Home Theater Forum and Systems banner

Why does port length increase when two ports replace one?

14442 Views 14 Replies 8 Participants Last post by  talunceford
As per title,

Just wondering why two ports are required to be longer than a single port?

For instance if I tune a cab with a single 10" port, but the port velocity is too high and I add another port, these ports are then required to be 22.5" long each?
1 - 3 of 15 Posts
I was thinking of building a sub box similar to the svs with 3 ports, but winisd gives me ridiculous port lengths. How does svs get away with having three ports?
In respect of BKnights comments, I had a play with WinISD last night, and managed to get port lengths to around a meter each with a 15" driver, its still a lot for a box though, and I think a Sonotube would be the only realistic way to build an SVS Ultra type sub with a 15" driver.
I was modeling a dayton 12in hf in a 4.2ft³ and wanted the look of the svs with 3 ports. I like how proportional the box looks in regards to the driver and 3 ports.

but it seems i won't be able to get that look with this sub, guess i'll have to save this look for a 15in driver like the tempest which was more reasonable with three ports
Ill try take a look at the model(s) tomorrow and see if I can come up with anything of use, if no one beats me to the punch.
Thanks I was planning on using the 4 in flared ports from PE which can be up to 17 in long.
Posted via Mobile Device
1 - 3 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.