PDA

View Full Version : Port location



neonblack
02-11-2012, 07:56 PM
Where should the end of a round port be inside of an enclosure relative to the rear of the sub for air pressure to flow the best? Should it point in a certain direction (at the sub, at the rear of enclosure, etc.)?

mylows10
02-11-2012, 08:14 PM
are you using an aero port or what kind of round port are you using

neonblack
02-12-2012, 12:16 PM
I think both ends of round port should be flared (for faster air flow) if I'm correct so I'm going to do that. Building a fiberglass enclosure for a 10" sub. I guess port is going to be PVC and at least 4" dia. (like most tutorials suggest) but haven't looked into port material yet.

Moble Enclosurs
02-13-2012, 04:50 AM
You're not looking for maximum air flow, otherwise you can have a port that just blows a lot of air out. You are looking for a coupled compression between the chamber and the environment. That being said, for round ports, the placement in the enclosure is more critical than slot ports due to that coupling needed.
Best to have it as far away from the sub as possible, but a general well known rule is at least the distance of the drivers diameter away from the source. And loaded around the corner of the enclosure with another general rule of having the port at least the diameter away from any given obstacle, such as walls, bracing, magnets, etc. This induced the loading more effectively, and relies less on pressure for more output.

pressure and intensity are separate factors of output. One involves air movement at a variable rate depending on physics of the environment, where the molecules can and will be moved around in many directions, and one invokes the manipulation of those air molecules by compression and expansion rather than point a to point b. Its the compression and expansion that causes intensity. The higher rate of compression and expansion, the more intense. This can be done even without blowing around air.

So, focus on that when dealing with port placement.

hispls
02-13-2012, 04:54 AM
^^^^ This.

cliffs. Keep port as far away from anything (box walls, woofer) as you can. Where the port fires into your cabin will likely make more of a difference assuming you don't totally crowd the port anywhere.

kushy_dreams
02-13-2012, 03:50 PM
very useful information itt

Buck
02-13-2012, 03:53 PM
Try to keep the opening of the port inside the box as far away from the woofer as you can. Most of the time, as long as your not right up on the port, you'll be fine. If you want to run it by me when you decide what you want to do, I'll give you my 2 cents.

kushy_dreams
02-13-2012, 04:50 PM
Just out of curiousity, what do you guys think of this in terms of port placement or design flaws?

http://carphotos.cardomain.com/ride_images/3/109/1749/25270874050_medium.jpg

http://carphotos.cardomain.com/ride_images/3/109/1749/25270874049_medium.jpg

It performs great, I'm just looking for any areas I can improve on.

Buck
02-13-2012, 04:52 PM
Good for the situation.

Moble Enclosurs
02-14-2012, 06:07 AM
Just out of curiousity, what do you guys think of this in terms of port placement or design flaws?

http://carphotos.cardomain.com/ride_images/3/109/1749/25270874050_medium.jpg

http://carphotos.cardomain.com/ride_images/3/109/1749/25270874049_medium.jpg

It performs great, I'm just looking for any areas I can improve on.

its tough to give acoustical advice on a physical structure without knowing anything about it, but to make it simple......look at my store on my website and check out the round port enclosures. The way you did it is pretty identical to how I design mine, so your doing something right.

kushy_dreams
02-14-2012, 02:04 PM
its tough to give acoustical advice on a physical structure without knowing anything about it, but to make it simple......look at my store on my website and check out the round port enclosures. The way you did it is pretty identical to how I design mine, so your doing something right.

Ok thanks for the feedback from you and Buck, I really appreciate it. I'll take a look at your page.

The box is about 1.85-1.9cu/ft, tuned to about 32hz with 2 3in pvc's.

Heavylifter
02-14-2012, 02:49 PM
That looks good and efficient

Louisiana_CRX
02-14-2012, 03:22 PM
should bump

kushy_dreams
02-14-2012, 03:30 PM
I'm glad to see all the positive feedback. I'm doing a box for a 15 that is basically the same design. Should be right around 3 cubes tuned to 30-31hz with 2 4in pvc's.

This is how it currently sits:

http://img576.imageshack.us/img576/5565/img20120214142515.jpg



Sorry op, not trying to hijack your thread, but maybe this will give you some more insight.