Sealed or Ported for Spl
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=40006
Printed Date: June 07, 2024 at 7:37 PM
Topic: Sealed or Ported for Spl
Posted By: Sancho
Subject: Sealed or Ported for Spl
Date Posted: September 29, 2004 at 5:49 PM
Hi, everyone I got jbl 1200.1 amp, and 2 kicker solo baric 15L7...my question what is better for this setup sealed boxes or ported ...that's for spl
Replies:
Posted By: Rushman
Date Posted: September 29, 2004 at 6:12 PM
sealed box's usually give out the better SPLs. the tighter air space behind the woofer creates greater cone excursion making your SPL better.
Posted By: kfr01
Date Posted: September 29, 2004 at 6:21 PM
I think that's wrong. Within the operating range of a ported system the woofer should be louder with less power. Said another way, you will need more power to drive the same woofer in a sealed box to the same loudness. see https://www.diysubwoofers.org/ ------------- New Project: 2003 Pathfinder
Posted By: Rushman
Date Posted: September 29, 2004 at 6:31 PM
your probly right kfr. I come from old school of logic where the only ported boxes were the old Kicker boxes made for pick ups. They were only ported due to the lack of air space to allow the speaker to have some excursion. I forget about the advances today with Bandpass and Triband box's using standing waves to naturaly amplify the sound. I thing it just depends on what range he's trying to get the SPLs from.
Posted By: kfr01
Date Posted: September 29, 2004 at 6:43 PM
Huh .. guess that is before my time. Ported boxes usually require more, not less, air volume than a sealed box for the same driver.
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New Project: 2003 Pathfinder
Posted By: forbidden
Date Posted: September 29, 2004 at 7:06 PM
These subs and a ported encosure = SPL on a great scale.
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Top Secret, I can tell you but then my wife will kill me.
Posted By: Velocity Motors
Date Posted: September 29, 2004 at 7:38 PM
Ported enclosures gives you an extra 3 db more SPL over a sealed enclosure.
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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: boxmaker85
Date Posted: September 29, 2004 at 7:44 PM
Correct me if I'm wrong but physics tought me that 3 db is not that much of an audible difference. Normally the average person can detect around a 5, maybe 4, db difference. Like I said correct me if I'm wrong so I can get my story streight.
Posted By: Rushman
Date Posted: September 29, 2004 at 7:55 PM
actually boxmaker , you ARE wrong. The db scale is really wierd but 3 or 4 db is enough to almost double the amout of volume you hear. I think it only takes like 6 db to double the sound you actually hear. Theres a difference in db you here and electronic or digital db but both are close in scale. The numbers may not be EXACT but I know Im very close.
Posted By: Velocity Motors
Date Posted: September 29, 2004 at 7:58 PM
Your right but also remember that if your competing a 3 db gap is the difference between 1st and 2nd place. Also, it's not your ears that will be deciding what's audible or not, the SPL will be measured by the RTA and the 3 db will benefit you most in the upper parts of your SPL not in the lower parts. For every 3 db gain in SPL you have to double your power output, so if you can cheat and get an extra 3 db with just an enclosure design change as opposed to doubling your power output, then do the enclosure. ------------- Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: Ravendarat
Date Posted: September 29, 2004 at 10:42 PM
sh*t dude I have seen 3 db seperate 1st and 7 place in some comps. Esspecially when you get into the upper end. Once you get past, I think i was told, 138.7 db, then every 3 decibels gives sounds twice as loud as before.
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double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer
Posted By: boxmaker85
Date Posted: September 29, 2004 at 10:50 PM
I'm talkin about an average person with an average ear. Not the $5000 db machine that detects .0000000000001 db differences. I know that you have to double the power to get that extra 3 db but I think the guy askin the question is probably not going for the world title for spl, so his gain of 3 db at let's say 120 db is not goin to be a HUGE, noticable difference right? I would do it, but if you're going to notice a major difference is what I'm questioning. Maybe, maybe not. I'll have to take it to the sound lab that we have here at the college. See what a port does compared to a sealed.
Posted By: leroy185
Date Posted: September 30, 2004 at 12:12 AM
"I know that you have to double the power to get that extra 3 db but I think the guy askin the question is probably not going for the world title for spl, so his gain of 3 db at let's say 120 db is not goin to be a HUGE, noticable difference right? " man if you're only hitting 120 you need to get something checked 'cause i've seen 125 from a factory system
Posted By: pimpincavy
Date Posted: September 30, 2004 at 12:06 PM
Doesnt adding a second sub also add 3Db? So does that mean that having one sub and a ported box would sound like 2 subs in a sealed box? -------------
Posted By: forbidden
Date Posted: September 30, 2004 at 1:10 PM
Yes it does for the first part and no for the second part. The porting of a box will change the tuning frequency, thus the range of frequencies played and heard will be different. ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: audiobass10
Date Posted: November 01, 2004 at 9:30 PM
15L7=Ported, Ported, Ported..did i mention ported?
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Dave
Pioneer Premier DEH-P660
15" Kicker CVR
Profile AP1000M
It's Loud
Posted By: jeffchilcott
Date Posted: November 01, 2004 at 10:17 PM
yep ported massive box, thats about all i have to say about thaty along with alot of power
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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: Poormanq45
Date Posted: November 01, 2004 at 10:50 PM
Actually: . If the cone area is doubled and the cone excursion remains the same, the acoustical power increases by a factor of four:
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Posted By: Poormanq45
Date Posted: November 01, 2004 at 10:59 PM
"actually boxmaker , you ARE wrong. The db scale is really wierd but 3 or 4 db is enough to almost double the amout of volume you hear. I think it only takes like 6 db to double the sound you actually hear. Theres a difference in db you here and electronic or digital db but both are close in scale. The numbers may not be EXACT but I know Im very close."
I'm going to have to say, no, ayou ARE WRONG.
"Note the following characteristics of the decibel scale:
* It is a relative scale, ie, it is based on a ratio that compares sound intensity or pressure to a standard reference level. The reference level used is the lowest sound pressure commonly detected by man and is equal to 2 X 10-5 N/m2. Thus, the intensity level in decibel sound pressure level (SPL) = 20 log10 sound pressure/2 X 10-5 N/m2.
* It is logarithmic, not a linear scale. Doubling sound pressure results in a 6-dB increase in measured sound pressure, while a 10-fold change in sound pressure is reflected by a 20-dB change in measured sound pressure.
* The log of 1 is 0. Thus, 0 dB SPL does not correspond to the absence of sound but rather indicates that the sound pressure of the measured wave is equal to the reference sound pressure."
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Posted By: boxmaker85
Date Posted: November 01, 2004 at 11:50 PM
I've heard 140 db and then 150 db. In an enclosed area where other sound is negligable. The difference was very small, I would not have noticed if I had just been listening to it like the radio. If you can notice a change in 3 db (with your ear not a machine) then you're.... superman or something.
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Posted By: stevdart
Date Posted: November 02, 2004 at 5:04 AM
boxmaker, you're not wrong. Let the poorman spout off his textbook examples while the teacher's not looking........ When you get to a point in decibel levels, the human brain goes into protection mode. Whether a volume measures twice as loud or not, it is the perception of the human that is the important thing here. If your brain and ear canals are shut down, you've reached the limits. poorman.......does your book have anything about tact that you can read up on? ------------- 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: boxmaker85
Date Posted: November 02, 2004 at 9:03 AM
Thank you. I'm talking about a HUMAN EAR not a machine that can hear a pin drop on a pillow. Go take some physics classes. Promise I atleast know what I'm partially talking about. I've taken to many physics classes/labs to know that a person can't tell a difference (or a very very small one if they are good) between 150 and 153 db. Like stevdart said especially at high volumes you have an even more difficult time trying to tell the difference b/c your ears just not trying to bust.
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Posted By: Rushman
Date Posted: November 02, 2004 at 12:16 PM
When my girlfriend was yellin at me , It was at about what seemed like 150 db. Now were seperated and still when she yells at me its gone up to 153 db. Trust me I can tell a difference. Im just joking with you guys. TRrying to lighten the mood back down to 90 db.
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99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components
Posted By: boxmaker85
Date Posted: November 02, 2004 at 9:11 PM
No hatin' just some educatin'!! (haha that rimes....no? ok nevermind).
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Posted By: Chad7n7
Date Posted: November 02, 2004 at 9:35 PM
Just want to let you know, you gave me a much overdue laugh Rushman!! Thanks
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Posted By: Rushman
Date Posted: November 02, 2004 at 11:21 PM
I found the 12v about 2 months ago and really enjoy learning from some of the experts here and Im happy to help a few people myself but I have to inject a little humor when I can. Some of the people here (not all ) get easily offended when you insult thier intelligents. Im just breaking up the stiffness.....ha-ha no punn intended
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99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components
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