my 15inch sub's enclosure issue!

[rider60]

well got a GT4-15 JBL 1000W, 250W rms sub recently!

i installed it on a plank in my viva on the rear parcel tray, for which the whole boot acts as an enclosure, but, it seriously lacked the punched that i am used to now!, so was planning for an enclosure!

i have calculated the dimensions as recommended by the JBL technical data sheet provided!

and i decided to go in for the vented/ported box volume type, which recommends a 6inch port and 113.27lit of space in the box!, however i thought of getting one made from a local carpenter with the dimensions i want him to make, so here is how i intended to order it

i thought of a plane rectangle with 16*24*16.125"=6192cubic inches=4cubic feet=113.27lit as recommended!

now my query is is the shape fine or should i resort to a more irregular shape like the JBL's sealed enclosures?
will the shape have any bad effect on the sounding of this sub?

i am powering this using a 2channel 160W RMS output sony 602 amp!, and pio6850 HU!

all suggestions are welcome!, the end result i wanted is good punchy and tight bass!

[navin]

Originally Posted by rider60

now my query is is the shape fine or should i resort to a more irregular shape

i am powering this using a 2channel 160W RMS output sony 602 amp!, and pio6850 HU!!

1. irregualr shapes are better because the reduce standing waves inside the box.

2. get a bigger amp the 602 is barely passable. I would suggest 250-300W rms.

[s0uljah]

Yash,

For the tight and punchy bass your really going to love the results from a well built sealed box but this also means the sub would need more juice than the 602 as Navinji has mentioned.

Choose the box builder carefully man because any old carpenter might not do the best job. The enclosure will dictate the sound at the end of the day.

[rider60]

well basically, i want the dimensions for the box so that i can have it built with the authentic MDF material that i can source here, a friend of mine has a shop, the box will be made under my supervision so i will see to it that its well made with the fiber glass coating finish! thats the main idea behind asking for the shape and the dimensions for the box!

and i will get a good 250-300RMS mono amp later on, but initially i want the box dimensions and shape!

EDIT:as i have already written the dimensions i have mentioned are of a rectangle!

[low_bass_makker]

That box is quite big will eat up the whole boot. You can try a bit smaller one it will increase the punch but will decrease the low end. So no need to worry 70-80 liters will also do.

[Xmax]

I second LBM. I think you can do away with a smaller one. Also ensure that the parcel tray MDF plank cut out is reduced in size since you told that your 15" were rested on them earlier.

[navin]

Originally Posted by rider60

the box will be made under my supervision so i will see to it that its well made with the fiber glass coating finish!
EDIT:as i have already written the dimensions i have mentioned are of a rectangle!

please ensure that the box is properly braced. large panels ar more prone to audible resonances.

[s0uljah]

Yash Iv got a pic of the sealed enclosure for this sub, will post for you when i get back home tonight.

[rider60]

okay please do! post it souljah, and LBM ji what should be the port diameter if i go in for the combination of a rectangle and a triangle kind of box, that is around 75liters?

[s0uljah]

For sealed I reckon you should go with approx 40litres

[Sam Kapasi]

As it is you have an underpowered amplifier for a 15" sub.

Now if you put it in a sealed box, that subwoofer will make fun of you.

[s0uljah]

Originally Posted by Sam Kapasi

As it is you have an underpowered amplifier for a 15" sub. Now if you put it in a sealed box, that subwoofer will make fun of you.

He wants ported and to use his existing amp for now. We want him to get a better amp and sealed enclosure

IIRC, rider60 also has a pioneer dvc running on a monoblock in his other car.

[rider60]

well yes and that mono is JBL GTO 301.1 samji, right now i am running low on the $bills and so will upgrade the amp later on!

edit: forgot to mention the sub is 12inch 1200w peak and 400w nominal, DVC from pioneer!, put in a calculated ported box looks similar to shown above!

[nitrous]

Im currently powering the GT4-12 (250rms) with 160W rms and it really isnt worth it.
Ur missing the punch from the sub on the plank because its majorly underpowered.
Feed her 300RMS and then think about the enclosure.

[rider60]

i have a doubt here, by any chance can i use the sony4 channel completely to power this sub? i mean, bridge them to get two channel outs from this and directly connect it to the sub, as it has four pins!, i know this is a svc sub, but will this work or is this a bad idea?

has anyone tried this?