Well, make sure you use water to measure the volume when you are done. For .9 cubes it will need to fit: 6.7324675 gallons [US, liquid]

It sure looks like it would be easy to get .9 cubes out of that area but most times people are getting around .7 from that area or they aren't measuring the box right and saying it's bigger from what I've seen on the net.

 

I also have one of BJ's 12" drivers-side stealthboxes.
I have a JL 12W6 in it powered by only 250 watts (JL 250/1 amp) and it hits pretty hard.

 

I plan on filling it and measuring the one I'm building. The one I'm selling I'm guessing at it's volume. All I can tell right now is the one I'm making it real close to 1x1x1 foot on the exterior and I'm taking advantage of all the space up to the LR speaker. Gonna be a little difficult to measure the volume to 7 significant figures, but thanks for saving me the time of looking up the conversion. I'll attach some pictures once I get it built and if anyone is interested on how I did it.

I was actually thinking it would be easier to weigh it empty then with water in it to get the volume. I'm not sure my bathroom scale will give me to much accuracy though... lol

Anyway if someone is interested in the 12" box I'm selling send me a line cause I'll prob just put it on e-bay starting at $150 this weekend.

Brian (zigcaddy@aol.com)

 

I'm just saying don't get bummed out if after you do it you aren't at the .9 cubes. If the box is 3/8" of an inch think that's around .2 cubes that will be taken up just by the fiberglass alone.

You'd have to get .2 cubes or so out of the LR speaker area for the other area is around .7 or so cubes if you still want to easily be able to remove it from the car from what I can see back there.

When building one my brother and I did I thought it looked pretty good until we later found out it was only .7 cubes. Surprised me for I thought it would have been bigger. The external volume would be around .9 though, oh how I wish external volume counted with speaker enclosures sometimes! :-)

 

forget about water, use packing peanuts.

 

Packing peanuts aren't accurate enough. I've had too many people misquote the size of boxes and to use a material that can expand and contract and also has room for air in-between it just isn't accurate enough or so it seems.

You can't cheat water, as long as it's measured correctly it's one of the best bets for an accurate measurement of box volume of fiberglass enclosures.

 

why would it matter if it is off a little. is it going to make a difference of .03 in QTC, how about .05.... basicly playing a numbers game because a box might be off by 5% isn't going to make a difference. Trust me here, there is going to be no difference if a box is .85 or .9, there is going to be no difference between .9 and .95, simple rule of thumb with fiberglass.... once you are to the point that you measure the volume it is generally too late to change a lot....

 

Umm... no I'm not changing anything at this point. I just measured the volume of it using water and weighed it. It wasn't filled to the very top as I have a couple more layers of fiberglass to lay so I tried to account for that by not filling it quite to the top. But it came out to be .81 cu ft. For IDV2 12" speaker .85 cu ft is ideal. So I'm hoping that filling it with polyfil and that enclosure size it should have the SQ that I'm looking for. When I get it done I'll post some pics as it is the first time I've tried this and I think it is turning out pretty good.

Brian

 

I wasn't talking about the end result of how it effects the speaker performance but just that of box volume.

You saw it right here in this thread. He said he got .81 out of the box. How are some people saying they are getting a full cube out of it that area or .9 cubes of internal volume? Are they building the box differently or are they just not measuring it right. Could be one or the other.

Now onto speaker performance in the box. If they are only getting .7 cubes of internal volume out of their box lets say and they say it's a 1 cube box, well that's a 30% decrease in box size which is pretty big. I have seen some boxes that say they are 1 cube for that area (in Camaro's) but after looking at them they just don't add up to looking like they are one cube.

Mostly talking from the standpoint of the people that sell them and say they are such and such size. For the people building them on their own, you are right, once the box is built that's the size it's going to be.