posted
Hey, I found how big two ports would need to be to tune it how I want to, but I dont have that much space. Here it is...two 4" diameter ports 34.4" long
Now my question is, what would be the proper length and diameter for three ports? Also Does placement for the forts matter, like must they be on the sub side of the box?
Thanks in advance.
Posts: 5 | From: Roselle, IL | Registered: Oct 2002
| IP: Logged |
posted
you can either use a pvc pipe , round , and then use a 90 degree turn so you can fit more lenght . or you could do a slot vent , square or rectangular , out of wood and make that turn 90 degrees to get more length . the lenght of 3 ports would have to be even longer unless you went with a smaller diameter port . usually most people put the port on the same plane as the sub . i heard that its best to do this or you might end up with some cancelation .
Posts: 257 | From: fairport , newyork | Registered: Apr 2002
| IP: Logged |
posted
Could someone convert the port dimensions I gave above into a slot vent or maybe give me a website that does that. One other thing I would like to know is how pvc ports should be sealed.Would a silicone or caulk hold it in place, if so ist there any way to make it look nicer.
Thanks for replies.
Posts: 5 | From: Roselle, IL | Registered: Oct 2002
| IP: Logged |
posted
winisd pro is a pretty good program for figuring out port dimensions and lenghts . do a search on google or yahoo im sure you will find where to download it . sorry i cant remember the site it was on . for sealing the pvc i used regular caulk and then i used rope caulk over that .
Posts: 257 | From: fairport , newyork | Registered: Apr 2002
| IP: Logged |
posted
OK, last thing...I think, lol. Well I gave that program a try, it said with just one port, the legnth would be about 15.75 in. This can't be right, can it? I don't understand how one port tuned to the same as two can be smaller.
Posts: 5 | From: Roselle, IL | Registered: Oct 2002
| IP: Logged |
posted
port length is based on enlcosure volume and port area , height x width of the port for square ports . for circular ports its radius squared x pie , 3.14 . the more port area you have the longer the port needs to be to get the same tunning frequency . you can go with less port area so you can achieve a port length that will fit in your enlcosure , but may come with the exspense of port turbulence , less sq , and less output . ive heard its best to have around 20%-25% of cone area of the sub for your port area for sq and for spl up to 60% .
Posts: 257 | From: fairport , newyork | Registered: Apr 2002
| IP: Logged |
Printer-friendly view of this topic