what are the reasons for porting?
Just higher DB's? or does it help the sound?
a riend of mine says it help the sub from blowing... im not sure about that but...
thanks in advance...
reasons for porting...
i'm not sure if porting a box will keep the sub from blowing, it just allows for more air to move, and higher db... this all depends on what kind of sub you have and whether or not it likes to be ported or not...
if you are going to port the box, figure out what size port you need to tune the box to 30hz... because if the port is too large, the box will breathe too freely and the sub will "bottom out" on frequencies anywhere below the level that the box is tuned to. the larger the port you make, the higher frequency the box will be tuned to...
for example, if you just randomly throw in a port in your box, and as a result it tuned the box to 70hz, then the sub won't perform well with any frequencies that it gets below that number (most r&b/rap/hiphop music has a bass line which ranges from 30-70hz)... but if you calculate the size of the port you need to tune the box to 30hz, then you will find that not only will the sub hit all the low frequencies, but it will also play louder.
before this discussion goes on any longer...
WHAT KIND OF SUB DO YOU HAVE? and HOW BIG IS THE BOX?
cause, like i said earlier, some subs like being ported and some don't...
if you are going to port the box, figure out what size port you need to tune the box to 30hz... because if the port is too large, the box will breathe too freely and the sub will "bottom out" on frequencies anywhere below the level that the box is tuned to. the larger the port you make, the higher frequency the box will be tuned to...
for example, if you just randomly throw in a port in your box, and as a result it tuned the box to 70hz, then the sub won't perform well with any frequencies that it gets below that number (most r&b/rap/hiphop music has a bass line which ranges from 30-70hz)... but if you calculate the size of the port you need to tune the box to 30hz, then you will find that not only will the sub hit all the low frequencies, but it will also play louder.
before this discussion goes on any longer...
WHAT KIND OF SUB DO YOU HAVE? and HOW BIG IS THE BOX?
cause, like i said earlier, some subs like being ported and some don't...
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stretch240sx
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i have JL W0.
i cant remeber the exact CUft of the box but the box is fiberglassed into the spare well in the trunk, if that helps any?
thanks for the help so far, cleared my questions on the whole Fq thing. but what do you mean by bottoming out? like the sub just cant push the note or just wont hit?
i cant remeber the exact CUft of the box but the box is fiberglassed into the spare well in the trunk, if that helps any?
thanks for the help so far, cleared my questions on the whole Fq thing. but what do you mean by bottoming out? like the sub just cant push the note or just wont hit?
Think about how a sub works, it makes sound by moving in and out as a piston, thus displacing air. In a sealed box, the only air being displaced is on the out-stroke. Ported boxes allow the user to take advantage of the in-stroke as well, by letting the air displaced by the in-stroke combine with the air displaced by the outstroke. Tuning boxes is done by varying the length of the port. For any box with the same port area (L x W for rectangular ports and PiR^2 for round ports), the longer the port, the lower the tune. If you have a sub that can displace a lot of air, you'll want to have plenty of port area, but as ayjay said, too much port area can hurt and cause the box to become and infinite baffle design. This is only a factor when very large boxes and extremely large port areas are used. i.e. 8cubes. and 350sq.in of port.
As for bottoming out, a sub's mechanical power handling becomes a factor the lower you play below your box's tuning frequency. The port is no longer in control of the sub's play because the frequency being played is too low for the port to function, resulting in bottoming out in many cases.
As for powerhandling, small sealed boxes are the best for high power-handling, because they require the most power for the sub to reach its limits. Large sealed boxes are next in line, followed by small ported boxes. As any box, sealed or ported, gets bigger, efficiency goes up. The more efficient a sub in a certain box becomes, the easier it is to reach its limits and the lower the power-handling becomes. This is not a bad thing, it is actually a good thing because this means you'll need less power for a given volume.
Hope that helps you out a little bit.
As for bottoming out, a sub's mechanical power handling becomes a factor the lower you play below your box's tuning frequency. The port is no longer in control of the sub's play because the frequency being played is too low for the port to function, resulting in bottoming out in many cases.
As for powerhandling, small sealed boxes are the best for high power-handling, because they require the most power for the sub to reach its limits. Large sealed boxes are next in line, followed by small ported boxes. As any box, sealed or ported, gets bigger, efficiency goes up. The more efficient a sub in a certain box becomes, the easier it is to reach its limits and the lower the power-handling becomes. This is not a bad thing, it is actually a good thing because this means you'll need less power for a given volume.
Hope that helps you out a little bit.
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stretch240sx
- Posts: 624
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Quote »The more efficient a sub in a certain box becomes, the easier it is to reach its limits and the lower the power-handling becomes[/quote]
ok so if you put a sub in the a box that it is best suited for you wont need a lot of power to push it?
ok so a ported box isnt always the best no matter what sub?
so lets say i got to my shop and ask them to find a port that would tune my box to , lets use ayjays example, 30hz, it might not sound as good as my sealed box?
thanks again, you really answered a lot of questions.
maybe this should be stickied???
ok so if you put a sub in the a box that it is best suited for you wont need a lot of power to push it?
ok so a ported box isnt always the best no matter what sub?
so lets say i got to my shop and ask them to find a port that would tune my box to , lets use ayjays example, 30hz, it might not sound as good as my sealed box?
thanks again, you really answered a lot of questions.
maybe this should be stickied???
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InstantRice
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stretch240sx
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- Joined: Thu Aug 15, 2002 2:30 pm
thanks for the backup K-Mart, i was just kinda going off about it...
but anyways, if you're runnin a JL W0, then don't bother porting it. that sub doesn't move much air, and you wouldn't benifit from porting it.
so in other words, those subs are pretty punchy, and you'd loose a lot of that "punchyness" if you ported it.
but anyways, if you're runnin a JL W0, then don't bother porting it. that sub doesn't move much air, and you wouldn't benifit from porting it.
so in other words, those subs are pretty punchy, and you'd loose a lot of that "punchyness" if you ported it.
InstantRice wrote:depends on what you mean by sounds good. Ported box's in general arent as accurate as sealed. They arent exactly sound Q champs.
keyword.........in general...........
i've heard a fair share of ported boxes that sound great.......its all a product of the driver and box design..........
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stretch240sx
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