Weird-Interesting- Port Question

[JCivicHb 10+ year member]

OK i have a question about ports. If i need two subs to share one port, and say, this port is in the middle of both subs, and is 3 inches wide, can i make like two L ports that are both 3 inches off the bottom of the box? I need to know because my port is too long, so i was wondering if i can split it like L and a backwards L port. I know this might not make any sense, ill try to post a pic when i get home, sorry, but if anyone gets it, will this work??

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[skmfkr 5,000+ posts]

like this you make like a T shape?

 

[JCivicHb 10+ year member]

yea kinda, basically the port is longer than how tall the box is so it splits left and right, but keeps same width and everything, do u think it will work?? i wish i had a pic maybe ill make one

 

[skmfkr 5,000+ posts]

i dont understand how your port is taller than your box

 

[req 5,000+ posts]

if the depth of your box, is smaller than the depth of your port. yes, you can run the port along the back of the box in eaither direction. but both subs SHOULD NEVER "share the port" when the port is in the middle, and bent along the back of the box. put in a center "divider" and do two seperate ports 1\2 the width of your origional specifications. but remember, you need to account for displaced volume from the center divider (shouldnt be more than .3 cubes really)

similar to that crappy drawing. all black lines are 3\4" mdf.

and hypothetically, your idea for the port was 2" wide, well as you can see, its split into two ports, both one inch wide, with the 3\4" divider.

 

[JCivicHb 10+ year member]

yea awesome thanks, that pic ^^ was perfect, exactly what i meant. Why shouldnt they share a port? whats the difference between that and having one big port on one side of the box??

 

[drkodin 10+ year member]

yea awesome thanks, that pic ^^ was perfect, exactly what i meant. Why shouldnt they share a port? whats the difference between that and having one big port on one side of the box??

I think what req was hinting at was when the two smaller ports join together to form a larger port the air coming from each side is directly opposing the other. Some people believe this will cause airflow and therefore SQ issues.

I thought about doing this sort of port for a long time, it just seemed like it would look cool to me. After asking a lot of question and figuring out how i was going to do it, req's point of view starting popping up from more than 1 reputable member. In the end it was a draw, just as many people believed it would cause a problem as those who didn't, however all but one was just speculation: http://www.betteraudio.com/geolemon/quadiso/QuadIso.htm

Geo is the only one who i talked to that had actually built the same type of box, and he was without a divider with no ill effects. On the flip side, geo is geo and quite knowledgeable when it comes to these things so just because he didn't have any problems...

I personally didn't do it because the port is purely for looks, going with the traditional shared port on the side saved a lot of box and trunk space.

One last thing to mention, as you were incorrect in your first post, if the shared chamber is 3" wide, then the individual chambers will be 1.5" each. They are actually two seperate ports and need to be designed that way, they will just simply join together at one point. If it helps to understand, picture a 2 dimensinonal (no actual volume just a divider) running between the ports in the shared chamber, then each port will be 1.5" from beginning to end.