02 BMW 325i porting into the cabin

[DubStyle311 10+ year member]

Hey guys, I am getting my 2002 BMW 325i on tuesday and my equipment is going to be installed next friday.

I have two JL 12w3v2's, each in a separate single sealed box powered by a 600RMS Crossfire amp.

In my old Lexus GS, I got terrible external rattling that I want to avoid this time around. I am really intrigued by the idea of porting into the cabin through the rear arm rest. The 325i has the ski rack option so It should be fairly easy for my installers to do.

This pic has got me really interested

That picture of the JL facing the cabin through the armrest port was really cool, but since I have two speakers it doesnt seem like a logical way to go. What I'm thinking is that since I have each speaker in a separate box, I would have teh rear arm rest ported and have the two boxes on each side of the port facing towards the rear of the car.

Do you think this would provide a nice sized port to equalize some of the pressure into the cabin to reduce some of the external rattle that I am sure I will have.

The alternative would to leave the arm rest unported and have both boxed next to each other facing towards the rear of the trunk.

What does everyone think?

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[Safe_Cracker 10+ year member]

Maybe the idea that p/u's use, a blow through system? Polo..

 

[DubStyle311 10+ year member]

You might as well be speaking a foreign language man. Come again?

 

[ItalynStylion 10+ year member]

I know exactly what you mean. You want bass in the cabin but you dont want the wasted bass in the trunk to shake everything up. I had the same problem with my IS300. I went about solving it by facing two EU700's towards the trunk and porting them through the rear deck. Sounded like magic //content.invisioncic.com/y282845/emoticons/drool.gif.b5e863e893038027711d4402f340dad0.gif

......I blew them two nights ago, God rest their souls //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[DubStyle311 10+ year member]

I assume you used the stock free air sub enclosure as the port?

I had that going with the GS, a little 10 inch opening. It didnt do all that much. I imagine using the entire arm rest will be quite different.

Also, I'm not talking about porting the boxes into the cabin. The boxes are sealed. I just want the cabin and the trunk to have a nice passthrouh.

 

[ItalynStylion 10+ year member]

I assume you used the stock free air sub enclosure as the port?
I had that going with the GS, a little 10 inch opening. It didnt do all that much. I imagine using the entire arm rest will be quite different.

Also, I'm not talking about porting the boxes into the cabin. The boxes are sealed. I just want the cabin and the trunk to have a nice passthrouh.

There are two ports, one running through each of the stock 6x9 locations. I don't really know how you plan to do this using the same box you were using before. I would imagine this would require you to build something different.

 

[DubStyle311 10+ year member]

Im probably using the wrong terminology.

I dont want the subs ported to the cabin. I want the trunk to vent into the cabin through a removed ski pass.

My objective is to gett more volume in the cabin, and hopefully to reduce some of the rattling you hear when outside the car.

I assume at least some of that will happen as opposed to not adding any vents.

Anyone else?

 

[adas Pro Seller]

The ski pass definatly makes a difference, volume wise. But believe me, you'll have just as much trunk rattle ski pass or not. Thats the problem I have, as my trunk lid, fully dynamatted, still flexes 1/2" at the top

You should fire the subs into the skihole if you don't want trunk rattle. I'm thinking of doing the same thing. I'm thinking 2 8's firing ino the skihole, with ports facing up into the 6x9" stock sub location, or, 2 10s sealed firing into the skihole. The only way for no trunk rattle. the bmw trunks are straight gay when it comes to random sounds. from rubber flaps on the air ports on both sides of the trunk, to the plastic rattling, it's a b!tch.//content.invisioncic.com/y282845/emoticons/*******.gif.a649d21efc0d1fd4890a6428166586c1.gif

 

[Safe_Cracker 10+ year member]

http://forum.ecoustics.com/bbs/messages/4/371735.html

Here is how I got my trunk to stop rattling, lol.. Polo..