kryptonitewhite Posted May 16, 2008 Report Share Posted May 16, 2008 I think the statement "keep your port at least 1 port diameter away from any surface" is misleading. If you have a 4"x4" port, remember that if you make a slot port and 1 side of the box is used for a port wall, you add 1/2 the port diameter for end correction, as the air 1/2 the diameter away still acts as if it were port. Now, if your 4"x4" port is 10" long, and you have your enclosure 4" from a hard flat surface, and your box is 20" tall above that, the air after exiting the port then must travel up the 4" space between the enclosure and the surface. (of course, it's prolly not 4" wide as well, but say your port is 32" wide and the enclosure is too....so maybe it's more of a bell effect, or aero effect, but it still needs to be accounted for!) This would make the 4"x4" port that's only 10" long actually another 20", unless the flat hard surface continues on as well, then there's more end correction, adding another 2" (1/2 port dia) With Meade's port being right up against the rear gate, it is elongated...however, it is much wider than the port, so not 100%, but still. So Is he really tuned lower than 27Hz?? IB3 22" Link to comment Share on other sites More sharing options...
Derrick824 Posted May 16, 2008 Report Share Posted May 16, 2008 I think you're over-analyzing it. Link to comment Share on other sites More sharing options...
Boon Posted May 16, 2008 Report Share Posted May 16, 2008 I have found it doesn't make much difference except for pure SPL when yes, especially if the port is very large then the gap between port and surface can act as an extension to the port and lower the tuning of the system as a whole. There's no point trying to calculate it either as trim panels behave rather differently to slabs of MDF 10.x volts fo' life! Link to comment Share on other sites More sharing options...
dwright27 Posted May 16, 2008 Report Share Posted May 16, 2008 i thought meade was tuned to mid 30s?? 2006 F-150 4 DC XL M2 18's Walled Daily Driver XS Power 4 DC 3.5kw Team DC Team S.P.L. Lot of Audio Technix and 1/0 DC Audio Dealer American Bass Dealer XS Power Dealer Audio Technix Dealer Link to comment Share on other sites More sharing options...
kryptonitewhite Posted May 17, 2008 Author Report Share Posted May 17, 2008 27Hz if I'm not mistaken. (so I'm gonna guess factor in in-car as placed, 21.78Hz ) IB3 22" Link to comment Share on other sites More sharing options...
EricM9104 Posted May 17, 2008 Report Share Posted May 17, 2008 27Hz if I'm not mistaken. (so I'm gonna guess factor in in-car as placed, 21.78Hz ) How the fuck are you gonna know just from the pictures? What? You have a little tape measure on your computer that measures the distance between the port and the hatch? 2015 Honda Civic LX 4dr | 24k miles Stock H/U and mids/highs Power Acoustik GW3-12" D2 Sub HiFonics BXX1200.1D @ 1ohm Random 2.5^3' dual ported box NVX LOC Stinger wiring throughout 1977 Chevy SWB Cammed 350 Dual exhaust Cheap Wish stereo Link to comment Share on other sites More sharing options...
AI James Posted May 17, 2008 Report Share Posted May 17, 2008 hes stated before about 34hz hes tuned to Link to comment Share on other sites More sharing options...
Ray Posted May 17, 2008 Report Share Posted May 17, 2008 Absolutely the wall effects his tuning. Trying to figure out just how much is a waste of time imo. It just makes it lower, that and the transfer function works very well for him 2008 California state record holder 157.2 Bassrace2009 California state record holder 157.0 BassraceRollin 50's 158.7db2009 King of Cali Bassrace2009 USACi score 160.5 @ 42hz Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.