# w12gti from sealed to ported (can I use stuffing)



## matdotcom2000 (Aug 16, 2005)

Ok.. Here is the point that I am at... I like my w12gti sealed but I want to port it.. been thinking about doing this for a while. I run into a problem though not enough space for the ported box. I can fit around 1.8 cubic inches. I was thinking about tuning it to 29 to 33 hz. The manual calls for 2.25 cubic 
Questions??
1. For the amount of space I am missing would pollyfill be effective into tricking the sub or would fiberglass be better? 

2. Also do you think I would get shuffling if I were to use a 4inch port with this sub a 1000 watts or would 2 3inch ports be better?

PS the sub box would be my center console with the sub facing down and the port (ports) facing forward..


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## matdotcom2000 (Aug 16, 2005)

BUMP


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## [email protected] (Jun 12, 2008)

You would have to calculate the poly in the box design, as just throwing it in there will affect tuning. How to calculate it I have no clue


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## low2001gmc (Aug 27, 2008)

curious what type of vehicle this is going in? polyfill will help but will have to play with it, using different amounts, playing fave type of music and see with how much you like it best. since limited in space, i would use aero ports due to thinner than if making ports out of 3/4 inch mdf.


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## matdotcom2000 (Aug 16, 2005)

This is from a article on pollyfill. 
A few rules of thumb: Stuff small enclosures those with up to about 3 cubic feet of internal volume or less with 1.5 pounds of fiberfill for each cubic foot of internal volume and you should get about a 30-percent increase in box volume without seriously affecting other performance variables. For larger enclosures, add stuffing at a rate of approximately 1 pound per cubic foot and you should get a virtual-space boost of about 25 percent. One thing's certain: You'll impress the heck out of your friends at the art gallery and bistro.


So if that is correct if I have an enclosure that is 1.8 cubic feet and add 2.2lbs of pollyfill the enclosure should then be fooled to be 2.3 cubic feet. Then I would tune the port to that configuration... 

That is my asumption. I want to know from those who have used this method would this be accurate and would it actually work??


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## matdotcom2000 (Aug 16, 2005)

bump


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## Oscar (Jun 20, 2010)

IMO even two 3" ports would be way too small for a W12GTi. I run a W10GTi with 30 sq in. Of port area with a slot port and that's barely enough. A 12 with less than half that area is asking for serious chuffing.


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## matdotcom2000 (Aug 16, 2005)

I figured shuffling will only be a problem if I run the sub over 700 watts per the box building program I used.. 

But the question still stands is pollyfill or lining the walls with fiberglass insulation better?
Also will this actually yeld the sub thinking its in a bigger box?


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## The Baron Groog (Mar 15, 2010)

Polyfil should yield better results for "increasing" box volume. BBP6 allows you to calculate boxes with and without stuffing-though looking at the graph's "just" smooths the tuning hump a bit

Check out KEF ACE speakers-they use activated charcoal in fabric socks and recon it works better than polyfil-available at aquatics stores


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## matdotcom2000 (Aug 16, 2005)

Looking at activated charcoal now


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## jooonnn (Jul 26, 2009)

I used a 4" port for my w12gti and I didn't polyfil it at all. It sounded GREAT. I'm sure some people will call me out on it but I'm sure you'd be hard pressed to tell a huge difference if it had polyfil. The sub was essentially made to play great regardless. Tuning to 33 as opposed to 29 would be hardly noticeable too imo, and the smaller required volume would be much more worth it and it will probably sound a little louder than it would tuned to 29hz.


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## eviling (Apr 14, 2010)

I'd just keep it sealed.


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## owen19 (Oct 21, 2009)

eviling said:


> I'd just keep it sealed.


+1 , it'll sound better than a choked ported enclosure.


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