Derrick824 Posted April 7, 2007 Report Share Posted April 7, 2007 I compete in local spl competitions regularly soo I'm always trying different things to see what kind of difference they make. I'm basically trying to find out what I can do to get the maximum spl out of what I have. The first setup consisted of a pair of RF 12" Punch HX2s in a 4.5ft box w/ a pair of 4" aeroports tuned to 38hz. The subs and ports were all facing the rear and w/ a peak frequency of 45hz I consistently hit in the 145s. I felt that this was a good score for my setup and didn't see any way to gain anymore so I bought another pair of HX2s. The next box consisted of four HX2s facing up w/ 4 4" aeroports facing the rear. This was good for 147s but my peak frequency dropped to 40hz so I felt there was a little more left in it if I could get my frequency back up. Next I changed up the box so that all four subs & ports were facing the rear. This got my peak frequency back up to 45hz and sounds louder than ever to the ear but I'm only reading 143s on the TermLab. I'm a little confused with this. The only thing I can think might be causing me problems is that I had to "flip-flop" the position of the subs & ports in order to fit them all onto one side of the box. There are two subs pushed all the way to the top while the other two are pushed down to the bottom and the same with the ports. Could their positions be causing some sort of cancellation? Right now I'm considering dropping to a lower class and competing with only one pair of subs since I've done better than anyone else in that class. I'm also considering trying out a new box with three rear facing subs & ports. With only three I'll be able to keep everything even across the rear side of the box. So my final questions are; Any ideas what could be holding me back with my current setup? Any ideas that you would recommend me trying with my setup in the future? Thanks. Quote Link to comment Share on other sites More sharing options...
sean 371 Posted April 7, 2007 Report Share Posted April 7, 2007 Not sure what car this is in, but you can try having the port facing up at the very back of the cargo area, reflecting off the back hatch/window. Quote A couple links to some box builds: Tahoe Box 1, Tahoe Box 2, Nissan Titan, VW GTI, Mini-Bump, Hummer H2, Ford F-150 My own car builds (current setup --- under construction): Overall Thread, Kickpods, Dash, Back Doors Subwoofer Wall Link to comment Share on other sites More sharing options...
Derrick824 Posted April 7, 2007 Author Report Share Posted April 7, 2007 Not sure what car this is in, but you can try having the port facing up at the very back of the cargo area, reflecting off the back hatch/window. Its in an '06 Yukon. I've already tried it with subs and ports facing up which was the worst ever at 141db. Quote Link to comment Share on other sites More sharing options...
sean 371 Posted April 7, 2007 Report Share Posted April 7, 2007 Yea, but was the port reflected off the back hatch? I dunno if that would even work, but it's worth a try. Or you could try port forward with the box all the way at the back? Quote A couple links to some box builds: Tahoe Box 1, Tahoe Box 2, Nissan Titan, VW GTI, Mini-Bump, Hummer H2, Ford F-150 My own car builds (current setup --- under construction): Overall Thread, Kickpods, Dash, Back Doors Subwoofer Wall Link to comment Share on other sites More sharing options...
roscoe1129 Posted April 7, 2007 Report Share Posted April 7, 2007 have you considered trying one square port instead of the 4 aeroports? Quote Some people need a sympathetic pat... on the head...with my hammer Scientia est Vox "In Nomine Patris et Filii et Spiritus Sancti" DONT BE AFRAID TO USE THE SEARCH BUTTON!!! SMD SUPER BUYER/SELLER Link to comment Share on other sites More sharing options...
dleccord Posted April 7, 2007 Report Share Posted April 7, 2007 smaller box. maybe try 1.5 cubes or smaller per 12. Quote refs: chode69, superduper Link to comment Share on other sites More sharing options...
sean 371 Posted April 7, 2007 Report Share Posted April 7, 2007 eh, supposedly the bigger the box, the higher the output. So maybe a bigger box tuned higher? Quote A couple links to some box builds: Tahoe Box 1, Tahoe Box 2, Nissan Titan, VW GTI, Mini-Bump, Hummer H2, Ford F-150 My own car builds (current setup --- under construction): Overall Thread, Kickpods, Dash, Back Doors Subwoofer Wall Link to comment Share on other sites More sharing options...
Derrick824 Posted April 7, 2007 Author Report Share Posted April 7, 2007 The main question I have here is how can I lose 2db when I'm doubling my system? W/ two rear-facing 12s I hit 145s yet with 4 rear facing 12s I only hit 143s. How's that possible? Quote Link to comment Share on other sites More sharing options...
David Posted April 7, 2007 Report Share Posted April 7, 2007 eh, supposedly the bigger the box, the higher the output. So maybe a bigger box tuned higher? Smaller Box = more output (look at all the street A,B, and C cars in dbdrag, they have Tiny box's) try putting the subs up with one large slot port in the rear around 150 square inches of port area. I would use a common chamber box around 7.5 to 8 cubes after displacement tuned to 45hz ish, sub up port back, with around 150ish^2 of port area, center the port on the back panel. Quote Link to comment Share on other sites More sharing options...
sean 371 Posted April 7, 2007 Report Share Posted April 7, 2007 Whoops my bad. Mixed it up. Quote A couple links to some box builds: Tahoe Box 1, Tahoe Box 2, Nissan Titan, VW GTI, Mini-Bump, Hummer H2, Ford F-150 My own car builds (current setup --- under construction): Overall Thread, Kickpods, Dash, Back Doors Subwoofer Wall Link to comment Share on other sites More sharing options...
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