Slot port vs Round port confusion!!!
11-13-2008, 08:12 PM
#1
0 Watt CAFz'r
Thread Starter
Join Date: Nov 2008
Posts: 27
Slot port vs Round port confusion!!!
Alright, so basically a port is a port is a port, as long as it's built right and tuned properly it'll do the same job either way. What I want want to know is, are there any benefits for one or the other? I think given my new box design (1.3 cubic feet) and 10 inch subs, a slot port would probably be the most "space efficient" way to go, but I'm a total noob with that design, so I'm not really sure that's what I want to do. Any help would be great 
11-13-2008, 09:28 PM
#2
You've got round ports, square ports and vents.
According to a port length calculator website I recently used, vents can be shorter than the other ports, because it uses a side of the enclosure as a wall of the port, and the resonanace makes it act like a longer port.
Round ports can be easily made of PVC pipe, and flared on the ends with things like RF Aeroport ends to reduce port noise, while square ports might be a little harder to build and flare.
It's also easier to build a slot port into the box design, and allow a big enough opening to avoid port noise.
So yes, as you said, slot ports are the most efficient in my opinion.
This might help...
PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES
According to a port length calculator website I recently used, vents can be shorter than the other ports, because it uses a side of the enclosure as a wall of the port, and the resonanace makes it act like a longer port.
Round ports can be easily made of PVC pipe, and flared on the ends with things like RF Aeroport ends to reduce port noise, while square ports might be a little harder to build and flare.
It's also easier to build a slot port into the box design, and allow a big enough opening to avoid port noise.
So yes, as you said, slot ports are the most efficient in my opinion.
This might help...
PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES
11-14-2008, 07:43 AM
#3
50 Watt CAFz'r
Join Date: Sep 2007
Posts: 259
1.3 cubic feet for 1 10? if you're using a slot port you can take advantage of rounding the inside corners with sonotube and resin and forcing the air toward the port.problem is the more you add in the box the more air space you take away. the problem is with a slot port on a small box having it run the whole hight of the box will make it a very small opening when tuning for a good frequency. the bigger the opening the shorter the runner inside becomes. take your measurements and check it out the port calculator, you'll see if you want a port 2'' wide the inside will only be 2 inches long.(exaggerated) the port will only end up being a inch wide. a 3'' round port will probabally be best for one sub in a small box. this is a daily driver right?
11-14-2008, 12:50 PM
#6
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Oh yea, it's definitely a daily driver, lol. I'm not quite on competition level, but at the same time I like to have things done right. I get annoyed with all the idiots who buy random parts and put them in prefab crap and are like OMG my stereo rocks! I'll admit mine isn't the absolute best, but it's none too shabby. Pioneer Premier DEH-P500UB deck and PRS-D1200m amp, with a pair of TS-W257D4 10 inch subs, all run with 2 gauge wire. I've also got a 4 Farad Soundstream cap that I have yet to install, but that's only due to lack of wire. Apparently 17 foot wiring kits don't do so well in a 92 Cadillac that happens to be 17 feet long :P
Anyway, since a round port seems to be the simplest solution for me right now, what about orientation? What would be the best direction to point them. As it stands, I'm planning on putting the subs facing rear like they are now, but even that is easy to change if it'll make a difference in what kind of sound I get inside.
Anyway, since a round port seems to be the simplest solution for me right now, what about orientation? What would be the best direction to point them. As it stands, I'm planning on putting the subs facing rear like they are now, but even that is easy to change if it'll make a difference in what kind of sound I get inside.
11-15-2008, 09:42 AM
#9
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Join Date: Sep 2007
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like i said the BIGGER the opening the shorter the port length. a "short port" gives too much port noise, the deeper into the box the crisper the response, but no closer to the back of the box than the width of the port ( 2inch port, no closer than 2'' from the back of the box) but keep in mind the frequency changes with length. so use the port caculator for help.
Last edited by turboeeyore; 11-15-2008 at 09:47 AM.
11-15-2008, 10:15 AM
#10
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Join Date: Feb 2006
Posts: 16,855
The more port area, the longer it has to be for the same tuning. Among other things, it largely becomes the tradeoff - area for length.
A slot vent is fine - try to keep the length of the opening no more than 6x the width though - ie. something like a 14" x 1" opening is a poor design.
A slot vent is fine - try to keep the length of the opening no more than 6x the width though - ie. something like a 14" x 1" opening is a poor design.
