[panky12345]

plz lemme know where to find this info navin sir....i wd b grateful.

[navin]

A ported box has be built on the same lines as sealed box. However before you build a ported box you must do the following.

have the exact T/S specs of the woofer (the publised specs are not usually accurate enough)

Get some software like Box Model etc... that will design the Ported box (primarily box volume and port dimensions).

Then build a sealed box (I'd stick to 18mm MDF with extensive bracing) and stick the port in it.

[panky12345]

i assume that ported is nothing but a sealed box with a hole in it, where u put a "Tube-Like" thing (port) of specific dimensions. am i right?

BTW, navin ji, can u plz throw some light on this: are T/S from Pioneer are Ok or should i go ahead and calculate my own T/S from equations given at diysubwoofers.org?

[navin]

T/S parameters must be measured. Very few manufacturers offer accurate published specs. I am not sure how far Pioneer's specs are but be prepared to modify the box to suit.

A ported box looks like a sealed box with a tube in it but requires greater attention to design. In many cases it is usually bigger. There are many solutions that offer decent box design on the net some are Box Model, Speaker Box, and Perfect Box. Most run in DOS or Win 95.

[low_bass_makker]

which woofers do u have panky . and which type r u going o make sealed or ported and the car in which u r going to put them. I will give the size and u can get them made out from fbd

[panky12345]

thanx LBM, they are a pair of 12" premier TS-W126C and i intend to use in Indica

[navin]

these woofers look good. sealed box about 40 liters per woofer is what you need. but they need a big amp. i'd consider 250W per woofer as a starting point.

[panky12345]

i was looking fwd to using in ported box navin....

[low_bass_makker]

for ported box u should have atleast 40-45 liters volume of each sub . If the voulme is less the lower freq will be not be there. so make a box of good volume so that it can sound good. 126C is a good sub it will sound right in a good box if u r going for ported get the ports from manik he has good audision ports for woofer boxes. and try to make the box speaker face rear end of the car it surely help in SQ and SPL also.


http://www.teamrocs.com/technical/pages/aiming.htm

[navin]

without T/S specs it is diffcult to tell what size box would be ideal. atleast a sealed box is more tolerate of such errors. even if i had T/S specs I would use a speaker box modelling software for better results than the guesses taken by me.

[moralfibre]

This is what I have come up with for a 1.2 Cu.ft. enclosure. Used this link

The specs for the sub are:
RevC (Ohm) : 3.0
LevC (MH) : 0.927
Fs (Hz) : 32.3
ZMax (Ohm) : 44.54
Qms : 7.903
Qes : 0.581
Qts : 0.541
Vas (cu.ft.) : 3.062
(liters) : 86.70
RMS (NS/M) : 2.519
MMS (q) : 97.95
Cms (m/N) : 2.484 x 10 -4
BL (T*m) : 10.222
Sd (sq. ft) : 0.534
(sq. m) : 0.0496
HVC (Inch) : 1.276
(mm) : 32
Hag (Inch) : 0.394
(mm) : 10
XMAX(Inch) : 0.44
(mm) : 11.2


Any suggestions to improve the design? Should I opt for porting this enclosure? If yes then what should be the port diameter and length?

[low_bass_makker]

navin i have two 3004 spl woofer. If u dont mind would u suggest me a box of the same i am uploading the pdf file of the woofer t/s parameters for ur ref. Plz if u can suggest me a box for it i wanted a ported one for it. ( sorry for the size of the image)

[navin]

Originally Posted by moralfibre

This is what I have come up with for a 1.2 Cu.ft. enclosure. Used this link
Fs (Hz) : 32.3
Qts : 0.541
Vas (cu.ft.) : 3.062
(liters) : 86.70
MMS (q) : 97.95
Cms (m/N) : 2.484 x 10 -4
BL (T*m) : 10.222
XMAX(Inch) : 0.44
(mm) : 11.2


Any suggestions to improve the design? Should I opt for porting this enclosure? If yes then what should be the port diameter and length?

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.

[low_bass_makker]

did answered mine or panky`s i am a bit confused man

[navin]

LBM, your woofer...
Fs= 27, Qts = 0.32 Vas = 37 liters! BL = 28+ wow...
Mms = 250gms! yikes! dont use this sub facing up or down. cone sag wil be significant.
You can use this in a ported box but I dont think I can trust these specs that much. I wont be surprised if Qts is much higher (above 0.4).

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.