SVB847 Posted August 5, 2011 Report Share Posted August 5, 2011 I was wondering if I can get the advice of some more experienced box builders on my current setup. I am running 4 - 18" Sundown Zv2 subs, each powered by a RF T15001bdcp amp. The box/wall is 39H x 49W x 28.5D.. Port is 30H x 10W x 17.5D.. With the baffle/woofer/bracing removed I am coming out to about 21.3 cubes and tuned to about 34hz according to the box calculator. The subs/box sound good, but at times the subs just sound as if they are working too hard on the low notes (sorry I dont know any other way to describe it, almost sounds like they are free air). I have set the gains w/ an O-scope, so I am fairly sure I am not clipping. I was wondering if perhaps my box/port are just too big and maybe I should make both a little smaller. Any input would be greatly appreciated. You can also see my build log in my sig to see the setup if that helps at all. Quote 2000 Chevy SuburbanPioneer AVHP8400BH8 - 18" Fi SP4 Subwoofers (fully loaded) B Pillar 4th Order (75 cubes)2 - Ampere Audio 8.0 TFE AmpsRF T6004 AmpRF T4002 Amp4 - Selenium 8W4P Mids8 - Selenium 6W4P Mids6 - Crescendo XST2 Supertweeters2 - Selenium ST200 SupertweetersDC Power 320 Alt & Js Ultimate 27011 - Group 31 BatsBuild Log:http://www.stevemead...01bdcp-updated/Team GG Link to comment Share on other sites More sharing options...
big dee Posted August 5, 2011 Report Share Posted August 5, 2011 Probly unloading Quote Link to comment Share on other sites More sharing options...
SVB847 Posted August 5, 2011 Author Report Share Posted August 5, 2011 So do you suggest taking the box down to about 19 cubes and maybe slightly less port to maintain my tuning? Quote 2000 Chevy SuburbanPioneer AVHP8400BH8 - 18" Fi SP4 Subwoofers (fully loaded) B Pillar 4th Order (75 cubes)2 - Ampere Audio 8.0 TFE AmpsRF T6004 AmpRF T4002 Amp4 - Selenium 8W4P Mids8 - Selenium 6W4P Mids6 - Crescendo XST2 Supertweeters2 - Selenium ST200 SupertweetersDC Power 320 Alt & Js Ultimate 27011 - Group 31 BatsBuild Log:http://www.stevemead...01bdcp-updated/Team GG Link to comment Share on other sites More sharing options...
Autruche Posted August 5, 2011 Report Share Posted August 5, 2011 when you say low notes, at around what frequency does it seem to do this? Quote Need Test Tones/Sine Waves? Click Here!My Saab 9000 build1993 Saab 9000 Aero 5spdPioneer - Zapco - Hifonics - Sundown Audio - O2 Audio - RE AudioJust Say No To Rear SpeakersJust Say No To CCA WireReal Men Drive StickHit me up on Facebook, if you want Link to comment Share on other sites More sharing options...
SVB847 Posted August 5, 2011 Author Report Share Posted August 5, 2011 I would say around 32hz Quote 2000 Chevy SuburbanPioneer AVHP8400BH8 - 18" Fi SP4 Subwoofers (fully loaded) B Pillar 4th Order (75 cubes)2 - Ampere Audio 8.0 TFE AmpsRF T6004 AmpRF T4002 Amp4 - Selenium 8W4P Mids8 - Selenium 6W4P Mids6 - Crescendo XST2 Supertweeters2 - Selenium ST200 SupertweetersDC Power 320 Alt & Js Ultimate 27011 - Group 31 BatsBuild Log:http://www.stevemead...01bdcp-updated/Team GG Link to comment Share on other sites More sharing options...
zx10intn Posted August 5, 2011 Report Share Posted August 5, 2011 with the way the box is put together, i wouldnt imagine they are unloading but its always possible. to me it sounds like the box may be a bit on the big side for the power they are getting, or could simply be(though not likely by looking at the build log), that the box is not as air tight as should be. Quote 1969 Chevy Chevelle 20/22" staggered Bonspeed Huntingtons wrapped in Nitto INVO's Mechman 250amp cs144 alt w/AVBM Kinetik 1800 main battery/Kinetik 2400 in the trunk Pioneer AVH-3200dvd Headunit (2) sets of Hybrid Audio Technologies Imagine components up front (2) DD 3512's d4 coils Sundown sax100.4 component amp Sundown saz-3000d subwoofer amp 5ft^3 box tuned to 34hz MY BUILD Link to comment Share on other sites More sharing options...
SVB847 Posted August 5, 2011 Author Report Share Posted August 5, 2011 Thanks for the input. I would say for the first week that may have been MOST of it, but we took literally 2 weeks of sealing/bracing/foaming/rodding everything to get it as tight as can be. It looks like I can take the box down to about 19 cubes and just shrink the port by 1/2 inch on each side to keep my tuning the same. Quote 2000 Chevy SuburbanPioneer AVHP8400BH8 - 18" Fi SP4 Subwoofers (fully loaded) B Pillar 4th Order (75 cubes)2 - Ampere Audio 8.0 TFE AmpsRF T6004 AmpRF T4002 Amp4 - Selenium 8W4P Mids8 - Selenium 6W4P Mids6 - Crescendo XST2 Supertweeters2 - Selenium ST200 SupertweetersDC Power 320 Alt & Js Ultimate 27011 - Group 31 BatsBuild Log:http://www.stevemead...01bdcp-updated/Team GG Link to comment Share on other sites More sharing options...
zx10intn Posted August 5, 2011 Report Share Posted August 5, 2011 Thanks for the input. I would say for the first week that may have been MOST of it, but we took literally 2 weeks of sealing/bracing/foaming/rodding everything to get it as tight as can be. It looks like I can take the box down to about 19 cubes and just shrink the port by 1/2 inch on each side to keep my tuning the same. cool. just test it out and see what you get... make the changes reversable so if it doesnt work out you can take them out and tweak it until you get it where you want it. Quote 1969 Chevy Chevelle 20/22" staggered Bonspeed Huntingtons wrapped in Nitto INVO's Mechman 250amp cs144 alt w/AVBM Kinetik 1800 main battery/Kinetik 2400 in the trunk Pioneer AVH-3200dvd Headunit (2) sets of Hybrid Audio Technologies Imagine components up front (2) DD 3512's d4 coils Sundown sax100.4 component amp Sundown saz-3000d subwoofer amp 5ft^3 box tuned to 34hz MY BUILD Link to comment Share on other sites More sharing options...
SVB847 Posted August 5, 2011 Author Report Share Posted August 5, 2011 For sure! Thanks! Maybe at the end of the day they just are getting enough power.. Quote 2000 Chevy SuburbanPioneer AVHP8400BH8 - 18" Fi SP4 Subwoofers (fully loaded) B Pillar 4th Order (75 cubes)2 - Ampere Audio 8.0 TFE AmpsRF T6004 AmpRF T4002 Amp4 - Selenium 8W4P Mids8 - Selenium 6W4P Mids6 - Crescendo XST2 Supertweeters2 - Selenium ST200 SupertweetersDC Power 320 Alt & Js Ultimate 27011 - Group 31 BatsBuild Log:http://www.stevemead...01bdcp-updated/Team GG Link to comment Share on other sites More sharing options...
Tarball Posted August 5, 2011 Report Share Posted August 5, 2011 I was wondering if I can get the advice of some more experienced box builders on my current setup. I am running 4 - 18" Sundown Zv2 subs, each powered by a RF T15001bdcp amp. The box/wall is 39H x 49W x 28.5D.. Port is 30H x 10W x 17.5D.. With the baffle/woofer/bracing removed I am coming out to about 21.3 cubes and tuned to about 34hz according to the box calculator. The subs/box sound good, but at times the subs just sound as if they are working too hard on the low notes (sorry I dont know any other way to describe it, almost sounds like they are free air). I have set the gains w/ an O-scope, so I am fairly sure I am not clipping. I was wondering if perhaps my box/port are just too big and maybe I should make both a little smaller. Any input would be greatly appreciated. You can also see my build log in my sig to see the setup if that helps at all. What do you have your Subsonic (infrasonic) filter set to ? Quote CURRENT SYSTEM: Alternator: Stock alt on mids/highs Isolated DC Power 270 SP - Charging @ 16.8v Batteries: (2) XS D1400s Power Cable: Double Runs of 1/0 KNU Kolossus Fleks Headunit: 80-PRS Sub Amp: DC 5.0k Subwoofers: 2 RE MT 15s /PSI dual .7ohm recones Subwoofer Enclosure: 9.1cubes @ 32hz - brutal. Mids & Highs Amp: CT125.4 Active Components: Mids RE XXX 6.5c Highs - 3 RE XXX tweeters per side(A pillar) Noise Control: Damplifier Pro all over the cab. Build Log If you do business with me please leave feedback here: FEEDBACK THREAD Highest Legal Score: 151.0 db Highest Musical 30 Second Average: 151.6 db Link to comment Share on other sites More sharing options...
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