I am considering making my own subwoofer enclosure and understand a little about its construction.

I already understand that you need a minimum amount of airspace to accomodate a sealed box, but what about if you exceed that - does it improve or degrade the output? Where can I find the airspace needed for a sub (I have two old JL 10w5 subs from my last car).

I am thinking of trying to construct the fiberglass enclosure with a MDF top. Exact calculation of airspace is going to be difficult - hence the reason for asking... Planning on both of the above subs to be used.


TKMak
______________________
'01 silverstone/black

 

Having a box that is not the proper size will have a dramatic effect on the sound quality and quantity.

Here is the link to a .pdf file with the stats on the sub and recommended box specs. http://www.jlaudio.com/subwoofers/pdfs/10W5_BDS.pdf

Also note that the spec sheet DOES NOT recommend a sealed box.

Hope this helps.

 

If you feel like going nuts, there's a couple programs out there that can help you plan your box. One is Blaupunkt's "Blaubox". Another I ran across recently is from a Swedish speaker manufacturer called DLS - check out DLS Box 2000.

Though these programs can only provide mathematical approximations of your frequency response, they're still useful planning tools.

Enjoy!

-Jason

(awaiting my DLS X12)

 

voodoo_s2k,

just after i posted, I saw the same link you posted... Being that fiberglass seems the route to go, does the port length change for the dimensions of the box? how does one calcuate volume for such for an amorphous space when using fiberglass?

tkmak
__________________
'01 silverstone/black

 

I imagine you could go slightly oversize by design and figure the true volume by filling with water and measuring the liquid. Then add material inside to fine-tune the true volume.

 

Pen,

One would actually want to UNDERsize the box slightly, and add fluff to increase the perceived size of the box.

I've never used fiberglass for a box before, so can someone explain why calculating volume is so difficult? Unless the box is made up of compound curves, can't you just break the dimensions up into triangles and rectangles?

 

calculation would be difficult... the water would probably work.

fiberglass boxes, at least by my research, is constructed by lining the area to be used with aluminum foil or some time of relief, then laying the fiberglass strips with resin until it hardens. It is then removed from the trunk. The process ensures an intimate fit with the curvature of the tool recess. Hence the difficulty in area measurement. I was hoping somebody had an easier way to measure the area other than using water.

Fiberglass seems the way to go... Although with the difficulty, I am thinking of just going the mdf ported box method - despite the weight...

TKMak

___________________
'01 silverstone/black

 

It wouldn't be as accurate, but you could always line it with plastic and use sand to measure the volume...