help with box.

[Juice0723]

Hello, I have 2 3"diameter ports that are 8.75" long. I figured my box was about 1.9-2.0cuft thats after displacement. I was wondering what the tuning was for this. I figured that it was around 22hz. I did this by adding both the port lengths together and saying its one port in a tuning calculator. Does that work saying its one port?. and this box is for two 10" subwoofers. Could I put one of my blown subs in the other hole and use the one sub?

[smgreen20]

I'm not sure what the correct freq would be, but I know it's not the 22Hz you guesstamate. The lower the freq in general the longer the port then when you add another port it gets even longer.

In theory you could use the damaged sub as a passive radiator but in the end it's not designed for that and would be torn apart over time as well as damage the good sub.

Best bet is to cut out a piece of wood big enough to cover one of the sub holes and/or one of the 2 ports. Apparently you have access to a port/box program, so go w/that. Best solution, build or buy a new box.

[Juice0723]

thanks for the info. I am using the12volt.com's port length calculator to come up with the tuning. So when you keep adding ports the tuning becomes lower or do you need one port that is long to make it lower? I am going to build another box soon anyway. I was just wondering about this box.

[brenzbmr@sb]

if you are to add a second port into the mix you need and keep the same length as the first one then you will tune higher.

golden rule is if you started with a port that was 8 inches long and you wanted to add a second one into it and keep the same tuning then simply
double the length and make both ports the longer length. in this case 16 inches long. now this is only if you are putting this in the same volume of air.

second just cover the hole with a board.
keep in mind that if you do that the sub that still works is now in a larger enclosure..

[Juice0723]

ok thanks