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View Full Version : one 3" port?



jeremiah
12-29-2006, 01:14 AM
is one 3" round port big enough for a 2cu.ft box for one 12"

jmanpc
12-29-2006, 01:14 AM
i'd do at least 4"

Mr Bojangles
12-29-2006, 01:16 AM
4" port for such a small box?

jeremiah
12-29-2006, 01:20 AM
the sub has a 13mm max

jeremiah
12-29-2006, 01:28 AM
would it have better SPL than my box I have now this is the box I have now
http://www.subwoofertools.com/forum/ported-box.asp?Ew=40&Eh=13&Dia=6&Xmax=13&Vd=.045&NumW=1&Vb=1.75&Fb=27&Qts=&Vas=&Fs=&CE=0

jeremiah
12-29-2006, 01:30 AM
the 3" port will be tuned to 32

Mr Bojangles
12-29-2006, 01:31 AM
yea a little bigger port will improve slightly

jeremiah
12-29-2006, 01:38 AM
so it won't be any louder with the 3" port than it is now

Mr Bojangles
12-29-2006, 01:42 AM
I would say yes it will be louder because it will allow more free air to flow.

How many watts do you have on the speaker first of all?

Mr Bojangles
12-29-2006, 01:43 AM
2cuft is kind of small for a 12" doing SPL

xluben
12-29-2006, 01:48 AM
what the hell is everyone in this thread talking about?!?!?!

i don't think this box is for spl. the slot ported one he linked to is tuned to 27hz, not an spl box!

the linked box has 20in^2 of port area. decent for a 12" but could be more.

a 3" round port has about 10" of port area, waaaay too small. port noise for sure.

raising tuning will increase peak spl (theoretically).

if you want to do round ports, it should be at least two 3" ports, if possible two 4" ports.

if you do a long box like the one in the link you could probably handle the 30" length needed for a 32Hz tuning frequency( with two 4" ports).

xluben
12-29-2006, 01:50 AM
this is probably best/easiest for your situation:

http://www.subwoofertools.com/forum/ported-box.asp?Ew=40&Eh=13&Dia=6&Xmax=13&Vd=.045&NumW=1&Vb=2&Fb=32&Qts=&Vas=&Fs=&CE=0

more port area, slightly higher tuning, larger box volume.

(lower port air velocity, higher peak spl, flatter response)

Mr Bojangles
12-29-2006, 01:51 AM
i think two 4" ports will be a little much for 2cuft man..

exactly what i said about this box not being made for spl.

jeremiah
12-29-2006, 01:52 AM
2cuft is kind of small for a 12" doing SPL

I want SPL and SQ.
the amp is a pg xs2500 700rms at 2ohms

Mr Bojangles
12-29-2006, 01:54 AM
how many rms is your speaker?

xluben
12-29-2006, 01:56 AM
i think two 4" ports will be a little much for 2cuft man..

exactly what i said about this box not being made for spl.

coming from the man with four 3" ports for two 15's :rolleyes:

i have double that port area for two 12's.

try this:

http://www.carstereo.com/help/Articles.cfm?id=31


Driver Size (Inches): 12"
Enter Quantity of Drivers: 1
Enter Xmax (mm): 13
Enter Tuning Frequency (Hertz): 32

Minimum Area: 22.79 in^2

which would be three 3" ports or two 4" ports

if you don't trust that, download winisd and learn how to use it.

also a common rule of thumb for spl applications is 16in^2 of port area per cubic foot of enclosure volume.

Mr Bojangles
12-29-2006, 01:58 AM
coming from the man with four 3" ports for two 15's :rolleyes:

i have double that port area for two 12's.

http://www.carstereo.com/help/Articles.cfm?id=31

Driver Size (Inches): 12"
Enter Quantity of Drivers: 1
Enter Xmax (mm): 13
Enter Tuning Frequency (Hertz): 32

Minimum Area: 22.79 in^2

which would be three 3" ports or two 4" ports

if you don't trust that, download winisd and learn how to use it.

also a common rule of thumb for spl applications is 16in^2 of port area per cubic foot of enclosure volume.

Thought you were talkin about two 4" vented ports

xluben
12-29-2006, 01:59 AM
Thought you were talkin about two 4" vented ports

what the hell are you talking about?

two (2), four (4) inch diameter, round ports, each 30" long.

in a 2 cubic foot (net) volume box, that is 32Hz tuning.

jeremiah
12-29-2006, 02:01 AM
this is probably best/easiest for your situation:

http://www.subwoofertools.com/forum/ported-box.asp?Ew=40&Eh=13&Dia=6&Xmax=13&Vd=.045&NumW=1&Vb=2&Fb=32&Qts=&Vas=&Fs=&CE=0

more port area, slightly higher tuning, larger box volume.

(lower port air velocity, higher peak spl, flatter response)

how mane db's mor than the box I have

Mr Bojangles
12-29-2006, 02:02 AM
if you do a long box like the one in the link you could probably handle the 30" length needed for a 32Hz tuning frequency( with two 4" ports).

thought u meant vented.

xluben
12-29-2006, 02:03 AM
how mane db's mor than the box I have

you are both retarded, i'm going to bed

Mr Bojangles
12-29-2006, 02:05 AM
:laugh:

jeremiah
12-29-2006, 02:21 AM
you are both retarded, i'm going to bed

me to :zzzzz: :drool:

helotaxi
12-29-2006, 08:49 AM
Vented = ported
However, audio terminology > you

/thread