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I went from sealed to ported and have less output?


THEMERQ

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14 minutes ago, THEMERQ said:

Yeah its definitely a sharp turn, I have decides that next box I'm just gonna go with a straight port with no bends, bumping up the size will let me get away with a slightly shorter port length. 

 

I never new having the port too close would do that.

 

How about something like this?

a) addas.PNG.59b88f7a4eaade8d5dd0a0ac55d404b0.PNG

 

b) afdfsaf.PNG.6616ebe7ecf115df7c7052b50537f76f.PNG

A) would work nicely. How far would the external part be from the panel in the vehicle it is facing?

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14 minutes ago, 1point21gigawatts said:

That would be an ideal port placement. 

Sound good then. 

 

Lastly, when adding donuts and round overs to PVC ports is it acceptable to only add half of the round over width to the effective port length? For instance, the "flair" for the port inside the enclosure has a 3/4" round over, same as the port exit, but I only counted half of it on each end for the effective port length. Either way it doesn't make much of a difference, I'm just wondering what you recommend.

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It wouldn’t be half the length of the flare added, that’s crazy. It would be 3/4 inch added. Think about it. There’s a 3/4” thick board in front of the port. Even though it’s rounded over means nothing to what the subwoofer technically feels/sees in reference to frequency. But since it’s a flared port and if you use a regular round port calculator then if that calculator tells you the port needs to be whatever inches long to achieve whatever tuning frequency then you half to add a half inch per flare to that figure. Instead you can jus calculate the length of a port flared on both sides using this calculator.
http://www.psp-inc.com/tools2.html

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95152665-B7FE-41BA-ACAE-2B155FF6E3A9.thumb.jpeg.a810c95490a0726ed7b85e644ed93013.jpeg

This port is flared on both sides. In reference to the enclosure I’m building, on a regular non flared port calculator it calls for a 23 inch length to achieve 32hz. But on a flared port calculator it calls for a 24 inch length to achieve 32hz. I’m confused about what you mean when you say add because of a flare. So I just broke it down to explain a flared port calculation. If you use the correct calculator, like I’ve posted, then there is no need to add any length. On regular non flared ports, here is a calculator to figure that and to reference to the other calculator I posted.

https://www.the12volt.com/caraudio/boxcalcs.asp

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19 hours ago, 1point21gigawatts said:

It wouldn’t be half the length of the flare added, that’s crazy. It would be 3/4 inch added. Think about it. There’s a 3/4” thick board in front of the port. Even though it’s rounded over means nothing to what the subwoofer technically feels/sees in reference to frequency. But since it’s a flared port and if you use a regular round port calculator then if that calculator tells you the port needs to be whatever inches long to achieve whatever tuning frequency then you half to add a half inch per flare to that figure. Instead you can jus calculate the length of a port flared on both sides using this calculator.
http://www.psp-inc.com/tools2.html

Does the radius of the flare matter when using that calculator? What radius do the Precision ports use? I was thinking about going to a larger radius, maybe 1.5"

 

What I meant by half was that Im only counting half of the flare radius and adding it to the total port length. For example the actual PVC pipe length was 22" with a 3/4" radius on each end( the thickness of the board added was also 3/4"). But for the effective port length I only counted 22" + .375" + .375". 

 

gfdag.PNG.fa7184989db477512e41f299571171dd.PNG

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No, it would be 22” + 3/4” + 3/4” = 23.5” of effective port length.

On that precision port calculator just type in the net volume of the enclosure, the desired tuning, the diameter of the port, not diameter of the flares, and how many ports you are using and the calculator would calculate the length accurately.

 

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Like if that port is 32hz when it’s 23.5” long with flares, then for it to be 32hz without flares then it would have to be 22.5” long. And if it only had one flare, instead of two, then it would have to be 23” long to be 32hz. 

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:guido:
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84FE00B4-3F6B-4D93-A95A-040580208716.jpeg.ad3bd6c0313599d5b72f15c44569d74c.jpeg

that’s the effective length of the port. The precision port calculator already factors in the flares when finding a port length. Half an inch per flare is the formula on flared ports and they factor that in. So don’t worry about that. Just calculate on that precision port calculator and when it tells you the length you measure like I posted. Also, you have to type in the “net volume” of the enclosure on port calculators, any port calculator, the port displacement, subwoofer displacements and bracing displacements aren’t included in the net volume of the enclosure. To find the displacement of the port you multiply the radius of the port times the radius of the port times pi, then divided by 1728. Don’t worry about the flares. It is minimal.

:stupid:“How can we help you?”
:guido:
“And don’t forget to tell them that 
the customer isn’t always right.”

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