mnrookie Posted December 1, 2013 Report Share Posted December 1, 2013 I just built my brother a box couple months ago for 2 12" sdc2.5's. Haven't metered it but sounds awesome. Quote Link to comment Share on other sites More sharing options...
CJ18 Posted December 1, 2013 Report Share Posted December 1, 2013 I know nothing.................. Quote Link to comment Share on other sites More sharing options...
hdorre Posted December 1, 2013 Author Report Share Posted December 1, 2013 I understand that most of those who posted calculate optimal port area by using a formula. My question though is how many actually use that recommendation? The reason I ask is because that seems like a ton of port area. Quote On 5/8/2011 at 7:38 PM, Kranny said: On 5/8/2011 at 7:35 PM, 'Maxim' said: It hurts me inside when I read stuff like this and remember you're 15 LMFAO so true Mitsubishi 3000GT (Old Build) Headunit: Pioneer 80PRS Frontstage: (2) McLaren Audio MLT-2 Tweeters & (4) PRV Audio MR Series Neo 6.5" Mids Substage: 4 15" Hybrid Subs - Tantric Motors & Sundown Softies Amps: Banda 2.4D Amp (Tweets), American Bass VFL 350.4 (Mids), and (2) Ampere 3800s Electrical :Singer 260A Alt & JY Power Lithium 2005 Chevy Colorado Ext Cab Headunit: Pioneer 80PRS Frontstage: 4 PRV 700Ti Tweets & 6 10" Delta Mids on 3000wrms Substage: 6 Fi BTL 18s in a 4th Order Walkthrough on 3 Wolfram 4500s Electrical: Singer "390" and JY Power My Official Feedback Thread Link to comment Share on other sites More sharing options...
CJ18 Posted December 1, 2013 Report Share Posted December 1, 2013 More so, how many have used that calculation with the subs in question? I know nothing about DC subs though. Quote Link to comment Share on other sites More sharing options...
Krakin Posted December 1, 2013 Report Share Posted December 1, 2013 (edited) The boxes that I have seen JoeX post use the same formula's. Bkolfo4 builds his enclosures with it CleanSierra has built many boxes which I assume they all use the recommended minimal vent area. But do remember that these suggestions are not golden, Small stated in his second paper that the formula is only accurate up to +10%, and must use a reasonable radius for flaring. He later states that an acceptable limit is to design to 5% the velocity of sound. I however can only reference work done and documented, as I haven't been able to find the time to test it all myself. Edited December 1, 2013 by Krakin Quote 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 December 1, 2013 Report Share Posted December 1, 2013 Having less than recommended port area still works, you just have to look at each setup and determine what you are trying to do and what sacrifices you are willing to make. Couple of examples: David Moore was doing 154+ on 2 RE MT 15's with a total of 48 sqin of aero port. In the great 12" challenge years ago, they did 150 with a single BTL 12" on 5000 watts with a single 4" aero. Quote 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...
CleanSierra Posted December 1, 2013 Report Share Posted December 1, 2013 I've built several using the port area formula that I suggest and I have yet to make a peaky enclosure. I realize CJ has specific knowledge of real world experience with the subs in question. I've heard the Level 4s on a DC 3.5K I'm the same vehicle with two very different enclosures. They were in a forum member's vehicle with equipment that Cody sold him. The first enclosure had like 36" of port and got loud at tuning but fell on its face above and below tuning. The second enclosure has around 80-90" of port and it's way more musical and not nearly as peaky. The rolloff is much less noticeable and it's got more range for sure. The system sounds better with the larger port area. Granted, the first enclosure was UNDER what Cody suggests, so maybe it's not a fair comparison. I have yet to have port noise in an installation and I have yet to make box that doesn't have good musical range. I know Brian, Bkolfo, HATES the port area per foot recommendations because a sub needs X amount of port regardless of what airspace it's in. Xmax, tuning and cone area are supposed to drive the port area for a drive to operate efficiently, according to Small and all collected in the Loudspeaker Cookbook by Vance Dickason. I know there is a difference between theory and application though and I've built enclosures with less that the "mimimum" recommended. I've still tried to stay close since I believe in the formula. Quote 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...
DylanBunch Posted December 1, 2013 Report Share Posted December 1, 2013 Just making it clear, I was just makin a funny not trying to start a port area war haha Quote 2006 Ford Explorer 2 Team AA/Sundown 15s 6th order Ct Sounds 7k 4 PRV Mr500 8s Rockford p1000-2 Team Subsonic Lows Link to comment Share on other sites More sharing options...
CleanSierra Posted December 1, 2013 Report Share Posted December 1, 2013 Just making it clear, I was just makin a funny not trying to start a port area war haha I knew you weren't starting a war We are all good bro. I was just stating my approach to enclosure design in regards to port area. I think Xmax is an important factor in port area design. The part where it gets tricky is I'm not sure how accurate some of the company's Xmax figures are. Not DC specifically, but some I've seen that make me wonder. Quote 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...
Omega5002 Posted December 1, 2013 Report Share Posted December 1, 2013 I would also agree a single flared 8' port would be perfect of the pair of DC Lv 4 10's since the port velocity is there as well. Quote 2003 Kia Sorento Team Subsonic LowsTeam Bassin' on a Budget2016 Rebuild Under Construction Best score: 150.2 at 40hz (3k, 2 Custom HDC3 15's) Usaci style(door open, in the kick) Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.