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jackal wrote:Who does do that in South.
I have my box built, just to tune it.
What is the best all round tuning frequency for a sub box?
jackal wrote:So it is around the correct length of the port.
The box is about 1.7scf and is for a 12" MTX woofer.
I currently have a 2" port about >15" long.
Want to know what should be the correct size for the port length.
I do have a good bass, but I think I can get more with the system.
Note, it is not a competition vehicle just some thing to keep me company, keep me awake and announce my arrival from a distance.
Brian Steele wrote:Not only is the port length too long, but a 2" vent is too small for a 12" car audio woofer. The minimum I'd use is a 4" vent (or if pushed, a 3" properly-flared vent) for a 12" car audio woofer.
kavaninho wrote:Oh well then, port area is your issue!
SR wrote:I have some aeroports i will be putting up for sale soon
jackal wrote:SR wrote:I have some aeroports i will be putting up for sale soon
What is that,? tried searching and only airplane coming up.
To come up by you is a long drive from where I live, bought some separates from you many many moons ago.
kavaninho wrote:Box look a bit small for 1.7cuft per woofer. Or was that that the gross volume using the external dimensions?
Brian Steele wrote:What subwoofer drivers are those?
nervewrecker wrote:Ballpark figure is 12 to 14 inches square for every cubic feet of internal volume.
Work with that and have fun.
It's not a figure set in stone but use it as a guideline.
The resistance of air movement through the port holds back the cone movements. When enough energy is delivered to the coil resulting in enough force generated to overcome the resistance and it no longer can restrict the cone movent the system breaks down and you get a blop blop blop sound meaning it's unloading or bottoming out.
You can play with internal volume, port area and length coupled with power to vary the sound and output over a particular bandwidth.
Less power with larger volume can have better output over a larger bandwidth vs more power in smaller volume. Also not written in stone. Use it as a guide. Driver choice has a lot to do with it here. Use ts parameters as a guide.
Rovin wrote:just as a added note to what nerve said : that 12-14sq"\cuft ballpark guide applies to rectangular\square\other shapes ports but circle ports dont conform to that guide
just google how stuff flows thru a circle compared to other shapes ...
By all means, comment away. Nobody born knowing everything.jackal wrote:Rovin wrote:just as a added note to what nerve said : that 12-14sq"\cuft ballpark guide applies to rectangular\square\other shapes ports but circle ports dont conform to that guide
just google how stuff flows thru a circle compared to other shapes ...
I was thinking the same thing, but not being competent on the topic, I decided to shut my mouth up.
Volume flow rates do differ based on the shape of the ports also based on the size/area, learned that using one of the recommended software in the thread.
Rovin wrote:very 1st type of ports i ever did was circle ports [easiest thing to do-simply put a piece of pipe in a box even b4 i knew what tuning was] , i built many boxes & tried alot of stuff over d yrs that i noticed it a loooooong time ago , research & reading up on d science of it confirms my own real life experiences ...
https://www.youtube.com/watch?v=jN-E1dfMfO0
https://physics.aps.org/articles/v8/94
nervewrecker wrote:By all means, comment away. Nobody born knowing everything.jackal wrote:Rovin wrote:just as a added note to what nerve said : that 12-14sq"\cuft ballpark guide applies to rectangular\square\other shapes ports but circle ports dont conform to that guide
just google how stuff flows thru a circle compared to other shapes ...
I was thinking the same thing, but not being competent on the topic, I decided to shut my mouth up.
Volume flow rates do differ based on the shape of the ports also based on the size/area, learned that using one of the recommended software in the thread.
Few years back I posted a thread right here with the exact same topic.
There was a nice vid rollingstock shared on fb. If I can find it I will share it but seems like you got the jist of things.
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