How to calculate cubic air space for sub-enclosures???
#1
Reppin Stage 7
Thread Starter
iTrader: (5)
Join Date: Nov 2002
Location: San Benito,Texas
Age: 42
Posts: 4,767
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 308 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...
#2
Registered!!
iTrader: (20)
Join Date: Sep 2002
Location: Cleveland, OH
Age: 42
Posts: 4,111
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 305 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.
#3
Registered!!
Join Date: Aug 2001
Location: New York, US
Age: 46
Posts: 960
Likes: 0
Received 0 Likes
on
0 Posts
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.
#4
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.
#5
i boogie for the raindrops
Join Date: Oct 2001
Location: Jackson, Mississippi
Age: 40
Posts: 4,497
Likes: 0
Received 1 Like
on
1 Post
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.
#7
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.
#10
i boogie for the raindrops
Join Date: Oct 2001
Location: Jackson, Mississippi
Age: 40
Posts: 4,497
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 0
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.
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
alxz310
Mechanical Problems/Vehicle Issues and Fix-it Forum
10
07-30-2015 12:18 PM
7thgensurvivor
Archive - Wanted Parts (WTB's)
2
07-05-2015 12:17 PM