t-money Posted January 7, 2012 Author Report Share Posted January 7, 2012 i guess i thought the more port area the more output + the fact i calculated the port wrong. looks like surgery tomorrow. thanks guys From what Ive experienced myself, More port area = smaller range you can play(say your tuned to 35hz the more port area you have the smaller the range you can play above and below that), Less port area the larger the range you can play. noted 2002 ford focus hatch pioneer DEH-P8400bh infinity kappa 6.5 components front and rear XS Power D1200 Shuriken BT-100 audioque 120.4 2 15 inch audioque HDC3 D2 2 audioque 2200d big 3 mechman 220a alt with external regulator 479-418-3056 Link to comment Share on other sites More sharing options...
bkolfo4 Posted January 7, 2012 Report Share Posted January 7, 2012 From what Ive experienced myself, More port area = smaller range you can play(say your tuned to 35hz the more port area you have the smaller the range you can play above and below that), Less port area the larger the range you can play. Unless you just get way out of control with port size, you should not be having issues with larger ports limiting frequency response. You may be experiencing the smaller ports not operating correctly and the tuning is actually changing as the air velocity gets too high for the port to operate as designed. This would be the reason you are getting better results below the tuning frequency with the smaller port. If the port is operating correctly, the output below tuning should fall off rapidly. The port size should not be a controlling factor in the upper frequency response either, unless you have created a design with a large output peak at the tuning frequency. This would cause frequencies above tuning to have less output compared to the peak, but this would be related to box size vs tuning frequency, not the port size itself. Current system: 1997 Blazer - (4) Customer Fi NEO subs with (8) American Bass Elite 2800.1s Previous systems: 2000 Suburban - (4) BTL 15's and (4) IA 40.1's = 157.7 dB at 37 Hz. 1992 Astro Van - (6) BTL 15's and (6) IA 40.1's = 159.7 dB at 43 Hz. Link to comment Share on other sites More sharing options...
t-money Posted January 8, 2012 Author Report Share Posted January 8, 2012 well guys i took out the back wall and put in a new port its 7x20x20. it doesnt kill the lows like it used too. but it is 100% better than it was. guess now i need to try to break in the subs a little more. 2002 ford focus hatch pioneer DEH-P8400bh infinity kappa 6.5 components front and rear XS Power D1200 Shuriken BT-100 audioque 120.4 2 15 inch audioque HDC3 D2 2 audioque 2200d big 3 mechman 220a alt with external regulator 479-418-3056 Link to comment Share on other sites More sharing options...
bkolfo4 Posted January 8, 2012 Report Share Posted January 8, 2012 Still tuned around 33 Hz and your net volume has dropped compared to your single sub box. Make that port 26" long and it would be a nice improvement. Brian Current system: 1997 Blazer - (4) Customer Fi NEO subs with (8) American Bass Elite 2800.1s Previous systems: 2000 Suburban - (4) BTL 15's and (4) IA 40.1's = 157.7 dB at 37 Hz. 1992 Astro Van - (6) BTL 15's and (6) IA 40.1's = 159.7 dB at 43 Hz. Link to comment Share on other sites More sharing options...
mlstrass Posted January 8, 2012 Report Share Posted January 8, 2012 Box is way too big IMO... Assuming you have copper coils with a 2200 @ 1ohm on each one, I'd do 8.5-9cubes net, 16^2 port area per cube and tune to 35Hz. You could go a few Hz lower on tuning if you plan to play a lot of stuff in the 20's. Or make a port reducer to drop tuning when playing the low low stuff... Link to comment Share on other sites More sharing options...
Socky Posted January 8, 2012 Report Share Posted January 8, 2012 What ive heard and seen, the aq's dont really like the low lows. You will gain more output on the lows if to a different sub, thats what bigpimpin noticed. Jeep Cherokee 4dr -4.75 in front, new rusty's 4.5 in rear leafs -micky thompson 35x14.50x15 -locker rear -Rusty's offroad Engine/transmission/transfer case/crossmember/gas tank skid plates -Warn front bumper with 8000lb winch -Custom rear bumper -Warrior product tube doors (summertime) -Optima redtop (starter) -26XK miles and still runs like a bat out of hell Kenwood H/U 1/0 wire, 136 amp alt 200 ah batteries 12.7 daily 2 Apsm 1500 @ 2 ohm strapped on zv3 d1 with ns softparts Mb quart 125.4 wired to 4 aura 6's 3.6 cube box tuned to 36 plays down to 23hz Link to comment Share on other sites More sharing options...
bkolfo4 Posted January 8, 2012 Report Share Posted January 8, 2012 He is comparing it to the AQ sub he already had. He had one and added a second. . . Current system: 1997 Blazer - (4) Customer Fi NEO subs with (8) American Bass Elite 2800.1s Previous systems: 2000 Suburban - (4) BTL 15's and (4) IA 40.1's = 157.7 dB at 37 Hz. 1992 Astro Van - (6) BTL 15's and (6) IA 40.1's = 159.7 dB at 43 Hz. Link to comment Share on other sites More sharing options...
Torres Posted January 8, 2012 Report Share Posted January 8, 2012 Can someone tell me how the calculator got the port volume? It says .30 cuft. An 8x8 port 3" long (2.25 internal which I see it knows) would be 9.5 x 8.75 x 2.25 = .108 cuft. It throws off the net volume a little. Not a lot in this case, but like I said above I have seen several times where it gets off pretty good on L ports. the calculator takes end correction into port volume. so (2.25 + 4) * 9.5 * 8.75 is what it uses for the port volume. if the number in common port walls was 0, it'd use 9.5 * 9.5 * 2.25 which would come up with .12 Link to comment Share on other sites More sharing options...
bkolfo4 Posted January 8, 2012 Report Share Posted January 8, 2012 Interesting, I have never seen anyone use end correction as part of the port displacement. . .end correction is just a calculated effect caused by friction against the adjoining wall, not really a displacement from the airspace. Another thing I have found actually measuring port tunings vs. calculated length is that once the port is over ~6" wide you don't continue to get much over that 3" of added length benefit in most cases. In other words - a port 15" wide is not going to see 7.5" of correction factor in most cases. Current system: 1997 Blazer - (4) Customer Fi NEO subs with (8) American Bass Elite 2800.1s Previous systems: 2000 Suburban - (4) BTL 15's and (4) IA 40.1's = 157.7 dB at 37 Hz. 1992 Astro Van - (6) BTL 15's and (6) IA 40.1's = 159.7 dB at 43 Hz. Link to comment Share on other sites More sharing options...
xterraboy03 Posted January 8, 2012 Report Share Posted January 8, 2012 All I know is we took that back piece off and built a new port. Now it sounds alot better. Still need to put it on the meter! 03' NISSAN XTERRA (1) AQ3500d (1) AQ4x90 (1) Audio Control Line Driver (4) DC LVL 4 15's Cresendo Mids and Highs 100' of 0/guage Big Three Mechman 270a Charging @ 16.5v (6) XS D1400's Highest Termlab Score 149.9 at the kick & 166.1 in the Port/ on stock electrical and 1 DC XL M1 Updated JUNE 2012*****MY BUILD LOG USACI REGION 6 POINTS LEADER 2011 USACI KANSAS RECORD HOLDER 2011 Team DC http://www.dcsoundlab.com/ Link to comment Share on other sites More sharing options...
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