# How do you calculate approximate volume of irregular objects?

Discussion in 'Archived Threads 2001-2004' started by Mike Dr, Jan 28, 2002.

1. ### Mike Dr Stunt Coordinator

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I want to put the plate amp inside my upcoming sonosub, and I have no idea how to figure out the volume of all the extra boards, the amp, etc that are going to be in there. I want to approximately figure out the volume so i can get somewhat correct measurements in LSPCad. Also, putting the amp and bracing inside will restrict SOME airflow.. is there a rule of thumb for minimum opening to let enough air volume through to not affect sound quality/response of the sub?

thanks

2. ### Greg Monfort Supporting Actor

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Break it down into separate boxes, calculate the approximate volume of each, then add up all them cubic inches and divide by 1728 = ft^3.

GM

3. ### Mike Dr Stunt Coordinator

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heh yeah .. nothing like taking curved objects and breaking them into boxes suddently memories of calculus are coming back

4. ### Todd Beachler Stunt Coordinator

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fill it with water and then measure the amount of water used! Well, that's what you'd do in any other situation, but I doubt you'll want to use this method on your home theater equipment.

5. ### Neil Joseph Lead Actor

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Douuugh!!! That was my suggestion.

6. ### Wayne Cook Extra

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The water displacement method can work, and it is very accurate.

Simply wrap everything with a large sheet of thin plastic wrap, use a vacuum to do a "imitation shrink wrap" and you are all set. This has worked for me with an impromptu underwater camera shot.

7. ### Jason Poirrier Extra

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Similar to the water displacement idea, but less messy, you could use Styrofoam packing 'peanuts' to fill the enclosure. Now you just need to calculate the volume of the packing material - which should be pretty simple. The easiest way would probably be to get a large box and fill it with the peanuts. From here it's just WIDTHxDEPTHxHEIGHT (that the peanuts fill the box to.) Although slighty less acurate than the water dipslacement, it should be pretty close.

8. ### Mike Dr Stunt Coordinator

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ok guys.. how about something useful

9. ### Neil Joseph Lead Actor

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Buy yourself some gravel (or sand) and pack it in your enclosure. Then measure the volume of the sand by putting it in a square/rectangular box. Do you have the ports mounted already. You need to account for port volume. Also, protect the driver from the sand.

10. ### Neil Joseph Lead Actor

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What exactly is the "irregular" shaped enclosure that you are using?

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