LoudBimmer Posted November 14, 2013 Report Share Posted November 14, 2013 ok so, for my 2 10's box, which will be 2 CF, with 8" port (pvc pipe) tuned to 35HZ. How long should port be? xmax on 10's is 19mm. Link to comment Share on other sites More sharing options...
Krakin Posted November 14, 2013 Report Share Posted November 14, 2013 Remember that for filleted terminations the effective port length begins and ends half way though each flare. For DIY-flaring check out this site: http://www.subwoofer-builder.com/port-flares.htm Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener. Link to comment Share on other sites More sharing options...
Krakin Posted November 14, 2013 Report Share Posted November 14, 2013 ok so, for my 2 10's box, which will be 2 CF, with 8" port (pvc pipe) tuned to 35HZ. How long should port be? xmax on 10's is 19mm. For in an outdoor environment with no wave reflections or port air velocity obstructions, and no port wall vibrations you would need 49" of 8" diameter straight port. Every thing changes for every vehicle depending on driver/vent orientations, enclosure placement, seats, and the material of the interior (carpet, leather, ect..). Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener. Link to comment Share on other sites More sharing options...
LoudBimmer Posted November 14, 2013 Report Share Posted November 14, 2013 what's the equation for the car enclosures? Link to comment Share on other sites More sharing options...
Krakin Posted November 14, 2013 Report Share Posted November 14, 2013 There is none that will work in more than one car. I say buy an IM-SG and test till you get exactly what you want. You can get by in car audio with slightly lower vent area then suggested by the equations or calculator based off of most car acoustics. Just don't push it too much. How close the port is to the structural walls or the enclosure lower tuning, and having them as a common wall (non aero-port) will lower the tuning even further. Remember having a high port velocity doesn't always mean higher SPL. Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener. Link to comment Share on other sites More sharing options...
alaskanzx5 Posted November 14, 2013 Report Share Posted November 14, 2013 To high of port velocity creates port noise and to low creates a sub that acts like it's in a leaky sealed box. t1500bdcp 2 t2d4 15" 1 t600.4 1 t400.2 1 set p1 tweets singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz. Link to comment Share on other sites More sharing options...
CleanSierra Posted November 14, 2013 Report Share Posted November 14, 2013 To high of port velocity creates port noise and to low creates a sub that acts like it's in a leaky sealed box. I believe this is when port compression will occur, which in turn does as you stated: acts like a leaky sealed box. Im not the one you want to try to troll. Just a fyi for you. Link to comment Share on other sites More sharing options...
kirill007 Posted November 14, 2013 Report Share Posted November 14, 2013 This thread kind of shows why it's almost useless to port multiple 8's or using 8's in a ported setup instead of using a bigger woofer in a sealed box. Thinking is the root of all problems... You ALWAYS get what you pay for. Link to comment Share on other sites More sharing options...
shanesauce Posted November 14, 2013 Author Report Share Posted November 14, 2013 This thread kind of shows why it's almost useless to port multiple 8's or using 8's in a ported setup instead of using a bigger woofer in a sealed box. I see where you are coming from but you also can't tune a sealed enclosure for low low music. - 2012 Mustang 3.7 Manual - Audio under construction Link to comment Share on other sites More sharing options...
kirill007 Posted November 14, 2013 Report Share Posted November 14, 2013 This thread kind of shows why it's almost useless to port multiple 8's or using 8's in a ported setup instead of using a bigger woofer in a sealed box. I see where you are coming from but you also can't tune a sealed enclosure for low low music. Obviously if you want a overexaggerated low end you can port it to a low frequency or choose the proper subwoofer. What is low low music? Sealed boxes can get as low as you want without bottoming out. Thinking is the root of all problems... You ALWAYS get what you pay for. Link to comment Share on other sites More sharing options...
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