Sticky Packing peanut volume measurement

I was just thinking about that the other day.  Proper use of peanuts to measure volume space.  I would also like information on it.

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I have not failed. I've just found 10,000 ways that won't work.

When you do not know what you are doing and what you are doing is the best -- that is inspiration.

It really isn't that difficult. If you fill a container that is 1" x 1" x 1" with packing peanuts, you get 1 ft3 of volume. Moving this amount of packing peanuts into another container that is of a different shape, but the peanuts still fit will yeild the same cubic volume.

Othewise, if you have an oddly shaped enclosure (fiberglass, let's say), fill it with peanuts the same way. Then you need to take those peanuts out and put it into a cardboard box that has easy dimensions to measure, and find the volume the peanuts consume in that box. That is the interior volume of your 'glass enclosure.

DXAV

Hahaha, yeah, good call, Boxmaker. Thanks!
I usually don't denote measurements in that style -- now you know why!

DXAV

lol had to say something b/c i could see some newbie wondering why he is only able to measure one peanut in his 1" x 1" x 1" measuring box at a time.  and wondering why his box sounds so crappy.  You never know about people today

I can easily get 4 peanuts into a 1" x 1" 1". Can't you?!

Seriously, though. Did my explaination work for you s7726 and Melted Fabric?

I noticed it is a stick now, so it probably should be ok.

DXAV

ok  say you have measured in a cardboard box . How do you put that measurement into the (fiberglass enclosure ) before you do the frame work and put the resin on the jersey material or fleece? do you just guesstamate? I would hate to build a box and then go cut the holes for the speakers and fill it with my peanuts and have alot left over..or is there  a way to compensate for the lost peanuts? I know I probably sound stupid and the answers probably in front of me,but , oh wells.

I have heard the general concensus is to guess BIG, then you can put in some extra random space taking material if it's too much space.

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Gavin
SWEDISH RICE!

Well, after the material is stretched over the ring and back, I just don't seal one small hole, and fill the peanuts thru that. Then I take them out, put them in the box, and measure. Then if the ft3 is good, I seal the fiberglass enclosure up completely. I usually use hot glue, holds well, and is not permanent. If you are stretching over MDF, then use a staple gun for the final streching.

DXAV

boxmaker85 wrote:

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lol had to say something b/c i could see some newbie wondering why he is only able to measure one peanut in his 1" x 1" x 1" measuring box at a time.  and wondering why his box sounds so crappy.  You never know about people today

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i had a bad picture of that in my head too, but it was me doing the work -_-
thanks for clarifation lol

ok im so friggin confused. Im building a custom encloser that molds to my trunk. Im not really sure what you guys are talking about with those packing peanuts. I know you need the right volume for your subs to sound good. Im just not sure how to achive the right volume. i guess this is where those plastic peanuts come in right??? so what do i do or how do i measure it?

the "packing peanut" method can only tell you how much volume is in an enclosure the best thing to do is try and measure the space of the enclosure as it is being builg by getting an average width, heigth and depth and figuire airspace from that but remember build it slightly larger becuase it is easier to subtract airspace then add more once your done add packing peanuts to get an closer measurement of airspace then fine tune from there.

Thanks for the clarification Shane. (I was about to ask, why kinda peanuts are you supposed to use and how tightly do you fit them.) Thanks to Stanford as well (I prolly shoulda figured that out but my brain is on leave right now.)

Though I read somewhere, if you build slightly smaller, you can always stuff it with acoustistuff or whatever, right?

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1998 Monte Carlo w/
Eclipse CD8454
2xRockford 5.25" Power 2-way T152C
2xRockford 6"x9" Punch 3-way FRC4369
1xMemphis 16-MCH1300 5-channel
2xKicker 12" L5 Solobaric-2 Ohm

i actually dont care for using packing peanuts... i put a garbage bag into the enclosure and poor water in till its full then dump it into a bucket and measure liters than convert to cubic feet

... Water leaks from trash bags, easily.... I guess if you don't have any water issues that'd work. I personally am not a friend of water.

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1998 Monte Carlo w/
Eclipse CD8454
2xRockford 5.25" Power 2-way T152C
2xRockford 6"x9" Punch 3-way FRC4369
1xMemphis 16-MCH1300 5-channel
2xKicker 12" L5 Solobaric-2 Ohm

thats why you get the heavy duty contractor bag... ive neve had one leak on me yet

I have... Like everytime. I really figured that ya know, nails don't get through it easily, why would liquid. Yeah, the porch was pretty wet after that idea. Atleast I got it outside before it leaked. GIven for short use, that may not be a problem, but prolonged could be bad. And anyways, water is constantly wanting to move, how do you keep the bag from just tipping over and pooring all out? Sure you can do it again, but you know how pissed and demotivating that'd be? What is the economical ratio on the two ideas? (Mainly how much are the bags vs the peanuts which are like infinite for reuseable.)

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1998 Monte Carlo w/
Eclipse CD8454
2xRockford 5.25" Power 2-way T152C
2xRockford 6"x9" Punch 3-way FRC4369
1xMemphis 16-MCH1300 5-channel
2xKicker 12" L5 Solobaric-2 Ohm

I like the bag idea. But why not sand in the bag? Alot of boxes have MDF and water could destroy your whole project with a leak or spill. Sand would measure very accuratly and with the bag it would fix the clean up problems associated with sand.

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Nik
Jeeputer Progress
[|||||||||||-] 90%
Check it out.

What happened to plain peanuts? Unless you guys are doing a perfect competition enclosure .001 cu.ft. won't make a difference for you guys i promise. You will be more worried about the air pressure more than if your box is off by ten thousandth of a cu. foot. IMO.

umm exactly when are you guys doing this "peanut packing" is this before you soak the fleece or after?

This is a reply to the original subject about volume.

Lets say someone has a strange shapped box (like me).
First you can make a full scale foam mockup of the box (using either expanding foam or whatever). Then get your mockup and a 1 gallon bucket(milk jug) and go into your bathroom. Fill the water up to a level where you can submerge the entire mockup, then mark the side of the tub with a sharpie, add a gallon, mark with sharpie, add a gallon, mark with sharpie, etc.... unti you have marked enough to match the desired volume. (Ex: 5.5 gallons = .75 cubic ft). Now submerge the mockup and see where you stand with your volume. Is it too big, then sand it down, too small them add some foam until you get it perfect.
Now wrap that beyotch in foil and start laying up your fiber glass. This way you can get an acurate volume before you start building the box, instead of measuring it after and hoping you got the right CU FT.
I hope this helps,
Peace

dont forget to subtract your material thickness bracing ext. it adds up quick

Alright I know I am about 3 months late with this but maybe the next guy will get it, You have to do all of the things but screw the bag trick, Take the area your going to use for your enclosure, inside your car/truck/bus whatever. Measure that area IN THE VEHICLE. you'll get an outside measurement larger than you could make the enclosure. Build what you can out of wood acounting for any variences, such as displacment, bracing, seat belts? mach up fitment , make rings/squares, double check volume is larger than needed, paint ALL the wood with 2 coats of resin being sure to seal any corners with caulking 1st and allowing to dry. Then streatch in cloth fleese/grill cloth. Take a quick measurment of the contraption trying to get the best idea of what you've got going on. Now if satisfied that your enclosure if definatly LARGER than needed by about 1/2 cube or so maybe better. Go ahead and be sure it still fits where you want it to go. Now, resin up the cloth a few times NO MORE THAN 3 resin is weak when applied without matting. Now you have an air tight/water proof enclosure. The peanuts wont tell you about air leaks, and if you crumble up a bunch of peanuts you'll fit alot more in the same area as the new ones,   (I am a firm disbeliver in the peanuts deal) now get your self a shapie, a few empty gallon containers a helper and about 30 min free time. Start filling that baby up with water marking down each gallon as you go, (If you design has holes every where cover them up, seal them or dont cut out the holes till after the volume is calculated.)
Okay your done and you have 17 and a little fro the last one gallons in their, drill a few holes to let the water out ( i'd take this one out side) Do the math if your good go for fiberglass, if your over get some expandable foam, (its light weight) spray in what you need and coat it with resin after it drys. Repeat the water steps if your trying for perfect volume, or at least one more time if this is ported, slot ported, band pass, as those are a bit more particular on the volume, for reasons such as tuning and shiot, well im done with the book, have fun and get a good gallon of acetone or moms finger nail polish remover you'll need it!