Port Design
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=40748
Printed Date: May 19, 2024 at 9:11 AM
Topic: Port Design
Posted By: fatgotti
Subject: Port Design
Date Posted: October 12, 2004 at 2:53 PM
I am building a box for two 15" DC subs ( SPLW 15's ) the spec's recommend 3.4 ft3 of space, tuned to 40 Hz and they say you need 2 ports 4" in Diameter and 10" long for each sub. I have built quite a few enclosures in my short career but this will be my first ported. The speakers can handle 1400 RMS. my ?'s are do Ireally need all that power even though they are only made for ported enclosures and does the box have to be 7ft3 for 2 and can I make the ports slotted into the box and if so how? or should I use those PNR ports or what. I am really into car audio & video but have always used sealed boxes and need as much info as anyone is willing to share with me!! ------------- Fatgotti Yeah my name is John and I am FAT!! YEAH BABY
Replies:
Posted By: fatgotti
Date Posted: October 13, 2004 at 12:52 PM
Anyone with any experience building ported boxes please help I am really wanting to start on this project but these subs were built only for ported and I am an idiot on this subject (not that I am not an idiot anyway) ------------- Fatgotti Yeah my name is John and I am FAT!! YEAH BABY
Posted By: stevdart
Date Posted: October 13, 2004 at 5:14 PM
do Ireally need all that power even though they are only made for ported enclosures Check the woofer manual to see what the range is on those woofers. Most of them can perform fine with half the RMS. If there is no information about that, contact tech support of the woofer manufacturer. I've found most of them respond quite quickly to questions like that. and does the box have to be 7ft3 for 2 3.4 ft^3 for one would make it 6.8 ft^3 for two. Any changes at all in enclosure volume would necessitate a change in the ports. For your first ported box(es), it would be best to follow manufacturer's guidelines. and can I make the ports slotted into the box and if so how? Most spec sheets for vented subs will give you the sizes of slot ports if that's what the maker intended for the subs. But I have been getting some use from the free program WinISD. If you download it, follow all the help files, and get your woofer specs entered into it, you'll find that you can switch from round ports to rectangular ports by clicking on the port type icon. The program will figure the different size for you. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: fatgotti
Date Posted: October 13, 2004 at 5:36 PM
Thanks alot, I order from Audio Enhancers and the tech guys deal with this everyday but they are not to quick to help you understand how tuning really works, they are more interested in you ordering their pre fab boxes which does not help me in this situation because they don't carry a enclosure that size. they do carry one with 5.5ft3 of space but it is one single chamber. He says that it would be fine in that box but will not tell me why or how, and I guess that should be enough for me but for this knowledge hungry DIYer I just needed to dig a little deeper.. thanks for the link I will put it to use..
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Fatgotti Yeah my name is John and I am FAT!! YEAH BABY
Posted By: stevdart
Date Posted: October 13, 2004 at 5:46 PM
You should build your own. All the info you need is readily available. Make sure you don't change the size to use a pre-made box. Most of the experts here will tell you to either build your own to specs, or hire someone to custom-build one for you...when using a ported design.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: fatgotti
Date Posted: October 13, 2004 at 6:20 PM
thanks for the info do you happen to Know where to get long ( 17" or better)ports. I can get those PNR ports but they are $11 a piece at dealer cost and I need eight of them. Or do you think the PNR ports are worth the extra $...
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Fatgotti Yeah my name is John and I am FAT!! YEAH BABY
Posted By: stevdart
Date Posted: October 13, 2004 at 7:40 PM
https://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=268-352 ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: jeffchilcott
Date Posted: October 13, 2004 at 9:33 PM
frankly i would build my own box will save alot of money for the time it will take to build what kind of subs are you running and we can help you with a box design
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: premieremind
Date Posted: October 13, 2004 at 9:33 PM
a good software like probox will help you design exactly what you need/want. It allows you to see the response of the box as you play with its demesion and port sizes. Email if you need further help.
Posted By: jeffchilcott
Date Posted: October 13, 2004 at 9:51 PM
i just noticed the subs were SPL w series subs? if this is correct then I would never go with 3.4 cu ft per sub, thats seams like a lot of orver kill for those subs, I could see that with maybe the big big SPL subs but not the W series. I wouldnt go with anything over 1.8 per sude if you want any kind of SQ what so ever, If not I really think the bass will get really boomy, and sloppy
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: fatgotti
Date Posted: October 13, 2004 at 10:06 PM
I am building a box for 2 15" SPLW 15's if you want you can check www.splusa.net but the spec's are as follows 2800 watts power handling 1400 watts RMS 340 oz magnet 4" BASV/Kapton hybrid 18 awg voice coil FS 29.1 Hz Vas 1.6cu. ft. Qes 0.52 Qms 4.06 Qts 0.31 Xmax 0.59" SPL 92 db Sealed box N/A Ported Box 3.4cu. ft. Tuning 40 Hz Port size 4" (dia) x 10" (length) # of ports 2 This is straight off the website I have hooked up quite a bit of their ML series which is a step down from these and those really have some punch to them with only 370x2 RMS do you have any recomendations on how much power you would put to them they are dual 1 ohm voice coils so I can wire the voice coils in series and the speakers in parallel to put a 1 ohm load on a class D amp. But I am sure you are alot more experienced than I and am looking for any insite on my project. thanks again for all the help.. ------------- Fatgotti Yeah my name is John and I am FAT!! YEAH BABY
Posted By: fatgotti
Date Posted: October 15, 2004 at 8:53 AM
Has anyone used or heard the SPLW series? If so give me a little input.. ------------- Fatgotti Yeah my name is John and I am FAT!! YEAH BABY
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