15 replies to this topic

[carts60]

I need some help working out the specifications for a ported enclosure for my sub.

I'v never been a whiz at maths so a bit of help wouldnt go a miss if you may.

The sub is a JL 6w3v4 and needs a ported box with a volume of 0.25 cubic feet.

I'v worked out the dimensions of the box (i think) which would provide the correct volume.

All measurements are in external values in inches
Width: 8
Height: 13
Depth: 6.1

Here are all other figures you may need:
Resonance: 41.8 Hz
Qes: 0.533
Qms: 11.027
Qts: 0.508
Excursion: 0.35"
Driver Displacement: 0.03 cu. ft

The box needs to be tuned to 38hz.

Ruckus, im looking to you for this one!

Thanks a lot guys

[Ruckus]

give me 30 mins...

[Ruckus]

are you sure this is a 6w3 V4

JL site only lists a V3 ??

http://mobile.jlaudi...s.php?page_id=2

[Ruckus]

ok I need more info to check your measurements .

What sort of port does this use? slot or round.
Whats the ports measurements?
What thickness of materials will be used.

[chilesy]

Dims you gave work out just over 0.2 cuft if using 18mm mdf . If the box was 8" wide 13" high 8.5" deep it would aloe for port displacement if using a round port , if you want slot ported it would need to be a little larger as it takes up more volume

[chilesy]

To tune to 38hz you would need a round port 2" wide and 20.2" long , this won't all fit in the box but would be simple to have some external . Tuneing small boxes does need alot of port length which is can be a problem but 2" pipe is easy enough to cut and join

[Ruckus]

To tune to 38hz you would need a round port 2" wide and 20.2" long , this won't all fit in the box but would be simple to have some external . Tuneing small boxes does need alot of port length which is can be a problem but 2" pipe is easy enough to cut and join

Changing the port diameter can shorten the port length though. But it will get so small you will get nasty port noise.

For this driver i would stick to a slot port.

[chilesy]

Yes you can't go lower than 2" or will chuff like mad , with a slot port the box will have to be larger as the port will take up more box volume due to the port wall thickness but will work well

[Ruckus]

Yes you can't go lower than 2" or will chuff like mad , with a slot port the box will have to be larger as the port will take up more box volume due to the port wall thickness but will work well

JL have specs on there site for a slot port box for this driver tunen it to 38hz funny enough.

It not hugely bigger that the size carts posted...!?

[carts60]

OK!!!!

So firstly: slot port not round

All further info or details i havent given can be found Here and HERE

I was hoping to make the driver and port both be on the same face/side as id like them both facing forward rather than the sub on one side.

My dimensions i'v posted have been slightly altered so the front face is large enough to fit the driver and other dimensions have been slightly fiddled from specs to stick to the recommended volume give or take.

Basically can someone please knock up the correct dimensions for the port and sub both on the same side?

Ist going to be where a centre console usually is, so thinnest side facing forward.

Thanks again guys

[Ruckus]

OK!!!!

So firstly: slot port not round

All further info or details i havent given can be found Here and HERE

I was hoping to make the driver and port both be on the same face/side as id like them both facing forward rather than the sub on one side.

My dimensions i'v posted have been slightly altered so the front face is large enough to fit the driver and other dimensions have been slightly fiddled from specs to stick to the recommended volume give or take.

Basically can someone please knock up the correct dimensions for the port and sub both on the same side?

Ist going to be where a centre console usually is, so thinnest side facing forward.

Thanks again guys

I have not designed slot ported boxes before and my software is basic and cant do them

But if you have used the same volume as the JL design and the slot port has the same Width/Height/Length and as long as you have a decent gap at the ports start point inside the box (2" or more) then you should be ok.

Edited by Ruckus, 27 July 2011 - 07:59 AM.

[carts60]

i'll get some MDF tomorrow and see how it goes in that case.

[chilesy]

Put up the actual max dims you have mate as just adding a bit here and changing things slightly will throw the running off , built and designed over 20 slot ported boxes so can help out bud if you need it

[Ruckus]

Put up the actual max dims you have mate as just adding a bit here and changing things slightly will throw the running off , built and designed over 20 slot ported boxes so can help out bud if you need it

What software do you use chilesy ?

[chilesy]

Put up the actual max dims you have mate as just adding a bit here and changing things slightly will throw the running off , built and designed over 20 slot ported boxes so can help out bud if you need it