Need slot ported box for brahma mkII 12"

 

Silver Member
Username: Boopers

Lima, Ohio United states

Post Number: 197
Registered: Jul-04
would someone be able to come up with the external dimensions of a box for me if I give you the net volume needed, the displacement of the sub, and the desired tuning freq?

if so: 3ft^3 net, .15 ft^3 sub displacement, and 35hz tune

need to keep the height of the box under 15.5", that's the only restriction I have really
 

Silver Member
Username: Boopers

Lima, Ohio United states

Post Number: 198
Registered: Jul-04
the box I designed in WinISD gave crap results

at max amp output *guessing 2400watts* at 1 meter I get these db results.

Driver : brahma 12
Vas : 38.0
Qts : 0.43
Fs : 28.00
SPL : 84.40
--
Project by : jeremie boop
Project for : you
--
Number of drivers : 1
Box type : Vented
Box size : 3.000 ft^3
Tuning frequency : 35.00 Hz
Vent : 1 vent(s)
13.20 in length for each
2.00 x 13.00 in rectangle



Freq SPL
[Hz] [dB]
20.00 101.35
25.00 109.62
30.00 117.35
35.00 123.32
40.00 123.58
45.00 121.99
50.00 120.85
55.00 120.12
60.00 119.64
65.00 119.31
70.00 119.08
75.00 118.92
80.00 118.79
85.00 118.70
90.00 118.62
95.00 118.56
100.00 118.52
 

Silver Member
Username: Insearchofbass

Post Number: 943
Registered: Jun-04
did you have port whistle? Id bet you did if you were pushin 1200 rms. Which would work against you as well for spl. Do a slot port 13 inch by 4 inch and make it 30 inches deep for a 35 hz tune youll need to make your ports have turns to accomodate the length
 

Silver Member
Username: Insearchofbass

Post Number: 944
Registered: Jun-04
and youll have to account for displacement lost because of the port again
 

Silver Member
Username: Boopers

Lima, Ohio United states

Post Number: 203
Registered: Jul-04
rofl, that's what I need to know, you got the port measurements, now I need the external box measurements.
 

Silver Member
Username: Insearchofbass

Post Number: 948
Registered: Jun-04
15 h x 26.75 w x 23 d = 3.00 cf after displacements external measurements
 

Silver Member
Username: Insearchofbass

Post Number: 949
Registered: Jun-04
that includes port displacement and subwoofer displacement
 

Silver Member
Username: Insearchofbass

Post Number: 950
Registered: Jun-04
using .75 mdf
 

Silver Member
Username: Boopers

Lima, Ohio United states

Post Number: 204
Registered: Jul-04
sweet, little deeper than I'd like, but maybe I can tweak the w and d a bit. got the brahma for 270, 322 with shipping. hopefully it'll be here beginning of next week. probably get here when my shocker gets fixed.
 

Silver Member
Username: Insearchofbass

Post Number: 953
Registered: Jun-04
ill warn you now dont go with a smaller port if you definately dont want port whistle but its up to you
 

Silver Member
Username: Insearchofbass

Post Number: 954
Registered: Jun-04
dont forget to account for the turns which changes the ports length needed for the desired tuning

heres the link you can use to understand how all this is done copy the link and paste in address bar and it will work

http://forum.sounddomain.com/forum/ultimatebb.cgi?ubb=get_topic;f=11;t=060743
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