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<blockquote data-quote="SPLThunder" data-source="post: 269036" data-attributes="member: 545125">Agreeed, We use a port pretty much to hear the back side of the cone as well as the front. Generally a 3db gain is achieved from just having a port. Wave dynamics is not my thing. I am more interested in electrical engineering. (by the way i am a physics undergrad) However from the professors i have talked to this seems to be my conclusion. When a frequency resonates it becomes very loud in a port however dont you still hear other frequencies even if they arent at a certian harmonic. If a port is tuned to 30HZ the longest wave to resonate will be 30 hz. You will still hear (just not as loud) higher than that even if the end doesnt catch on a node or antinode of the wave.you have to have heard a port &quot;farting&quot; before. This is not good. This is when the speed of air moving in and out in the port moves faster than i think 5% the speed of sound. However when you put you hand in front of a port you dont feel it move in and out at 30 times per second. You feel the &quot;farting&quot; which is not the spl that you want to be hearing. If you could feel the SPL it should be resonating at 30 times per second and only as much as you woofer is moving. It should be equal to the back of the cone. Again this is not my major just how i have come to understand it. If it is not right i would love to be corrected. I always enjoy learning new things.</blockquote>

[QUOTE="SPLThunder, post: 269036, member: 545125"] Agreeed, We use a port pretty much to hear the back side of the cone as well as the front. Generally a 3db gain is achieved from just having a port. Wave dynamics is not my thing. I am more interested in electrical engineering. (by the way i am a physics undergrad) However from the professors i have talked to this seems to be my conclusion. When a frequency resonates it becomes very loud in a port however dont you still hear other frequencies even if they arent at a certian harmonic. If a port is tuned to 30HZ the longest wave to resonate will be 30 hz. You will still hear (just not as loud) higher than that even if the end doesnt catch on a node or antinode of the wave. you have to have heard a port "farting" before. This is not good. This is when the speed of air moving in and out in the port moves faster than i think 5% the speed of sound. However when you put you hand in front of a port you dont feel it move in and out at 30 times per second. You feel the "farting" which is not the spl that you want to be hearing. If you could feel the SPL it should be resonating at 30 times per second and only as much as you woofer is moving. It should be equal to the back of the cone. Again this is not my major just how i have come to understand it. If it is not right i would love to be corrected. I always enjoy learning new things. [/QUOTE]

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