port called for WAY to long?

[lithium]

WINisd just told me i need a 5L box with a 2" port thats 2m long......can the port be outside the box? if not i don't see how it's physically possible......

[mikebw]

You can run the port out any way you want, down the stairs or up the chimney if you have to, but that certainly sounds ridiculous.

What diameter port have you chosen? 12"?

Try making it smaller.

> WINisd just told me i need a 5L box with a
> 2" port thats 2m long......can the port
> be outside the box? if not i don't see how
> it's physically possible......

[Paul O]

That's also an indication you're trying to make the driver do something it doesn't want too, or tuning way too low.

[Pete Schumacher ®]

> That's also an indication you're trying to
> make the driver do something it doesn't want
> too, or tuning way too low.

A 5L box is likely for a very small woofer. A 2" diameter port is overkill to say the least. Use 1" diameter.

[billfitzmaurice]

> That's also an indication you're trying to
> make the driver do something it doesn't want
> too, or tuning way too low.
I agree, a 5L box is appropriate for at best a 4 inch driver, don't even think about running it lower than 80 Hz.

[damkor]

It's not practical certainly. Make the box bigger or tune it higher, to 70Hz, instead of 40Hz. Anytime you try to get deep bass out of a small vented box, the port has to be very long.

[wg_ski]

> It's not practical certainly. Make the box
> bigger or tune it higher, to 70Hz, instead
> of 40Hz. Anytime you try to get deep bass
> out of a small vented box, the port has to
> be very long.

Tuned "high" and it will probably BOOOOOM. Tune lower and lower, and eventually the response converges on what it would be sealed. If you're at that point of diminishing returns, there isn't much difference between sealed and vented, so seal it and be done with it.

[Chris Roemer]

> WINisd just told me i need a 5L box with a
> 2" port thats 2m long......can the port
> be outside the box? if not i don't see how
> it's physically possible......

A 2" dia. port, 80" (2 meters) long will tune a 5 liter (0.18 cu. ft.) box to 24 Hz...

Sometimes in WinISD you can get the "units" mixed up, and while you CAN switch them at random, sometimes ISD gets "confused". Make sure all your units match: in/mm, cf/liters, including the port dia (not in centimeters) and length. Then restart your project and reload your driver.

I know of NO driver that could possibly work in a box that small that could even reach below 40 Hz, much less 25 Hz.

Chris