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#1430381 - 04/07/08 09:05 AM

Building a box with a external port

trailz516
SD Ralph Wiggum

Registered: 19/10/07
Posts: 35

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Im looking to build a box and have the port right up to my rear deck which would mean most of the port would be outside the box. Im not sure if tuning frequency will change when doing this. Can anyone help?

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#1430732 - 05/07/08 09:08 AM

Re: Building a box with a external port [Re: trailz516]

only126db
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Registered: 22/01/00
Posts: 189
Loc: CA

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The tuning will change because the area the port takes up inside the box isn't being taken up anymore(box will be larger inside).

The way to figure out the tuning is to find out the air space your port would have taken up in the box then add that to the net cu ft of the box instead of subtracting it.

Then you can rework the length of the port to compensate for the added air space in your box....

Understand?

Not sure if I explained it clearly enough...

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#1431622 - 07/07/08 08:37 AM

Re: Building a box with a external port [Re: only126db]

SuperJay
I made this!!
SD OG Playa

Registered: 30/08/07
Posts: 21214
Loc: SoCal

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it doesn't matter if the port is inside or outside the box, just remember that the port should not be included in box volume.

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#1431956 - 07/07/08 01:49 PM

Re: Building a box with a external port [Re: SuperJay]

93_chevy
sh!t talker...yeah
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Registered: 01/07/02
Posts: 2747
Loc: San marcos, TX

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yeah like jay said it doesnt matter...

if the port is 100% outside of the box you dont have to account for its displacement but is not included in the volume...

if the port is some of the way inside the box only account for the portion of the port that is displacing air inside the box but again, none of the port itself is considered airspace if that makes any sense

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#1432090 - 07/07/08 04:37 PM

Re: Building a box with a external port [Re: 93_chevy]

trailz516
SD Ralph Wiggum

Registered: 19/10/07
Posts: 35

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Thanx for the replies...

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