Port placement directly behind the sub

colemanyoungerinalaska · Sat Jul 25, 2009 1:52 am

anything wrong with doing this ive already built the box havent ported it yet was thinking about putting the sub on one side and the port behind it there will be a few inches between the sub and it.

colemanyoungerinalaska · Sat Jul 25, 2009 2:01 am

ok i just read that its basically only good for spl is this true if so i think ill do the port on the top and the sub on the side or both on the same wall

Bwcad1 · Post by **Bwcad1** » Sat Jul 25, 2009 6:12 am

thats not entirely true a lot of speakers have ports to the rear. Check out alot of your home audio speakers infinity jbl and a few others all port to the rear.

MobileAudio219 · Post by **MobileAudio219** » Sat Jul 25, 2009 9:08 am

Bwcad1 wrote:thats not entirely true a lot of speakers have ports to the rear. Check out alot of your home audio speakers infinity jbl and a few others all port to the rear.

I thought a straight port directly behind the subwoofer would make it unload (basically like a huge leak?)

And wouldn't that cause some cancellation issues?

I'm not doubting the Great Bill O'mighty

, I'm just wondering...

Bwcad1 · Post by **Bwcad1** » Sat Jul 25, 2009 9:29 am

im not going to get started on standing waves and cancellation here because there are to many people that will argue with me about it, i always thought the same thing but obviously i was wrong. I can go snap a couple pictures of my infiity's and JBL's with rear ports.

but when you think about it just because a port is directly behind the sub doesn't mean its gonna unload. the port diameter would have to be larger than the magnet assembly and at least half way up the cone. The spl guys are running this is fact by the way. 16000 to a pair of 12's directly in front of a 6in or bigger aero.

audiobass10 · Post by **audiobass10** » Sat Jul 25, 2009 11:20 am

Bwcad1 wrote:im not going to get started on standing waves and cancellation here because there are to many people that will argue with me about it, i always thought the same thing but obviously i was wrong. I can go snap a couple pictures of my infiity's and JBL's with rear ports.

but when you think about it just because a port is directly behind the sub doesn't mean its gonna unload. the port diameter would have to be larger than the magnet assembly and at least half way up the cone. The spl guys are running this is fact by the way. 16000 to a pair of 12's directly in front of a 6in or bigger aero.

^ this is very true. works very well in some vehicles, but as always its dependent on your application. Last weekend at the dbdrag event I saw some impessive results using ports back. One in a blazer and one in a crx. Im sure there were many others as well. Alot of times its with external aeros. What vehicle is this in btw?

colemanyoungerinalaska · Sat Jul 25, 2009 1:03 pm

i have 2 sets of house speakers with the port in the rear they are small 4 inch drivers i just wasnt sure how it would sound in a sub. trying to make it sound good with a little bumpage i got the pioneer 880prs about 2 weeks ago have my old focal 165 K2 in the front doors the tweets off of my focal 165hcs in the sails and stock 6x9 in the back. i dont have the focal crossovers hooked up as im using the deck i might install them tomorrow just to see how it sounds and i hae to get rid of all the buzzes in the right door left side is done already
anyways this is in a 03 grand am going in the trunk the box is 13.5 x 13.5 x 21.25 so it should be 1.5 ft3 after sub and port displacement. one 3 inch port going to be tuned to 30hz. made for 1 ten i havent decided which i have a few that all would work so i figured id try them all out til i found which one i liked best

MobileAudio219 · Post by **MobileAudio219** » Sat Jul 25, 2009 2:09 pm

There are so many weird tricks when it comes to spl, it literally makes me want to punch a dwarf.... just because I don't pick on people my own size!

NorthQuad · Post by **NorthQuad** » Sat Jul 25, 2009 2:44 pm

I'm ported to the rear.

colemanyoungerinalaska · Sat Jul 25, 2009 3:46 pm

NorthQuad wrote:I'm ported to the rear.

hows that working for you