Brian2435 Posted June 23, 2012 Report Share Posted June 23, 2012 So let's just say(this whole situation is hypothetical) you had two enclosures with equal volume. You also had two cylindrical ports. One with a 2 inch diameter and with a length of 8 inches, and one with a five inch diameter and a length of 15 inches. Let's just also say that both ports would have equal tuning when put in the enclosure. Would there be any sound difference in the two different ports, even though they have the same tuning with the enclosure volume? Quote Link to comment Share on other sites More sharing options...
Joe X Posted June 23, 2012 Report Share Posted June 23, 2012 All other things being equal the box with the smaller port will experience higher airspeed, if this airspeed becomes too high then an number of effects appear, first lost efficiency and then turbulence which may hurt a bit sound quality and if the airspeed is really high the port will start generating noise. If the port turns or has sharp edges in it the those effects will appear earlier, Of course if the subwoofer can't move that much air then those effects may not apperar. There are other slighter effects not mentioned. Quote Link to comment Share on other sites More sharing options...
OrionStang Posted June 23, 2012 Report Share Posted June 23, 2012 What if the port is too big, Joe X? What effects will you see then? Quote SMD Super Seller My Feedback Thread Link to comment Share on other sites More sharing options...
98GCLimited Posted June 23, 2012 Report Share Posted June 23, 2012 ^ unloading? Quote Link to comment Share on other sites More sharing options...
AMI CUSTOMS Posted June 23, 2012 Report Share Posted June 23, 2012 To the OP, considering all things equal but port area, yes it does affect output, as long as port isn't too big you will generally see increase in output and you increase port area. Quote TEAM SOUNDQUBED -- TEAM SOUTH TEAM S.O.B. - Founder & Captain 3x Streetbeat World Record Holder 2017 MWSPL 1st place Mayhem & 4th Xtreme 4 2016 MWSPL 1st place Mayhem/2nd Adv 4/2nd Xtreme 4 2015 MWSPL 2nd place Mayhem & 4th Xtreme 4 2014 USACI 2nd place Streetbeat 5 - 162.6 db 2014 MWSPL 2nd place Xtreme 4 - 144.9 db 2013 USACI 1st place Streetbeat 4 - 161.9 db 2013 USACI 1st place Street Q+ - 162.8 db 2013 MWSPL 3rd Kaos2 & 4th Xtreme 4 2011 USACI 2nd place MOD 1001-2k - 160.0 db 2011 MWSPL 4th place: Adv3 - 157.8 db, Kaos2 - 150s db, Xtreme4 - 140s db 2010 ARSPL 1st place 501-750 - 160.3 db Arkansas loudest Best score to date 164.4 db - Termlab Outlaw Streetbeat 4 - 161.9 db Streetbeat 5 - 162.6 db MWSPL on Dash Legal door open (Music) - 162.5 db Sealed on dash Legal (Music) - 161.1 db - Termlab THE BLACK NASTY CURRENT BUILD & FAB The Black Nasty (6) 15 Rebuild Log 2012 (4) 15 Walled Sierra Build Log Evo X build log Facebook page The Black Nasty Link to comment Share on other sites More sharing options...
Brian2435 Posted June 29, 2012 Author Report Share Posted June 29, 2012 Thanks for the responses. I saw online that per cubic foot of enclosure volume you should have 15 sq inches of port area. Has anyone heard of anything like this? Quote Link to comment Share on other sites More sharing options...
Joe X Posted June 29, 2012 Report Share Posted June 29, 2012 (edited) Thanks for the responses. I saw online that per cubic foot of enclosure volume you should have 15 sq inches of port area. Has anyone heard of anything like this? 12 to 16 square inches of port area PER cubic feet of net volume for slot ported boxes, High excursion subs are given more port area so lean towards 16 with those. It's just a rule of thumb that makes it easy to have a viable port without having use math/modelling oriented methods. Edited June 29, 2012 by Joe X Quote Link to comment Share on other sites More sharing options...
Crandis16 Posted June 29, 2012 Report Share Posted June 29, 2012 (edited) Thanks for the responses. I saw online that per cubic foot of enclosure volume you should have 15 sq inches of port area. Has anyone heard of anything like this? 12 to 16 square inches of port area PER cubic feet of net volume for slot ported boxes, High excursion subs are given more port area so lean towards 16 with those. It's just a rule of thumb that makes it easy to have a viable port without having use math/modelling oriented methods. would you consider a DC lvl 4 m2 12" to be a high excursion sub? if so then I need to redesign!Edit: sub hooked up to an SAZ-1500D v2 Edited June 29, 2012 by Crandis16 Quote My Red zx2 Build Log My Black zx2 Build Log My Red zx2 UBL Link to comment Share on other sites More sharing options...
Brian2435 Posted June 30, 2012 Author Report Share Posted June 30, 2012 Thanks for the responses. I saw online that per cubic foot of enclosure volume you should have 15 sq inches of port area. Has anyone heard of anything like this? 12 to 16 square inches of port area PER cubic feet of net volume for slot ported boxes, High excursion subs are given more port area so lean towards 16 with those. It's just a rule of thumb that makes it easy to have a viable port without having use math/modelling oriented methods. Sounds good man thanks Quote Link to comment Share on other sites More sharing options...
siucsaluki11 Posted June 30, 2012 Report Share Posted June 30, 2012 didn't read the thread, just woke up, and the xanax i ate at bedtime has yet to wear off (its prescribed guys) So I'm kin dad groggy... But yes, port size makes a hug he difference. In my blazer, i had a tiny port, hit a 135 on the TL. Built a new box, same amp, same internal volume, same tuning, but bigger port, score went up to 138-9. Built a new box, slightly bigger, and a bigger port still, went up to a 141.xx @37 HZ Port size DOES matter, no matter what your gf may tell you. Quote woman..cant live with em...cant shoot em...guess were all fucked You might be a Redneck if you use your leftover gutters for a speaker box port... YOU JUST LOST THE GAMER.I.P. Blazer=========================Last setup was in the 141s on music (37hz) with 2 12s and 1kw in a 4dr blazer.2010 Mitsubishi Lancer DE2 12in Clarions (kept from blazer)HiFonics BRZ1700.1d (at 2 ohms BLOWN) [JBL GTS180X for subs currently 60wRMS x2ch!!!!!! This works for till i get the blown amp fixed] Alpine 4ch salvaged from blazer (currently near death)9887 peerless 7s in the doors and CDT tweeters ran active no speakers in the rearKintik HC1400 under the hood.metered once a while ago, dont remember it...was piss poor compared to the blazer, mid 130s i think....looking to replace subs and amp when i have money. Link to comment Share on other sites More sharing options...
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