View Full Version : Port Size Differences

05-14-2003, 05:16 PM
Ok I built my 4.60 internal Cu Ft box for my Kicker 15L5 I made it a slot port with the size of the port being 9 inches high and 2 inches wide the port wall is about 4.5 inches long and calculated on the port tuner it was tuned to 37Hz. According to the kicker booklet it say that a 4.5 Cu Ft box should have a 16.25 high port and 3 wide with the wall being 14.75 inches long. I calculated that and it also says that the box is tuned to right at 36-37Hz. My question is does the size difference between my port and the recommended port make a difference on SPL? Since they are both tuned to the same I didnt think that it would make that big a difference but I just wanted to make sure. Also once I break this sub in will the SPL increase and the Frequency range? Thanks for the help.

Randy Savage
05-14-2003, 05:26 PM
The only real advantage of having a bigger/longer port is it will cut down on port noise...

Breaking in the sub won't really affect anything, the suspension won't change, so 'breaking it in' won't loosen it up or create any more throw or anything to that extent...

05-15-2003, 07:41 PM
Originally posted by snova031
The only real advantage of having a bigger/longer port is it will cut down on port noise...

do you mean what you see, that height...... or the depth of the port?
Cuz i thought the more sqr the port, the less port noise

Randy Savage
05-15-2003, 07:42 PM
Originally posted by Jmac
Breaking in your subwoofer will just reduce your chances of damaging it with high power levels ... Not really...it won't do much...

Think about it, people think it will loosen the suspension, but it really doesn't. The suspension is made to stay how it is.

Randy Savage
05-15-2003, 08:23 PM
Originally posted by Jmac
The mechanical components have to stretch before they can perform to full capability (i.e. Spider, surround)

Ok, well, a small enclosure woofer is going to have a stiff suspension (which raises the Fs in most cases, and results in added mass to drop the Fs)...that suspension is going to stay stiff, so a break in won't affect much...

Breaking in really doesn't do much...it's been proven time and time again...

Randy Savage
05-15-2003, 08:28 PM
Josh doesn't. ;)

05-16-2003, 01:36 PM
i think it all comes down to WHAT YOU BELIEVE.. Experts (jlaine and loyd) have both sides of the coin on this topic.. So i believe it has yet to be proven, but moreso what people think is right. I believe in "breaking in", there's no harm in spending a few hours just letting it do it's thing. its not like it's gonna kill you to break em in

05-16-2003, 05:29 PM
That's pretty true, I personally dont "Break in Subwoofers". Like snova said the suspension shouldn't change... on a good speaker. Now if you get a cheap speaker made of cheap products then the suspension might undergo a slight change but not enough to effect the power handling. And even if you "Broke in the Sub" lossining it wouldn't do anything but make it eisier to reach it's Xmax and once you start hitting that you are clipping which is the fastest way to kill a speaker. Of course Circut City told me to break in the Sony Explodes that i bought when i was first starting my audio adventures but when i finally smarted up and went to a specialty store they told me that breaking in speakers isn't necessary as long as the box and amp are tuned correctly. I don't know about u guys but i trust my car audio specialty store. There is also a small section in the book, Loudspeaker Cookbook 6th ed. on breaking in speakers. And yes it would kill me to break them in cuz i wanna know what they are capable of right out of the box, i couldn't listen to a sub knowing that i am not pushing the limits of it. Sorry didn't mean to write that much.

05-16-2003, 06:02 PM
[QUOTE]Originally posted by snova031
[B]The only real advantage of having a bigger/longer port is it will cut down on port noise...

what he said i would go with ur 2nd demesions think it will give better result

05-23-2003, 06:13 PM
Go with the larger port. From my experience, depending on your power, the bigger the port the better for SPL to a certain extent. I started out with 120 inches of port in my comp box and ended up with 150...each increase yielded a little bit higher DB number. Port noise could be an issue also with that small of a port for a 15'' square woofer. Good luck.