dual swr-1022d ported enclosure

[jeremyblevins 10+ year member]

Hello everyone,

i plan on building a ported enclosure with an internal volume of 1.24 cu. ft. for each sub with a 3'' precision port at 11'' long on each side. Are these good dimensions for these subs? and also are binding posts a good option the kind you drill a hole then tap it into the box?

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[RAM_Designs 5,000+ posts]

Binding posts are fine, as are the usual terminal cups that you see everywhere. Is the 1.24ft^3 you spoke of after sub and post displacement?

 

[jeremyblevins 10+ year member]

Binding posts are fine, as are the usual terminal cups that you see everywhere. Is the 1.24ft^3 you spoke of after sub and post displacement?

Yes all displacements accounted for, well besides speaker wire.

 

[RAM_Designs 5,000+ posts]

So you're shooting for somewhere in the 35-36hz range for tuning then?

 

[jeremyblevins 10+ year member]

33 hz I think it was.

 

[RAM_Designs 5,000+ posts]

33 hz I think it was.

Change port length to 13" and adjust the dimensions a little to give you the same 1.25ft^3 air space.

 

[jeremyblevins 10+ year member]

well i have 1.24235 cu. ft. per side is that close enough?

 

[jeremyblevins 10+ year member]

and 13 wont fit because my box is only 13.5 deep. bass box pro is giving me 33.25 at 3'' with 9.708'' depth

 

[RAM_Designs 5,000+ posts]

Are you using the gross volume or the 1.24ft^3 volume to figure port length?

 

[jeremyblevins 10+ year member]

i'm confused now it's giving me 33.78 hz at 11''.

 

[jeremyblevins 10+ year member]

didn't know it mattered? i thought the frequency was determined by the port area and length not vb?

 

[RAM_Designs 5,000+ posts]

didn't know it mattered? i thought the frequency was determined by the port area and length not vb?

Nope, box volume is very important, which is why if you change it you get a different needed length in order for the same tuning(assuming same size port. The easy way to look at it is that three things affect the needed port length.

1) Box volume

2) Port area(and shape, to an extent)

3) Tuning frequency

 

[jeremyblevins 10+ year member]

okay maybe i should start from square one on here again haha.

so here's the deal i'm wanting to build a box to go in the trunk of my mustang the type r's are going to be powered by an audiopipe 15001d so around 500ish watts rms each. so these are the dimentions i have to work with.

Front width 44''

Back width 31''

depth 13.5''

Hight 13.5'' for 6'' of depth then starts an angle down to 6'' of height of the very back.

and i'll be using 3/4 mdf

the box i designed to pretty much take up all that arear is around 2.4478 with a divider between the two speakers for protection

 

[jeremyblevins 10+ year member]

so i figured out i was reading alpine's manual wrong the optimum internal volume after displacements is 1 cu. ft. . Does this sound right of should i do bigger? and if so how much can you deviate?

 

[jeremyblevins 10+ year member]

okay so i redid my calculations and i have 1.204 cu. ft. per side before port displacements. and if i assume .046 volume for the port then my Vb will be 1.158 cu. ft.

with a 3" port at 11.25" bass box pro is giving me a number of 34.65 Hz does this sound right? and would these numbers work for this sub or should i just go for a slot port?