[moralfibre]

Originally Posted by navin

The specs of the sub suggest a sealed box. Given the high Qts I would suggest not porting the box. However if you find the box too boomy I would consider an aperiodic vent.

as far as the enclosure goes there are 2 options...

a) increase D1 to say 14-15"
and mount the sub facing up

b) increase H so that the box fit against the rear parcel shelf and D1 to about 6-8" and using a port or 2 to vent the sub directly into the cabin.

Btw this is very good. I amd glad to see someone who is not expecting to be spoon fed.

Hi Navin. If I increase D1 to 13" then I have to decrease D2 to 13" to retain the box volume to 1.213 cu.ft. This will give me a rectangular box. I was of the opinion that a triangular box will sound nicer. Still this is a rough sketch of the box:



I could have tried to increase H but the car is a Santro and the box will end up looking like a floor standing speaker . Dont know whether it would give out proper bass though.

I am glad that you liked my approach. Which of the 2 designs would sound nice?

[low_bass_makker]

Originally Posted by navin

dont use this sub facing up or down. cone sag wil be significant.

However a 30 liter sealed box (about 1 cu. ft) would really give you bass down to Fs and I would also try out Linkwitz EQ on this woofer. It looks capable for such an application.

firstly ->what do u mean by cone sag ?

secondly -> I first made the 1.1 cuft box and played the sub in it. I played very punchy with the help of a sound meter i could see the peak freq was at 50 hz after that it goes down. but when i changed the box volume to 1.65 the recommended vol by the manufacture it sounded very good the lower freq were enhanced very much as much 5db at 40 hz. so i decided to keep the 1.65. This was my part now i just wanna share with u can u help me making a good box which would me more efiicent and flat freq curve or any suggestion u can give to make it play good.

[navin]

Originally Posted by moralfibre

Hi Navin. If I increase D1 to 13" then I have to decrease D2 to 13" to retain the box volume to 1.213 cu.ft.
I could have tried to increase H but the car is a Santro and the box will end up looking like a floor standing speaker . Dont know whether it would give out proper bass though.
I am glad that you liked my approach. Which of the 2 designs would sound nice?

D2 in yor first box was 23". that is huge. it would take up the santro boot. I figured you mgiht want to retain some of the santro's boot (trunk).

a non rectgular box would be ncier as it would support standing waves less. in that respect your first box is almost perfect as it does not many parallel surfaces. you could angle the sides of the box a bit if you really wanted to have no parallel surfaces.

I did not know the height of the car. I would perfer it if the box was less than the height of the rear deck. If the rear deck is 15" from the floor the box should be 15" or less. this is not only cosmetic but alos ensures that teh rear view mirror's view is not blocked.

I would slope the front wall of the box so that it mirrors the slope of the rear seat. this way the box can snugly with the rear seat.

It does look like your first box is inspired by the 21" sub that gunbir and co installed in the RS.

given all this information I prefer your 1st box. i just ownder if you are going to waste any space between the box and rear seat and if you are going to leave enough trunk space for your other needs.

[navin]

Originally Posted by low_bass_makker

firstly ->what do u mean by cone sag ?

secondly -> I first made the 1.1 cuft box and played the sub in it. ...but when i changed the box volume to 1.65 the recommended vol by the manufacture it sounded very good the lower freq were enhanced very much as much 5db at 40 hz. so i decided to keep the 1.65.....

When a heavy cone such as the 250gm cone of your woofer is placed horizontally the suspension (spider) cannot support this weight and evnetually streches and the cone sags. this significanlty changes the characteristics of the sub esp it ablity to play loud cleanly.

I suspected that the publsihed specs are off. Vas looks a bit small and Qts a bit small. Usually in a sealed box we prefer if Vb=<Vas.

just to make sure i tried out a freewre called speaker box lite (v 1.0) and got a VB of 26 liters for a Qtc of 0.5 and a Vb of 10 liters for a Qtc of 0.7 using the published specs.

to arrive a Vb of 50 liters (1.6cu. ft) Vas would have to be 74 liters (keeping other parameters the same) and Qtc = 0.5 for a Qtc of 0.7 Vas would have be 200 liters (keeping other parameters the same).

my guess is that the real parameters esp Vas and Qts are different (in this cases larger) than the published specs or that you like the sound of the under damped box (Qtc < 0.5). There is nothig wrong with the sound. Many like the attack it provides. It requires a stiff suspension (which your diver has) to keep the driver from over excursion. The large Mms would then be required to keep Fs low.

[Bass&Trouble]

Originally Posted by navin

When a heavy cone such as the 250gm cone of your woofer is placed horizontally the suspension (spider) cannot support this weight and evnetually streches and the cone sags. this significanlty changes the characteristics of the sub esp it ablity to play loud cleanly.

Gawsh! I never noticed the Mms on those guys. 250gm cone, maybe it's lead impregnated

And like you rightly mention, since it still has an Fs around 26 Hz which isn't like extraordinarily low, that must be one stiff spider. What a ridiculously inefficient creation.

Couldn't be more right about the sag, Navin. I have an analogy to the situation wrt the human anatomy but I rather not mention it.

[moralfibre]

Originally Posted by navin

a non rectgular box would be ncier as it would support standing waves less. in that respect your first box is almost perfect as it does not many parallel surfaces. you could angle the sides of the box a bit if you really wanted to have no parallel surfaces.

It does look like your first box is inspired by the 21" sub that gunbir and co installed in the RS.

I will have to measure the dimensions of the boot of the Santro to come back to a final reading. Will do this when I see the car in an hour and half.

The box is inspired by this post

I have taken awfully long to decide the dimensions of the box and read a lot and lot of threads before I could think of holding the saw in my hand. The santro plays music without the sub until I carve a box myself.

[kb100]

WOW... Look at this!!

EUREKA EUREKA EUREKA!! ....

Gentlemen!... Presenting...... THE SIX woofer solution!!







IMage courtesy www.bladeice.com / re8fun19

[gunbir]

Originally Posted by kb100

WOW... Look at this!!
EUREKA EUREKA EUREKA!! ....
Gentlemen!... Presenting...... THE SIX woofer solution!!

KB100... Those are RE8's... guess who is the ODM for Resonant Engineering...
our very own Image Dynamics

[navin]

RE makes good woofers. I have heard them. Did not know ID was the OEM. THat install is nice and tame. If were maed a bit shallower it could have fit under a car seat and the bass could have been ported into the cabin.

[Bass&Trouble]

Originally Posted by gunbir

KB100... Those are RE8's... guess who is the ODM for Resonant Engineering...
our very own Image Dynamics

Wow! ID makes the stuff for RE? Impressive. Their subs are rocking. But I personally still prefer the IDs over them.

[navin]

B&T...check out the link KB has provided and this install...
http://www.bladeice.com/install_van/index.html
esp like this one...
http://www.bladeice.com/install_van/pages/0153.html

i wish they could do this to my wife's car!

[Autophile]

Originally Posted by navin

B&T...check out the link KB has provided and this install...
http://www.bladeice.com/install_van/index.html
esp like this one...
http://www.bladeice.com/install_van/pages/0153.html

i wish they could do this to my wife's car!

Since when have you got interested in SPL.

Please note 6 Tru Hammer Monoblocks 1500W at Rs 1 lakh each. Its a simple mathematics to know the expenditure for just for the sub amplification

[Bass&Trouble]

Originally Posted by navin

B&T...check out the link KB has provided and this install...
http://www.bladeice.com/install_van/index.html
esp like this one...
http://www.bladeice.com/install_van/pages/0153.html

i wish they could do this to my wife's car!

Gawsh (again). The XXX series subs are purely orgasmic.

If they did this to my wife's car, she probably wouldnt be my wife after that.

[greatmana2000]

hi navin ,are you a member on www.diyaudio.com ?

[low_bass_makker]

Navin u like this installation very much man but it has got active crossover in it . are they like EQ or they are different than that