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Old 10-31-2010, 05:15 AM   #1
dontlookback
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Default Sealed box Vs Ported box

a sealed can bang more and be closer to a wall then a ported cus u cant block a port with a wall it just wont be loud. the subwoofer and the port works different when close to a wall. a ported box will not be louder than a sealed when u place the sealed box 3 inches from a wall. sealed boxes will get loud. u can have a resonance at 38 hertz but the sealed box will be louder with the perfect wall and it wont even have a resonance at 38 hertz. many sealed boxes will have resonance at 45 hertz or 42 for about 1.2 CF. We not talkin about test tones because they are a different story but when u put a song on a sealed box might bang more. The wall does the work while u have a ported box port do the work. the walls only help a little bit with a ported box but u can put a sealed box on the wall and nothing is blocked. all u hear it bass. reflections and more sound is heard. You can make a sealed box hit the frequencies of a ported u dont have to tune it or nuthin. EQ does the job. if u know how to eq the right way. it takes certain frequencies to raise up and which ones to lower. and all you need is a truck. a sealed box in free air will defenitly be loud. and how can a sealed box be louder? you dont even need a meter you can see where ur bass goes outside the vehicle as bass travels. you dont need 20 hz in a truck from a sealed box to triple or quadriple sound. u can even have ur cutt off at 36 hertz so u wont play nuthing under it. at 39 hertz a sealed box is very loud with a wall. ported is just loud like they say with an open space. sealed gets there noise especially in a car. when u have a port where do u face they port? and a sealed sub cant be treated the
same as a port with bass coming out of it. theres differences man

Sealed boxes can take power right? i dont wana sound so convincing but at low frequencies they can take
power and ported boxes even distort quicker than a sealed box. i know they make nice ported boxes but
talk about ur average ported box in the street . ones u hear. many people dont even build there own so how
can they be so perfect?

main thing: the way bass travels in a sealed box and a ported box is different. the way bass travels has a
effect on noise, dont think a ported box just makes a lot of noise but which box is more noticable in a vehicle?

they always said a perfect bass wave a wave formed by the wall and that is a sealed box very close to a wall. the more perfect a bass wave is the more creation and completion the wave will have. a sealed box will have that advantage way over a ported box. is a wave from a ported box formed the same way as sealed box in the same vehicle?
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Old 12-06-2010, 12:32 PM   #2
up4kmann
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I'm taking first variant


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Old 06-28-2011, 03:52 PM   #3
Mobile Enclosures
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Quote:
Originally Posted by dontlookback View Post
a sealed can bang more and be closer to a wall then a ported cus u cant block a port with a wall it just wont be loud. the subwoofer and the port works different when close to a wall. a ported box will not be louder than a sealed when u place the sealed box 3 inches from a wall. sealed boxes will get loud. u can have a resonance at 38 hertz but the sealed box will be louder with the perfect wall and it wont even have a resonance at 38 hertz. many sealed boxes will have resonance at 45 hertz or 42 for about 1.2 CF. We not talkin about test tones because they are a different story but when u put a song on a sealed box might bang more. The wall does the work while u have a ported box port do the work. the walls only help a little bit with a ported box but u can put a sealed box on the wall and nothing is blocked. all u hear it bass. reflections and more sound is heard. You can make a sealed box hit the frequencies of a ported u dont have to tune it or nuthin. EQ does the job. if u know how to eq the right way. it takes certain frequencies to raise up and which ones to lower. and all you need is a truck. a sealed box in free air will defenitly be loud. and how can a sealed box be louder? you dont even need a meter you can see where ur bass goes outside the vehicle as bass travels. you dont need 20 hz in a truck from a sealed box to triple or quadriple sound. u can even have ur cutt off at 36 hertz so u wont play nuthing under it. at 39 hertz a sealed box is very loud with a wall. ported is just loud like they say with an open space. sealed gets there noise especially in a car. when u have a port where do u face they port? and a sealed sub cant be treated the
same as a port with bass coming out of it.
theres differences man

Sealed boxes can take power right? i dont wana sound so convincing but at low frequencies they can take
power and ported boxes even distort quicker than a sealed box. i know they make nice ported boxes but
talk about ur average ported box in the street . ones u hear. many people dont even build there own so how
can they be so perfect?

main thing: the way bass travels in a sealed box and a ported box is different. the way bass travels has a
effect on noise, dont think a ported box just makes a lot of noise but which box is more noticable in a vehicle?

they always said a perfect bass wave a wave formed by the wall and that is a sealed box very close to a wall. the more perfect a bass wave is the more creation and completion the wave will have. a sealed box will have that advantage way over a ported box. is a wave from a ported box formed the same way as sealed box in the same vehicle?
As an acoustical engineer, I have to say that all of these statements in bold are incorrect. If you would like me to shed some light on the subject of wave propagation and different enclosure designs advantages and disadvantages (real world and calculated), please let me do so. This post needs much help with all do respect, but I do understand where your trying to come from. Im not hating on what you said at all, Just want you to understand more accurately what you said and correct the misconceptions.
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Old 06-28-2011, 03:55 PM   #4
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Later, I will be explaining the correct statements of the bold ones for everyone on here. This will take some time to write, so bear with me...more to come later....as of right now...gotta celebrate my b-day.
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Old 06-29-2011, 12:46 AM   #5
Mobile Enclosures
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Quote:
Originally Posted by Mobile Enclosures View Post
As an acoustical engineer, I have to say that all of these statements in bold are incorrect. If you would like me to shed some light on the subject of wave propagation and different enclosure designs advantages and disadvantages (real world and calculated), please let me do so. This post needs much help with all do respect, but I do understand where your trying to come from. Im not hating on what you said at all, Just want you to understand more accurately what you said and correct the misconceptions.
Quote:
Originally Posted by dontlookback View Post
a sealed can bang more and be closer to a wall then a ported cus u cant block a port with a wall it just wont be loud. the subwoofer and the port works different when close to a wall. a ported box will not be louder than a sealed when u place the sealed box 3 inches from a wall. sealed boxes will get loud. u can have a resonance at 38 hertz but the sealed box will be louder with the perfect wall and it wont even have a resonance at 38 hertz. many sealed boxes will have resonance at 45 hertz or 42 for about 1.2 CF. We not talkin about test tones because they are a different story but when u put a song on a sealed box might bang more. The wall does the work while u have a ported box port do the work. the walls only help a little bit with a ported box but u can put a sealed box on the wall and nothing is blocked. all u hear it bass. reflections and more sound is heard. You can make a sealed box hit the frequencies of a ported u dont have to tune it or nuthin. EQ does the job. if u know how to eq the right way. it takes certain frequencies to raise up and which ones to lower. and all you need is a truck. a sealed box in free air will defenitly be loud. and how can a sealed box be louder? you dont even need a meter you can see where ur bass goes outside the vehicle as bass travels. you dont need 20 hz in a truck from a sealed box to triple or quadriple sound. u can even have ur cutt off at 36 hertz so u wont play nuthing under it. at 39 hertz a sealed box is very loud with a wall. ported is just loud like they say with an open space. sealed gets there noise especially in a car. when u have a port where do u face they port? and a sealed sub cant be treated the
same as a port with bass coming out of it. theres differences man

Sealed boxes can take power right? i dont wana sound so convincing but at low frequencies they can take
power and ported boxes even distort quicker than a sealed box. i know they make nice ported boxes but
talk about ur average ported box in the street . ones u hear. many people dont even build there own so how
can they be so perfect?

main thing: the way bass travels in a sealed box and a ported box is different. the way bass travels has a
effect on noise, dont think a ported box just makes a lot of noise but which box is more noticable in a vehicle?

they always said a perfect bass wave a wave formed by the wall and that is a sealed box very close to a wall. the more perfect a bass wave is the more creation and completion the wave will have. a sealed box will have that advantage way over a ported box. is a wave from a ported box formed the same way as sealed box in the same vehicle?
Ok, for most of these, the answer mainly relies in the fact that it is based on many variables that are not mentiioned in this post and for most, it becomes relative to the equipment and listening preference and design goal. But for sake of arguement, let's say we are talking about both design types being identical: same enclosure persay, same applied voltage and amplifier and same driver and even vehicle. So, the first statement says a sealed can "bang" (which it seems this term is the expression of percieved loudness to this person), more than a ported and be closer to a wall cuz u can't block a port with a wall, it won't be loud.....to this I say first...the "bang" relies on much more than the location of the design but as a stand alone variable, placing the port near a wall has other effects on the propagation of the sound than loudness. I do agree that blocking a port is obviously a no no, as this would limit the output and likely affect the calculated response a little, but as far as output in sound pressure terms, it will not affect the "loudness" if close to the wall without touching the wall, as the only physical change that will take place would be the compression ratio of the sound waves, which in turn will likely increase sound pressure if anything....to a point of normalized distance that is, where the port can be close to the wall and again not "fully blocked" or closed up.

Now I have read this over agin and comprehended the terms used as some of them are just not put the right way, but do make some sense, so my bold statements might have changed a little, but not much. So, numvbr two...

Says, a port will not be louder than sealed when you place the sealed 3" from the wall. Now, again relativity takes major place in this as again many other factors are to be considereed, such as...is the ported placed the same distance, is the power the same, same song, etc. These need to be considered when making a relative statement such as this. So, this is incorrect in that it was not thought through as to what other factors alow or do not allow it to be true...which again have to be evaluated first. Its possible a sealed can be louder in that sense as it is correct that it will cause pressure gain, but for any design type this is existant as the gain from the environment is based on room mode and transfer function as a concrete response without the added enclosure response. So this mentioned gain will have the same effect on the response of any design. But if the gain has a harmonic resonance identical to the sealed design and the ported design was not designed for a resonance at that frequency or others, then yes, this statement may become true for obviouse reasons.

Number 3, states u can have a resonance at 38hz but a sealed will be louder and not have a resonance at 38hz....this like all others will rely on variables. Now, in general, under the same operating conditions, the mentioned resonance will exist for both design types if they are calculated to have that resonant frequency. What it sound like her is that this person is saying because it is sealed, it will not have a resonance at all. This is not true. The parameters and propagation of the driver and environment are existant to the point in any enclosure design where resonances occur. Its just that in a sealed design, those resonances are containedand compressed more so than a ported design which utilizes it for further extended output. But a sealed enclosure will not always be louder nor quieter as this is a change that exists independantly for any design goal and type.

Number 4..states many sealed enclosures will have a resonance @45hz and 42hz for 1.2 cubic ft... now, I'm not sure why this matters in this paragraph along with the fact that it is not always true, to a point that each drivers mechanical parameters will show different resonances added to the environmental resonances in any sealed enclosure of equal volume. Each driver will have its own unique respoonse regardless of the enclosure size and shape and layout....again....to a point. So, in this statement, it becomes partially true in that drivers of similar parameters will show near identical resonances, but this is not true for an absolute statement to be used with exact numbers.

Number 5 and more will continue on the next post.....
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Old 06-29-2011, 01:09 AM   #6
Mobile Enclosures
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Continued....
Number 5...states when you put a song on, a sealed might bang more....ok, in and to what extent does this make sense? There are too many factors in a design for this to be true always. So this one is simple.......cancel that out. With respect to having again, the same setups, this will be true if applied power can be exceeded in a sealed enclosure, but this would likely only be true if the ported design was improperly constructed and designed

Number 6....in a sealed, the wall does the work and in ported the port does the work...now I hope I'm understanding that when you mean work, your talking about gain rather than full caccountable response. Because if you are reffering the full response, this is absolutely incorrect...as a matter of fact, it may be incorrect anyway, as the acoustical gain of a wall or interfering structure where resonances occur for added gain are existant, any design will rely partially on that gain as a total output response due to the fact that sound propagation is still existant regardless. So, this is true to a point again, but shall be corrected in a sense that the wall wil add gain to any design identically when the design will have the same response curve. So, knowing that it is likely that it will not be the same response curve for a sealed vs ported in real world testing, this gain can give different results as a final response curve ONLY if the original response is different. Once the sound exits the environment of the enclosure, minimal changes to the response are added as a result of enclosure response and then become environmental, in which that gain is considered a constant based on time vs frequency.

Number 7...states walls only help a little in ported, but you can put sealed on the wall and nothing is blocked...reflections and more sound is heard.....
So, this actually does make sense to me..but again we are referring to a ported design that may have the port fully sealed by the wall structure, which in turn would create the sealed enclosure environment..so the only difference then would be that the inner ports of the ported design causes a different response within the design and cubic volume is affected as resonances are different as well, even though hypothetically it has became a sealed design by blocking the port. This affect is why it may be assumed that a sealed design will have more gain or as mentioned, sound...because of different physical structures are now being compared. Where one of them is purposly restricted. Now, if the ported design lies the same distance from the wall as the sealed or even if the sealed is against the wall structure, a large difference in distance would need to be existant for the ported design to suffer from loss of output as the wall will aid in its output as well. Enough said about that.

Number 8...states you can make a sealed hit frequencies like the ported but don't have to tune it or nuthin....
Ok, this is agin not correct because even thought the design is sealed, does not mean that proper acoustical compression shall not be accounted for to gain a proper response or operation of the driver installed. Doing nuthin will likely get you to have to purchase more drivers from eithe mechanical or thermal limitations being exceeded for a long enough period of time to cause permanent damage. This would be from improper cubic volume and trying to accomplish the same output pressue and intensity of the response passband. Making it too small would likely result in thermal limitations being exceeded and vise versa for a larger enclosure where mechanical limitations are more likely exceeded.


More to come on number 9 and more in the next post......
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