Port Tuning and Port size

[BoxNoob]

I have been reading and google searching to build a ported box. I currently have 2 RE audio 10's in a custom sealed box that I built. They sound pretty good, but I wanted to build a ported box.

I wanted to make the box as small as possible. The sub recommended is 0.65 to 1.0.

So when going to a ported box I read that it depends on the box tuning. Many recommend 33. I read that tuning should be the same on each sub so that there is no cancellation. IF i wanted to tune one box to 33 and another to 42 how would that cancel out frequencies. Why would it not add to the frequencies???

Second question is how big should the ports be. Since this is going to be as small as possible, would a 1 inch x 12inch port be big enough. The port will have to wrap around the sub on the inside.

I might attempt a sketch up if I have a chance.

any suggestions would be great.

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[Beatin' 10+ year member]

from what I understand about ported boxes, size matters.

Both in terms of port size and box size. The bigger, the better.

 

[mlstrass 5,000+ posts]

golden rule for ports is not to go over a 1:9 ratio, so your 1x12 wouldn't be ideal. Might end up with port noise...

 

[BoxNoob]

can 2 subs share the same port effectively or will the port need to be adjusted to compensate for the second sub???

 

[hispls 5,000+ posts]

can 2 subs share the same port effectively or will the port need to be adjusted to compensate for the second sub???

Port area and length is determined by box volume and cone area. a 4" flared port should be adequate. It's acceptable to put a 90 degree bend internally in the port if you need in order to fit it within the box.

Also you must subtract volume of port from volume of the box. If you do not have extra cargo space to spare you're shooting yourself in the foot trying to port a box which is too small. Sealed alignment is far more forgiving if you're trying to skimp on volume.

 

[BoxNoob]

when you say 4inch's is adequate is there a formula that says which port is recommended in size??? The bigger the port the better the sound??? the more sound????

If possible please explain i'm a noob //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I understood the 1:9 ratio for port noise|velocity.

Thanks

 

[BoxNoob]

ok here is a sketch up of the idea I had, please let me know the downfalls

manually calculating area gives me around 2 cubic feet, double checking port length gives me a tuned frequency of approx 30-32

again any suggestions, I know adding rounded corners|corner slats, etc will be needed.

thanks in advance