Measuring Cabinet Volume with Liquid?

[Zero Cool]

I have a pair of small plastic automotive enclosures that i need to determine the internal volume of. The box shape is a complicated shape so i can only estimate the size. I need a more accurate method of determining the internal volume.

Can i use Liquid and a graduated cylinder to measure accurate internal volume? Could i simply fill the cabinet with water and then pour the water into a graduated cylinder to determine how many liters?

There is a small tuned port molded into the case. should i tape off the port on the inside and not include its internal volume in the overall volume calculation? I would imagine that would be how it should be done. I can then measure the port volume seperatly.

Thanks


Zc

[ocaukrell]

Yup, close enough to the money.
As you say just tape of outside end of port (where it exits the box), fill with water, then pour that into a measuring jug.
Volume of port shouldnt have any real effect on volume.

[tade]

I beg to differ about the port. If it is easy to get to the inside of the port to put on some tape then do that. The port ats differently than the rest of the box. And, with a small enclosure its volume may be more important to take into concern.
Otherwise that methos is a sound one

[Zero Cool]

Sweet, ok then my reasoning is sound. I can get to the port very easily. i can tape it off inside the box. so that way i will only be measuring the true inside volume of the box. the port would essentially be outside the box.

With the port taped off inside. i can fill the port with water and measure just the port volume.

Thanks. I am off to my local suplus store in the morning to buy some graduated cylinders i saw.


Zc

[xplod1236]

If you have a scale, you can weigh the water. Weight should be 1 gram/mL. This way, you wouldn't need a graduated cylinder.

[joe carrow]

You could also seal it, change the inside volume by a known amount, then measure the internal pressure to figure out the volume.

[ruerose]

use sand if water is inconvenient.

[pinkmouse]

Seconded. Sand, or even rice, would be much neater.

[Zero Cool]

Thanks everyone. Water would work well as the cabs are plastic so its not a big deal to fill them up. plus if any spills, its easy to clean up



Next step will be to find a suitable replacement woofer for these cabs. its a very odd size and shape. the round part of the driver measures 114mm (4-1/2") but the undersized square frame is 106mm.




These are made by Nokia for BMW. The frames are made of plastic. they look pretty heavy duty, and in reality for 4" driver there not bad. but there not good either.

I have searched madisound, and Parts Express, even MCM and the only thing i can find that is a drop in a a couple of Fostex full range drivers. but they look more like a midrange driver then a woofer.

I am most likley going to have to fab some adper rings, or do some plastic carving to get a driver to fit in these. Once i know the cabinet specs, i can then try and find a more suitable driver.



Here is a shot down the inside of the cab. notice the two ports in the photo. only one is active. the other port is sealed of inside. so i can open it with a dremel tool if need be. Currently these sound like they look. very bad hahahaha

I will be setting up the SMAART system and do some freq resp. tests on these boxes and see just how bad or good they are.

[ocool_15]

So is this a "stock sub" or is it a woofer in a cabinet like a 2 way component?