Has anyone heard of or tried to make a ported box with two ports tuned for different frequencies?? I tried to model it with WinISD, it lets you set two ports but with only one tuning frequency. The idea is a little wild so Im not sure if it would even work, or result in anything valuable.

I've wondered the same thing before. Win ISD is too basic to do anything complex like that (and it can give you screwy numbers if you add too many ports)

My thought (no fact, just presumption) is that ports work on the pressure created by the cubic volume of the port - hence why larger diameter ports need to be longer, because the longer length will allow it to create the same pressure as a shorter length one. The larger diameter is prefered when feeding the subs more power just because of the shear volume of excursion created so there will be less port turbulance.

With that being said, I'm pretty sure that you cannot double tune a single chamber. I think that the chamber will see the average length of the ports. So if you were to try to combine a 4" port and a 6" port it would roughly see two 5" ports (assuming the port pressure can be that easily translated).

That's my two cents.

If you want to try dual tuning with out making a bandpass box, try an ABC box - they essentially have 2 tuning frequencies.

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Are you looking for a box that has two tuning points all the time, like an ABC or vented bandpass, or are you looking for a dual mode box that can be tuned low for the street and higher for competition?

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i've seena box with a set of clarion 10's but the box was 2 chambers each tuned to a dif frequency...it was interesting to listen to, never did see a db rating from it.

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