Well the other week i decided i need a bit more boot space so me and my father cut the box down a little bit to make it fit in better.

Well we didnt takew that much off so i thougt it wont make ne difference to how the sub performs, well i was wrong. my sub now sound **** and isnt how it used to be.

My question is, could i make a new box that is wider and not as deep as it used to be so that its still the right volume inside, and if im able to do that, how do i know how big to make it so its the right volume?

Hope that makes sence.

Well the other week i decided i need a bit more boot space so me and my father cut the box down a little bit to make it fit in better.

Well we didnt takew that much off so i thougt it wont make ne difference to how the sub performs, well i was wrong. my sub now sound **** and isnt how it used to be.

My question is, could i make a new box that is wider and not as deep as it used to be so that its still the right volume inside, and if im able to do that, how do i know how big to make it so its the right volume?

Hope that makes sence.


Hi!
Is your box sealed or ported?
If its a sealed box try filling it half full with dacron...this slows down the air inside the box and tricks your sub into thinking its in a larger enclosure. If you havent taken masive amounts out of the boxs volume it may help somewhat (sealed enclosures are more tolerant to volume variations anyway).

In response to your question - yes as long as the box volume is the same its shape is more or less irrelevant (for a sub) so you could definitely make it wider and less deep...

... do you know what the ideal volume is for your sub?

Good luck

Yeah we put that dacron in and it made it a bit better but still not how it was be the changes.
Its a sealed box aswell.

I know the ideal volume that the box should be (70.81)

Just need to know how i make a new bow so that its the right volume.

Yeah we put that dacron in and it made it a bit better but still not how it was be the changes.
Its a sealed box aswell.

I know the ideal volume that the box should be (70.81)

Just need to know how i make a new bow so that its the right volume.


You need a 70 litre box? R u sure? are u running an old skool paper coned pa driver 15 incher or something???

Seriously what sub r u runiing coz 70litres is HUGe for a single woofer....

its a 15" JL

http://img357.imageshack.us/img357/6852/sub5xm.jpg

Ahhhh now all is explained!

Hmmm - just wondering what kinda amp your running into it?
Probably not what you want to hear but a good 12 with lots of clean power will work in a box at around 35 litres and sound soooo much tighter anyway...


whats the maximum width and height you can go to? this will tell you your depth to get 70 odd litres...

well its in a 3rd gen and the height is pretty much what the height of the box was at first 406 mm, not sure on what the width is.

And i wanna keep the 15 cus i loved the sound of it when it was working properly.

volume of a box is:
Length x width x depth

So pick the 2 variables you want and use them and the known volume (70.81) to find the remaining variable.

i.e.
You know you want you box to be 700mm long and 500 deep.

So the height would be:

70.81ltrs / (0.7m x 0.5m) = 3.5m^3
3.5m^3 x 1000(to get to mm) = 350mm

This is INTERIOR dimensions, so does not include the thickness of the wood.
Hope that helps!!
Pete

Ahhh i just dicovered something interesting
Your box dimensions are calculated allowing for both materal thickness and woofer displacement - VERY CLEVER! (thats why my volume calculations didnt add up!!!)

OK as a rough guide - assuming the same material thickness (should be 19 mm mdf) and allowing for the same woofer displacement (well its the same woofer)

Try something like...

745mm * 405mm* 315mm the GROSS volume is NEARLY identical (should be close enough for a sealed box) and it saves you104mm depth?

Near enough to what you want?

:confused:
I just used WinISD to calculate a box size and it came up with 149.9 ltrs for a sealed box!!!
:nuts:

I checked what specs it had on the sub as it was already in the list they provide and its only got a couple specs which might be the reason...

Yeah

JLs website had there recommendations which iis where his 70.8litres came from

but that was because ther calcs already allowed for woofer diplacement and timber thickness... there ideal box has a gross volume of over 95 litres!!! GODDMAN HUGE (why i hate 15s!) but still more user friendly than 145! (bet that would move your heart in your chest tho!)