How to calculate cubic air space for sub-enclosures???
06-17-2004
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How to calculate cubic air space for sub-enclosures??? Just as the title reads.. I wanna figure out how to calculate air space to make sub boxed to spec according to the manufacturers specifications... Just wondering if anyone has had any experience doing this...
06-17-2004
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Rep Power: 304 1 cubic foot = 1728 cubic inches
multiply length, width, and heigth together to get your air space. NOTE: you will need to use the internal dimensions, not what you measure on the outside. so if you use 3/4 MDF, subtract 1.5 inchs from each dimension.
multiply length, width, and heigth together to get your air space. NOTE: you will need to use the internal dimensions, not what you measure on the outside. so if you use 3/4 MDF, subtract 1.5 inchs from each dimension.
06-17-2004
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Rep Power: 0 Thats right. You want inside dimensions, not the outside dimensions. For example, take a perfect 1 cu ft box, 12"x12"x12' made with 3/4" MDF.
Outside (12"x12"x12") / 1728 = 1 cu ft perfect.
Inside ((12" - 3/4" - 3/4") x (12" - 3/4" - 3/4") x (12" - 3/4" - 3/4")) /1728 = 0.67 cu ft.
So even though the outside of the box take up 1 cu ft of space in the car, the woofer is really only seeing 0.67 cu ft of airspace inside the box. Huge difference.
Outside (12"x12"x12") / 1728 = 1 cu ft perfect.
Inside ((12" - 3/4" - 3/4") x (12" - 3/4" - 3/4") x (12" - 3/4" - 3/4")) /1728 = 0.67 cu ft.
So even though the outside of the box take up 1 cu ft of space in the car, the woofer is really only seeing 0.67 cu ft of airspace inside the box. Huge difference.
06-17-2004
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Rep Power: 275 if you're doing it by the manufacturer's reccommendation, like what everyone already said, it's for the space inside the box which does not include the volume of the MDF.
note that some manufacturers will give you a number which already takes into account the speaker's displacement while others might not.
if you use the sub's specs to calculate a custom size box, you'll have to take into account the displacement of the speaker.
note that some manufacturers will give you a number which already takes into account the speaker's displacement while others might not.
if you use the sub's specs to calculate a custom size box, you'll have to take into account the displacement of the speaker.
06-18-2004
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Rep Power: 0 youll never really have to worry about taking displcement into account. highest displacement ive ever seen is .21 or so cubic feet on one of the super subs. displacement is usually .12-.17 on average sized subs, and if you say you can notice a difference in .12 cubic feet, then youre full of ****. and if you are uber **** and forget to calculate displacement, then just invert the sub.
06-18-2004
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Originally Posted by LudlamTheory
youll never really have to worry about taking displcement into account. highest displacement ive ever seen is .21 or so cubic feet on one of the super subs. displacement is usually .12-.17 on average sized subs, and if you say you can notice a difference in .12 cubic feet, then youre full of ****. and if you are uber **** and forget to calculate displacement, then just invert the sub.
you're right but you might as well do it if the numbers are given...it's just good practice. it may be a tiny discrepancy but discrepancies can add up if you're rounding off on every little step. i try to maintain a good balance of perfection and efficiency. it's not hard subtract displacement.
06-18-2004
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Originally Posted by mohawkboom
And if your a columbian with 5000+ songs on CD's than you know your ****.
12,000 you damn canuck mohawk mutt
06-18-2004
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Originally Posted by turboslug
you're right but you might as well do it if the numbers are given...it's just good practice. it may be a tiny discrepancy but discrepancies can add up if you're rounding off on every little step. i try to maintain a good balance of perfection and efficiency. it's not hard subtract displacement.
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