need help with slot port
09-21-2006, 04:25 AM
#1
0 Watt CAFz'r
Thread Starter
Join Date: Aug 2006
Posts: 36
need help with slot port
well, i take it that slot ports are the way to go... havent seen anyone messing with round ports... so yeah. we wont go there.
ok, the sub.. RE SX12, the info i was able to find on the ideal port size is:
25" sq. port, 25.5" long. thats for a 2 cu/ft box. so far, my calculations end up with a box that is 13" high, 35" long, 13.5" wide. the sub displaces .16 cu/ft, the port is .48 cu/ft.
now comes my dilemma... lol... :P
given the box is long, it will need to rest against the back wall of my cab (pickup truck) to give me clearance, since i drive a standard. my idea is to have the sub face foreward... and the size of the box obviously wont allow a foreward port as well... so, my idea to solve the problem, is to have 2 exits for one port. is that recommended? i figure having a port exit on either side of the box at the bottom/rear would do (would exit behind each seat). the main port would be about 12" x 2.1", so each exit must be 6" x 2.1"
ok now, if i do that, how do i determine the length needed for the port? is it really that picky of an issue? or is it something i can adjust on my amp? and will this design even work, or is it just gonna sound like crap?
im sure somebody here must know what im talking about
ok, the sub.. RE SX12, the info i was able to find on the ideal port size is:
25" sq. port, 25.5" long. thats for a 2 cu/ft box. so far, my calculations end up with a box that is 13" high, 35" long, 13.5" wide. the sub displaces .16 cu/ft, the port is .48 cu/ft.
now comes my dilemma... lol... :P
given the box is long, it will need to rest against the back wall of my cab (pickup truck) to give me clearance, since i drive a standard. my idea is to have the sub face foreward... and the size of the box obviously wont allow a foreward port as well... so, my idea to solve the problem, is to have 2 exits for one port. is that recommended? i figure having a port exit on either side of the box at the bottom/rear would do (would exit behind each seat). the main port would be about 12" x 2.1", so each exit must be 6" x 2.1"
ok now, if i do that, how do i determine the length needed for the port? is it really that picky of an issue? or is it something i can adjust on my amp? and will this design even work, or is it just gonna sound like crap?
im sure somebody here must know what im talking about
09-21-2006, 08:14 AM
#2
50 Watt CAFz'r
Join Date: Apr 2006
Posts: 87
It does matter, ports are tuned. they act almost like a 2nd woofer. What does it say the box is tuned at in the specs that they give you, If it doesn't say I can put the ts paramiters into my comp and give you a better port dimention
09-21-2006, 06:10 PM
#4
0 Watt CAFz'r
Thread Starter
Join Date: Aug 2006
Posts: 36
the port was tuned to 33hz, if i remember correctly... i'll double check on that one though. the measurements were 25 sq" x 25.5" long.
i guess i could do a top exit port, id have to put a 90* angle in it, but that would be no problem. when theres an angle in a port, how do i measure length? do i measure the baffle side, or the box side?
sorry for all the questions, just wanna get it right the first time
i guess i could do a top exit port, id have to put a 90* angle in it, but that would be no problem. when theres an angle in a port, how do i measure length? do i measure the baffle side, or the box side?
sorry for all the questions, just wanna get it right the first time
09-23-2006, 05:38 PM
#7
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Thread Starter
Join Date: Aug 2006
Posts: 36
what now?? lol...
ive decided to go with round ports. 2 x 3" round ports should do the trick... i picked up the flares and everything. just need to build the box now......
i figure i'll have the ports tuned higher, since i'll have problems getting low bass in a pickup cab. i figure 44hz might do? i donno, anyone think that'll do?
ive decided to go with round ports. 2 x 3" round ports should do the trick... i picked up the flares and everything. just need to build the box now......
i figure i'll have the ports tuned higher, since i'll have problems getting low bass in a pickup cab. i figure 44hz might do? i donno, anyone think that'll do?
09-24-2006, 04:37 AM
#10
0 Watt CAFz'r
Thread Starter
Join Date: Aug 2006
Posts: 36
ok now, if i were to tune it to 33hz, i might run into some problems...
ive been going by this port tuning calculator, it says, if i build a box, approx 1.7 cu/ft inside displacement, after the addition of a sub and ports... to tune it to 33hz, i need 19.69" port length. i put in 2 ports @ 3" diameter. does that mean i need 2 ports @ 19.69", or do i just distribute that length between 2 ports?
heres a link to the calculator i use, its the second one down the page.
http://www.carstereo.com/help/Articles.cfm?id=31
ive been going by this port tuning calculator, it says, if i build a box, approx 1.7 cu/ft inside displacement, after the addition of a sub and ports... to tune it to 33hz, i need 19.69" port length. i put in 2 ports @ 3" diameter. does that mean i need 2 ports @ 19.69", or do i just distribute that length between 2 ports?
heres a link to the calculator i use, its the second one down the page.
http://www.carstereo.com/help/Articles.cfm?id=31
Last edited by killercrow; 09-24-2006 at 04:39 AM.
