Circle PORT or Slotted?

Circle port or slotted port. I'm going to lowes in a few hours so I need this information ASAP, if i do slotted port i have to buy 2 sheets MDF, if i do circle i can buy some PVC pipe, which is 6 bucks a pipe.

Your choice, I think... depends on how your box is designed based on where you're mounting it (size considerations) and then which (slotted or round or other) accommodates your sub(s) and your space... have you got a box design? with the c.f. info along with the displacement info of you particular sub(s), etc. you can tune your box port accordingly... if you're just asking aesthetic preference, i've always like round ports...

basics (forgive if they're simplistic), but some might find it interesting:

The most common type of port is a round tube. These are typically made of black plastic and look like a section of thin-walled pipe with a lip on one end.
http://www.carstereo.com/Images/RoundVent.gifThe second most frequently used type of vent is a square port. The advantage of this design is that you are not limited by availability of only certain diameter tubes. You can also build the port out of the same material you are using to fabricate the enclosure.
http://www.carstereo.com/Images/SquareVent.gifThe last type of vent is called a slot port. It is created using one wall of the enclosure as a wall of the vent. This can be very useful for bandpass enclosures which can be very hard to tune to a low enough frequency due to the small size of the front (vented) chamber. Friction created by the air flow in the enclosure traveling along the enclosure wall makes this type of port effectively longer than it physically is - which tunes the enclosure to a lower frequency so a slot port will be shorter for the equivalent vent area when compared to a simpler square vent.
http://www.carstereo.com/Images/SlotVent.gifPorting tips:

Keep the port(s) as far away from the enclosure sides and back as possible except for the slot type port.

Make sure the inside end of a tube or square port is at least the equivalent of one vent diameter away from the back of the box or any bracing materials.

Keep the vent free from anything that may affect air flow through it.

The port should also be placed as far away from the speaker cone as practical.

I do have a box design, the measurements are 30x30x16, this is for 4 12's. 7.8 cubic foot, too big? tuned to 34 Hz. Should be dang loud. Gimme your input.

i think if your going to buy a 18' XXX you should get something better than the hifonics brutus, go for zapco, crossfire, trutechnology, or something of that class, you'll be glad you did
the reason for this is because i know many peopel that use hifonics amps, and recently they as reliable as their amps awhile ago, a few of my friends got the nemesis and brutus amps, and they broke down a little over a month after my friends got it.. but other than that good luck on your XXX it'll sound bombass when u get the right amp/box

First off something must have been wrong in that setup because the brutus amps hold up VERY well most people have theirs for a long time. And plus not everyone has a million dollars for amps and you can get a bx1500d shipped for 275 with a 1 year warranty....hifonics makes good amps....maybe not for sq...but definately durable.

First off something must have been wrong in that setup because the brutus amps hold up VERY well most people have theirs for a long time. And plus not everyone has a million dollars for amps and you can get a bx1500d shipped for 275 with a 1 year warranty....hifonics makes good amps....maybe not for sq...but definately durable.

No such thing as an SQ/SPL amp. It is all in setup