ported or sealed?
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=41951
Printed Date: May 19, 2024 at 10:31 PM
Topic: ported or sealed?
Posted By: 1badnotch
Subject: ported or sealed?
Date Posted: October 30, 2004 at 9:19 PM
i have one audiobahn aw1051se to put in my 2000 sonoma reg. cab what would be the best choice for the best bass i was thinking a medium sized sealed box
Replies:
Posted By: Poormanq45
Date Posted: October 30, 2004 at 9:27 PM
I would suggest a sealed enclosure with a passive radiator of the same size as your sub. The radiator with have a resonating frequency approximately 1 octave lower than that of the sub. This is all assuming you tune it correctly.
Anyway,IMO, a sealed enclosure with a passive radiator gives you a very good conbinatation of SQ and SPL.
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Posted By: 1badnotch
Date Posted: October 30, 2004 at 9:32 PM
where would i get a passive radiator ive seen them but would my car audio shop have these? would it go on the back of the box? space is limited
Posted By: Poormanq45
Date Posted: October 30, 2004 at 9:43 PM
It can go on any side of the box that you chose. As the air is sealed inside of the box. So, it's going to expand whereever it can(the passive radiator).
I don't think your local car audio shop would have radiators. For some reason, not many people use passive radiators in cars anymore. Makes no sense to me.
You can find radiators online. Search google for "Passive-radiators" or "speaker rings".
I'll look around for some websites and then post them here.
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Posted By: Poormanq45
Date Posted: October 30, 2004 at 10:17 PM
Posted By: stevdart
Date Posted: October 30, 2004 at 10:36 PM
1badnotch wrote:
i have one audiobahn aw1051se
Post a link showing the T/S parameters of this sub. And also, do you have a spec sheet with it, and does the manufacturer recommend any type of enclosure? ------------- 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: DYohn
Date Posted: October 31, 2004 at 9:25 AM
Clarification: A passive radiator speaker system is not sealed, it is vented. Using a PR can be very tricky as they tend to have very high distortion around the PR resonant frequency, they can create severe phase cancellation problems and thus can make speaker placement very, very critical. A PR subwoofer can create much more deep bass response than a typical acoustic suspension design with the same driver, but only around the PR resonance. IMO they are much more difficult to build, to use properly and especially to create acceptable sound quality than almost any other speaker design and should not be attempted by a beginner. https://www.diysubwoofers.org/prd/------------- Support the12volt.com
Posted By: Poormanq45
Date Posted: October 31, 2004 at 4:19 PM
Ya, your correct about it being hard to build and Properly tune them. That is probably why not many people use them in car audio systems.
The distortion that you mentioned usually comes from the PR over-extending or bottoming out. You can prevent this from happening by using a PR that is larger than the actual driver.
I PR system is technically in the class of Bass-reflex (Ported) class, but just think about the way they work. The air inside of them is traped, air neither escapes nor enters the enclosure. The PR supposedly acts as a port by "containing" a constant volume of air.
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Posted By: haemphyst
Date Posted: October 31, 2004 at 8:10 PM
Just my little note regarding PRs... The way to tell which PR you need is to find one with a swept volume of AT LEAST TWICE the swept volume of the driver you are trying to match it to. Xmax times Sd equals swept volume. A PR enclosure behaves THE SAME as a vented enclosure, except the active driver does not unload as quickly below the tuning of the enclosure, as it does in a straight vented box. This helps protect the driver without subsonic filters and the like. The distortion can be SIGNIFICANTLY lower than the same driver in a sealed box, due to the lower excursion. They also do not suffer from port noise. They are WAY, FAR, MUCH, COMPLETELY (and a lot) harder to build correctly, but if done right, can be truly amazing. My Eclipse Titanium 10 went flat to 18Hz (anechoic) in 2.2 cubic feet. Ya shoulda heard it in my car!!! DAMN!!!
Adire Audio makes a hella impressive PR, called the PR15, and I have used it, with extreme success. (Also some fairly spectacular failures LOL). One of those successes was the above mentioned match with the Eclipse Ti. Completely tunable, it is an ideal PR for most drivers up to 12 inches, and even some 15's.
Mr. Kephart, is this item still available through Kyle? I think I still want a couple to stack under the bench... ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: 1badnotch
Date Posted: October 31, 2004 at 11:05 PM
heres the specs. fs-42.7 hz, qts-0.82hz, qes-0.96, qms-5.64, vas(liters)-20, vas(cu. ft.)-0.7,re-3.0ohms,le-1.4mh, mmd-94grams, xmax+/- 13mm, rms-300, sd-0.033m2, freq. resp.-28hz-1khz, efficiency-91 db., ebp-44 hope this helps
Posted By: stevdart
Date Posted: November 01, 2004 at 7:20 AM
Yes, sealed enclosure is the way to go with that sub. Put it in a 2 ft^3 box. You could go even larger, but I doubt you would have that much room to work with. But I wouldn't go any smaller.
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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: Jeffpaulus
Date Posted: November 01, 2004 at 12:47 PM
You also need to consider what type of sound you want from this sub. A ported box will play louder than a sealed box, with less power. A sealed box will be more accurate but require more power. The type of music you listen to is a big factor in choosing box design. Even if this sub is optimized in a sealed enclosure, you may want to choose a ported or even bandpass enclosure if you only listen to rap. Jeff ------------- Deck - Eclipse CD8443 - $475
Speakers - Boston BAZ5 - $1000
Amp - Alpine MRV-T420 - $400
Car - 1988 PLymouth Colt - $450, it's been rolled!
Posted By: boxmaker85
Date Posted: November 01, 2004 at 1:03 PM
I would only recomend bandpass for the experienced installer. And even then it's a very tricky project to do. Bandpass also play extremely loud at certain frequencies. Other notes higher or lower then the tuned one will sound quieter and not nearly as good. Ported would be a great choice if you want the "boom" of your bass music. Not an easy project but the output of them can be greater then the sealed. I would go for the sealed though. Subs sound tight and accurate in them. They are easy to build and can be versitile for many types of music.
Posted By: stevdart
Date Posted: November 01, 2004 at 8:10 PM
It's a no-brainer choice for this sub. The EBP falls squarely in the sealed catagory at 44. It would be a nightmare to try to get something half decent with ported or especially bandpass with those specs.
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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: 1badnotch
Date Posted: November 02, 2004 at 3:07 AM
great thanks everyone eric
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