[adambeazley]

Ok that title might be a little missleading because the real question is about the volume of the back of the sub. Basically alpine says the SWR-1042 needs a sealed box with a volume of .6 to .8 Cu Ft. Now is this volume including or excluding the rear side of the sub (ie. the magnet and bracing of the sub that will be enclosed in the box). In other words, if I make a box that is .80 cu ft and then put the sub into the box I actually wouldnt have .80 cu ft of usable volume, instead i would have like .75 (I dont know exactly how much volume the back side takes up yet).
So my question is:
is the volume recomendation by Alpine include the volume of the back of their speaker?
thanks

 

[onefunkyfreshdj]

It includes the area taken up by the subwoofer. Here's a good calculator to use..... just remember when measuring... use the INSIDE dimensions... not the outside. You don't need to worry about how much space a subwoofer will take up, all they want is the area that the subwoofer will go into (interior dimensions).

Box Calculator

Sub Wiring Wizard

 

[eddiemoney]

Also take note, that if you lean towards .8 the sub will probably be a little louder

 

[adambeazley]

Thanks for the quick responce. That is good to know, this way I can save more space in the trunk. Unfortunately I have a very organicly shaped box so that box volume link wont work for me. But I found a way to get the volume which I will share in case anyone else is doing a strange shapped box. Basically I just made a full scale mockup from that expanding foam that plumbers use. Then stick it in a plastic bag and fill the bathtub up with water and mark the water level with a crayon. Then get a bucket and pour a gallon at a time into the tub marking as you go. Then drain the tub down to the first mark and submerge your mockup and look at how may lines the water goes up and this will give you a prety good estimate of your volume. 5.65 gallons equals .75 Cu Ft.
Then fiberglass over the foam and cure. Then you can dig out he foam and swish around some gasoline inside to clean the rest off. And there you have a custom fiberglass box with the correct inner volume.
thanks guys
peace

 

[eddiemoney]

Or you could just use packing peanuts.....

 

[Soundguy50]

i always liked rulers and wood.....but hey i guess im old school

 

[eddiemoney]

Yah, thats typically what i do too, but he says his is odd shaped, packing peanuts is the easiest i have found for that.

 

[adambeazley]

well with the packing peanuts you have to build the enclosure first then hope its right. My method I can continue to shave and sand at the foam mockup until its just right. Then wrap it with carbon fiber and fiber glass. I really wanted to make a carbon fiber box because it has great acustical properties, better than any wood or fiber glass IMO. I used to work for a guitar company and we manufactured Carbon Fiber guitars and they really sounded better than any wood guitar put up against them. Louder and more responsive. The box Im making is in the same location as Alpmans custom box and very similar. I really did have that Idea in my head before I saw his box, but I was going to use carpet to finish it off instead of the ABS that Alpman used. But after seeing how nice the ABS looks I think Ill give that a try.
peace

 

[eddiemoney]

The only place I could get cheap carbon fiber was from leftover stock from Boeing, the stuck is kinda hard to work with I always though. I will look forward to seeing some pics if you can get some.