Revised Single VCW12 Enclosure

[Clownrock95]

revision 3 here:http://www.stevemeadedesigns.com/board/topic/205097-duel-nvx-vcw122-box1/

revised sketchup file

changed port amount, length, and size (from 2 11" long 3" wide ports to 1 18" long 4" port)

specs:
-about 18 inches of 4 inch pvc with 90 degree turn (useing psp port calculator) (tuned to 30)
-about 1.8 cubic feet after motor and port
-1 12" sub at 1 ohm 1200 watt
-3/4 inch mdf

any advise appreciated

this is my first proper enclosure so i'm hoping it turns out right

[Clownrock95]

anyone want to throw in there 2 cents

[Triticum Agricolam]

You need more port area. Two 4" ports will be sufficient, but you will probably have a hard time fitting them. A slot port may be more easy to implement.

[Clownrock95]

You need more port area. Two 4" ports will be sufficient, but you will probably have a hard time fitting them. A slot port may be more easy to implement.

care to explan according to psp's calculator 1 4"dia 18" long port is what i would need for a tune of 30

not saying your wrong just trying to understand where im messing up

[ckeeler11]

It's not about tuning its about port area. with 1 4" port the port area is very low which will cause high port velocities leading to port noise. You need to increase port area to lower velocities.

[Clownrock95]

It's not about tuning its about port area. with 1 4" port the port area is very low which will cause high port velocities leading to port noise. You need to increase port area to lower velocities.

ah ok that makes sense forgot that was a thing

[Triticum Agricolam]

Yup, what ckeeler11 said.

Your one 4" diameter 18" long port will give you the tuning you want, but its not enough port area to flow the amount of air it should. When you try to push too much air through a port you get what's called port compression. It will eat your output for lunch and generate a bunch of obnoxious port noise. If you were only going to put 300 watts to your sub, a single 4" port would be fine, but that's not what you are going to be doing.

[Clownrock95]

Yup, what ckeeler11 said.

Your one 4" diameter 18" long port will give you the tuning you want, but its not enough port area to flow the amount of air it should. When you try to push too much air through a port you get what's called port compression. It will eat your output for lunch and generate a bunch of obnoxious port noise. If you were only going to put 300 watts to your sub, a single 4" port would be fine, but that's not what you are going to be doing.

thanks for the info thanks to your info im looking at how to design a slot port box now