help me tune

[pj_chevy03]

i am going to make a box for 2 sony 10's. the airspace for both subs is going to be 2.46 before sub and port discplacement. anybody with a box tuning prog. plz see what size ports and length of the ports and number of ports i would need to tune the box to 32 hz. much thanx in advance

[DBfan187]

got the max deminsions?

T/S parameters would help too!

[pj_chevy03]

got the max deminsions?

T/S parameters would help too!

here's box dimensions (external)

height.....................14"
length.....................56"
top depth...............5 3/4"
bottom depth..........8 1/4"
correction on airspace as well.......its 2.16....sorry

T/S parameters
impedance..............4 ohms
d(mm)....................217
d(inch)....................8.5
Rdc(ohm sign).........2.4
Fs(Hz).....................29.7
Qts........................0.45
Qes.........................0.48
Qms........................6.62
Vas(Lit.).................36.6
Vas(Cu.ft)................1.29
Mms(g).....................149.2
Lvc(mH)......................0.9
Xmax(mm)..................7.9
Xmax(inch)................0.3
BL(Tm).......................11.8

whewwwww....hope my comp dont freeze up

[DBfan187]

WHOA! Is this a truck box? If it is, could you draw out the box for me?

[pj_chevy03]

i'll have pics of the box design tonite but i'm not real sure why u need a picture of the box design

[pj_chevy03]

alright jus click on my gallery and it is the first pic.......and the top number is a lil blurry but it is........5 3/4
is that ALL u need to know cuz i'm kinda needin to know soon???????

[DBfan187]

Make your port at the top of the box going straight down. 4" x 2" slot port for 32Hz.


edit* 7.62" long

[pj_chevy03]

Make your port at the top of the box going straight down. 4" x 2" slot port for 32Hz.


edit* 7.62" long

whoa whoa.......what happened to pvc.....but i kinda like your idea better really. are you ABSOLUTLEY sure on those measurements cuz i do not want to make another box.
few questions as well
1. put port in middle of box?
2. include the 3/4" of thickness of wood at top of box in port length?
3. most slot ports i see are huge, why are these so small? is it because of the small size of the box?
4. why is the port length so short?
thanx

[pj_chevy03]

any1 know the above questions????

[packerfan]

Make your port at the top of the box going straight down. 4" x 2" slot port for 32Hz.


edit* 7.62" long

Dont do that, use 4" dia PVC pipe, make it 14" long for at tune of 32hz.

[pj_chevy03]

now i'm confused........someone who knows what the hell they are doinn clear this up

[DBfan187]

Dont do that, use 4" dia PVC pipe, make it 14" long for at tune of 32hz.

WinISD says your way is tuned to 30.76Hz.

Mine is tuned to 32Hz.

[pj_chevy03]

so either way i go it will be tuned in the neighborhood of 30-33 hz
any1 wanna back db up cuz i want to make sure this is tuned rite

[Trixter]

I get a box volume of 2.17cu'

For a 4" round port 12.3" long is 32Hz and for a 4" x 2" slot port 3.76" will produce 32Hz.

Use this very simple formula:

LV: vent length
R: radius of vent (Note: for a square vent R will be the sq.rt of A/Pi)
FB: tuning freq.
VB: box volume in cu"

4" round port:

LV = [(1.463 x 10^7 x R^2) / (FB^2 x VB)] - 1.463R

12.3 = [(58520000) / (3839754.24)] - 2.926

4" x 2" slot port:

LV = [(1.463 x 10^7 x 1.6) / (FB^2 x VB)] - (1.463 x 1.6)

3.76 = [(23408000) / (3839754.24)] - 2.3408

[DBfan187]

I get a box volume of 2.17cu'

For a 4" round port 12.3" long is 32Hz and for a 4" x 2" slot port 3.76" will produce 32Hz.

Use this very simple formula:

LV: vent length
R: radius of vent (Note: for a square vent R will be the sq.rt of A/Pi)
FB: tuning freq.
VB: box volume in cu"

4" round port:

LV = [(1.463 x 10^7 x R^2) / (FB^2 x VB)] - 1.463R

12.3 = [(58520000) / (3839754.24)] - 2.926

4" x 2" slot port:

LV = [(1.463 x 10^7 x 1.6) / (FB^2 x VB)] - (1.463 x 1.6)

3.76 = [(23408000) / (3839754.24)] - 2.3408

Eh, nobody's perfect!