels (which you ignored to mention).

Either way, his calculations were incorrect.