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View Full Version : Think this will work ot alright?



mendon mafia
05-01-2009, 01:18 AM
first of all i want to know is this still considered a slot port? meaning can I take half the port width off the length to achieve the same tuning

anyone see any problems with the port wrapping around this much? what about having the port directly behind the sub like that?

actual plans are going to be ~2 cubes net 50-60 inches of port area tuned to 32-38 hz. 2 rd alpha's on 2k rms. building 2 separate boxes so i can fit into my vehicle.

any input to get me better numbers while retaining sq i would like to hear. or if i should change something let me know what you think i should change.

(box was drawn in paint and needed to be modified to fit on the attachment's. dont make to much fun haha)

dappa5
05-01-2009, 07:11 AM
26511153give this a try might cut down on turbulance (maybe) srry so crude p m me if you want a propper design (sketchuped etc....)

mazdakid
05-01-2009, 08:41 AM
Is each box going to be 2 cubes with 50-60 inches of port each?

mendon mafia
05-01-2009, 09:28 AM
Is each box going to be 2 cubes with 50-60 inches of port each?

yes that is correct. so in the end il will have 2 12" alphas ~4 cubes ~100-120 inches or port area.

mazdakid
05-01-2009, 10:46 AM
You don't need that much port area for those subs. 16 square inches per cube shouldn't give you any port noise.

mendon mafia
05-01-2009, 03:48 PM
You don't need that much port area for those subs. 16 square inches per cube shouldn't give you any port noise.

im not worried about noise, like i will even be able to hear it over the bass lol.

im going big cuz more port area = more loud. i just want to be sure im not going so big as to damage the subs or lose output or anything else that can happen.

i am still unclear if having the port U shaped is bad

also is it bad to have the rear of the sub firing into the port opening like shown?

dappa5
05-01-2009, 10:40 PM
I would nt fire the subs into the port like that but its yours lol snaking the port will give you a little higher velocity than the u shape but try it anyway who knows you may have just inVENTED the greatest sub enclosure ever seriously though g l w that

mendon mafia
05-02-2009, 01:12 PM
I would nt fire the subs into the port like that but its yours lol snaking the port will give you a little higher velocity than the u shape but try it anyway who knows you may have just inVENTED the greatest sub enclosure ever seriously though g l w that

I pmed you because i couldn't see the pic. it was to small.

But i think i get what your saying about snaking it. basically just make another bend in the port so that it dose not open up to the back of the woofer, correct?

Is that necessary or does having the port open up to the back of the woofer not matter?

would it be better th have more bends and not open up behind the woofer or have less bends and open up behind the woofer (like in my pic)

Im gonna post up better pics of what i think you are talking about so you guys can get a better idea (at least of what is in my mind)

mendon mafia
05-02-2009, 01:17 PM
heres what i was thinking

DonH
05-02-2009, 02:58 PM
bro go here its free and you can make ur box 3d
http://sketchup.google.com/


also i would snake the port like stated before

SicAudio
05-02-2009, 03:36 PM
you dont want the port opening directly behind the sub so of the 2 the right pic is the best. but I think you have 2 much port.

mendon mafia
05-02-2009, 08:50 PM
bro go here its free and you can make ur box 3d
http://sketchup.google.com/


also i would snake the port like stated before

so like the pic on the right then?

what are the ill effects of opening the port up to the back of the woofer like in the pic on the right?

Why does it matter?

wouldn't adding the third bend make the turbulence higher and port velocity lower?

dappa5
05-02-2009, 10:40 PM
dude sorry it took so long to get this to you, but i didn't see your message
give this a look.http://sketchup.google.com/3dwarehouse/details?mid=e12ab4c2b399f57753e3b43bd47066d4
it is 2+ ft3 before port and sub displacements. i made the ports 40 in2 you could bump it a little (3in totaling 48) however this will take away from your volume (bad) since it is my math , i wouldn't gaurantee but this should be tuned around 37-38 hz :D:D
plus this is incredibly easy to build so try it. let me know how it turns out.

dappa5
05-02-2009, 10:42 PM
i only showed it from tht angle so you could see the port but download it to move it around and view from all sides

dappa5
05-03-2009, 01:02 AM
can also buildand ship 2 youif youre willing topay 40 bux 2 ship

dappa5
05-03-2009, 01:25 AM
i see you on here looking what did you think???

mendon mafia
05-03-2009, 01:36 AM
dude sorry it took so long to get this to you, but i didn't see your message
give this a look.http://sketchup.google.com/3dwarehouse/details?mid=e12ab4c2b399f57753e3b43bd47066d4
it is 2+ ft3 before port and sub displacements. i made the ports 40 in2 you could bump it a little (3in totaling 48) however this will take away from your volume (bad) since it is my math , i wouldn't gaurantee but this should be tuned around 37-38 hz :D:D
plus this is incredibly easy to build so try it. let me know how it turns out.

thanks for the sketch. It wasn't so much the plans i was having a difficult time with it was the port alignment and port area that i was more concerned with.

Im also looking for 2 cubes NET (after displacements) so your box is gonna be to small but its not a big deal i already have several sketches drawn up i just need to realign the port so that it doesn't open up to the rear of the woofer (apparently thats a "no no" for some unknown reason)

SicAudio
05-03-2009, 01:37 AM
so like the pic on the right then?

what are the ill effects of opening the port up to the back of the woofer like in the pic on the right?

Why does it matter?

wouldn't adding the third bend make the turbulence higher and port velocity lower?

the speaker and the air it moves doesn't care how many bends it has. the port directly behind the sub makes the sub unload easier which is bad for the sub and the sound.

mendon mafia
05-03-2009, 01:49 AM
the speaker and the air it moves doesn't care how many bends it has. the port directly behind the sub makes the sub unload easier which is bad for the sub and the sound.

finally an explanation, thanks a lot!

that makes kind of sense and was kind of what i was thinking. So it basically just makes it too easy for the sub to push the air in and out of the port correct, making it as if it were in free air? Or is it more of a coupling with the speaker cone and the air in the port over driving the woofer?

Not that i dont believe you but does anyone know from first hard experience that the port alignment i initially drew up wont work well compared to snaking the port as in the second sketch?