I know there are some out there by bazooka, but they're known for giving off less bass and are made to save room.
What if you compared a rectangular box to a tubular one with the same volume, what would the difference be?
I was thinking about this cause when I think of a sound wave, I think circles.
Anyone know why rectangular boxes are the norm?
Replies (23)
ttocs on 02/15/2004 17:36:46
it is easier to cut wood into squares, not circles.
Bazooka's are not a bad system. I had a pair back in the day and would use them again if the need arose. They tend to give off a less sound as they do not use drivers that are as good as alot of others available without a box.
cplkittle on 02/15/2004 23:42:13
Like ttocs said, it is all about the wood.
The first experiments in transmission lines were in tubes the same size as the driver. Round is actually ideal-think about it.. all musical instruments are round in shape. woodwinds, brass, strings, flutes, drums, cymbols, even chimes and 99% of all latin rhythm percussion instruments, The only thing I can think of that is not round is the xylophone, but the variations on that including the miramba and vibraphone have round resonators mounted below them.
This is a good question, and I don't know what difference it makes turning everything square, but I have seen alot of information that always points back to circles. for example, on the JL and Kicker websites, they recommend as close to square ports as possible if not round. Slotted ports do seriously dampen some frequencies-usually in octaves for example if your slot port dampens 10Hz, it will more than likely dampen all octaves above that on the same key (10, 20, 40, 80, 160, 320 etc).
SUBTROY1 on 02/16/2004 01:34:36
Here's a website that makes tube enclosures, not loaded. http://www.subtoms.com/index.html Unique. I had some Bazooka's before, they actually can put out some solid bass. I had 2 8's powered by a Punch 60, it shook my rear view and I remember it shaking a cassette tape in the front seat. They may not go as deep as some but they are pretty good nontheless and are good if you don't want to fill your trunk up with a huge box.
Troy
carbudgetaudio.com
erikcooper on 02/16/2004 23:55:15
You make could look into how much air space is in a bazooka tube as well and see if you could replace the bazooka driver with a more high quality one, you may be surprised what comes out...
kiaman on 02/17/2004 03:32:45
lol, my cdt 6.5's shake my rear view mirror....that dosnt take much to do.....but yea tubes are great enclousures......common place in high end HT systems.
kiaman on 02/17/2004 03:33:43
also...its not a box.....its an encolusure GRIN
(reffering to the title of this thread)
swez on 02/18/2004 19:36:25
Agreed, a tubular enclosure is a very good way to go for sub applications. The trick is to reinforce the tube well enough that it does not resonate at audio frequencies.
Tubes can be made of fiberglass, high impact plastics and other rigid materials. They tend to save space and if you get the throat of the tube large enough, 10's, 12's or a 15" woofer can be used. Just make sure you have the proper cf internally for a given sub .
Swez
PS The real plus side of a tube... no reflections from the back wall of the enclosure. It can also be ported if one so desires.
alanjlamore on 02/18/2004 21:05:43
I'm suprised that I've never seen any enclosures like these besides the bazooka's and now the subtoms from the website that SUBTROY1 provided (thanks by the way GRIN).
I've never been to an actual competition, so I don't know if it's more common there or not.
Does anyone know any other websites that has these?
I've searched a ton of search engines and couldn't find any.
Relax_The_Mind on 02/19/2004 04:26:15
Why not tubes? The general idea of the "round" design carrying on from the round and the general sub being round. Bass frequencies are generated from the moving of air inside the box.
The shape of the enclosure, in most cases, does not affect the
sound output of the subwoofer. The difference between box types such as multichamber enclosures, ported, and sealed are in the way they redirect the airflow coming from the sub. If you think about it, that is why subs dont do well parallel with to a wall because of the "standing waves" you get from the reflections.
Part of the sound even comes from the enclosure itself from the minor flexing of the different walls. Which is why you rarely see sealed boxes made our of iron or stainless steel and is one of the main reasons MDF is the most popular wood to use. Harder materials are generally used in the ported type enclosures.
Sound waves yes they have a cone effect when the sound emminates from the enclosure/subwoofer. A sub does NOT push air out in a perfect cone, circle, anything. Therefore coupling that with a tubular enclosure makes no real sense.
Dampening of frequencies from the ports is more related to port length rather than the shape of the port. Think of a pipe organ which uses that theory of odd and even octaves. All the pipes are generally the same size but different in length.
To answer your question...rectangular boxes are the norm because they maximize space usage in most cases whereas a tube would leave you with four unused areas if you think of them in a rectangular sense. Easier to build of course for the average box builder.
RTM
Once again did i make any sense?
swez on 02/19/2004 09:33:05
Pipe organ... same sized pipes? Come on, ever look at one up close? The sound tubes in a pipe organ are many different sizes, both length and diameter. The low end pipes are large in both diameter and in length. The high pitched pipes are short and small in diameter.
Basically, a pipe organ is like a huge grouping of flutes. Each is tuned to a specific frequency by length, diameter and amount of air space they contain. These are similar to speakers in some ways as each is precisely tuned to a given frequency. When air from the bellows is applied to a given pipe, (flute) it emits a whistle effect tone.
Think of pipes as pop bottles of differing sizes. Large bottles will produce low tones while small bottles produce high pitched tones. If you add fluids to them, it changes the pitch of the tone right?
Just bustin your chops in fun there RTM. But yeah, go to an old Church that has a big pipe organ and let someone show you how it works. Very impressive technology for such an old instrument... and the larger organs can produce notes below 28 Hz. That really shakes the pews dude!
Swez SMILE
PS If you ever go to Chicago, try to make a trip downtown to Moody Memorial Church. They have one of the most ellaborate organs in the Midwest. The guy that plays it most is named John Innus. Maybe he will give you a demonstration and some theory behind this magnificent pipe organ. You'll be amazed at the sound and skills that John has with this massive organ.
I listen to Moody radio a lot here in FL. They often have organ music as part of their praise and worship part of each program. Everytime I hear John whip up a strong wind with this machine... I get goose bumps. Awesome sounds dude!
Relax_The_Mind on 02/19/2004 17:39:53
Actually my statement was "All the pipes are generally the same size but different in length." I can explain why.
Ive studied pipe organs as well as other instruments. Older pipe organs and even the most elaborate ones depend on huge wind pumps and resivoirs (done manually with humans pulling big ropes and bellows to produce the air) for the bursts of air and the keys (stops,registers) actually release the air . The pipes yes are in different diameter but if you broke it down into an equation the actual differences in pitch and frequency. The higher the octave you want, the longer the pipe has to be. Each pipe will always only be able to play a certain tone but only at an odd or even octave depending on the length.
Taken from a Pipe Organ site.
"There are no keys or holes in the pipes of the organ to control the pitch. An organ pipe's pitch is determined by the length of the pipe."- http://nersp.nerdc.ufl.edu/~bodinew/
A pipe organ is a very good example to use for acoustics and physics (my fav subject).
If you ever get the chance to check out the many that are in the churches of new york city (you can try but a lot of the churches dont allow pictures....) I especially like the ones in St. Patricks Cathedral over 9,000 pipes... But yeh at family friends wedding up in nyc i forgot the church name...pipe organs give me chills down the spine. Really...reminds me of phantom of the opera type deal.
RTM
swez on 02/19/2004 21:00:34
Hummm, very interesting piece you linked me too. Thanks for sharing that one with me.
Yes, I have heard the St. Patrick's Cathedral organ on a radio broadcast where Paul Winter does his Winter Consort Series each year. The radio would hardly do it justice, but I could tell this was one special instrument.
Again, interesting read on Pipe Organ design and technology. Now they even use PVC resonator pipes I noted.
Swez
SUBTROY1 on 02/23/2004 02:27:54
Speaking of Phantom of the Opera, get a CD of it, some pretty impressive bass notes are in this tune. But back to the tubes, you can use SonoTube for subwoofer enclosures too. This is the tubes that are used to form concrete pillars. I think there are other brands of this type of thing you could pick up at Lowes, or Home Depot. I think the main thing is making sure that you have a solid mounting hole created, for the sub to be mounted to. I have an old set of Bazookas, now they look like they are made from PVC held together with some type of really wide tape that spans the length of the tube. The way they make them now may be different.
Troy
carbudgetaudio.com
swez on 02/23/2004 08:07:42
Yep, SonoTubes are a very good baseline material to work with prefab tubes. Comes in several diameters and you can just cut them to length you want. Probably a good idea to reinforce the outside with fiberglass to keep them strong an rigid as they are basically cardboard. Cheap too!
Swez
eldevioso on 02/28/2004 02:10:04
Here's my two cents:
I've built a few tube enclosures to date. Actually I've only built tube enclosures. I use a strong cardboard type material used as molds to pour the concret for the bases of lights and sign posts in parking lots or whatever. In response to Swez, I don't think the tube needs reinforcement at all. I've built 12" tubes with the actual tube having diameter of 14." the longest was ~27." The total airspace with my driver was roughly 2.25 cu ft. which for most non-competition single driver enclosures is in the larger end of the spectrum. Even at full volume there is very minimal vibration in the "walls" of the tube.
Of course, my tubes are also ported. A sealed tube may have pressure issues that cause the material to flex. Yet, as far as the material being cardboard, I feel there is no need for the fiberglass support, at least with a ported enclosure. The air simply spirals down the lenght of the tube and exits the port.
Oh well, I realize this argument is andectotal and only based on experience, but that's all I have :) I love tube enclosures and the bass is absolutely incredible. It would take a well built box enclosure perfectly matchin its sub to sound liek my tubes. As far as bazooka, they're made more for the midrange bass applciation, and the quality of their speakers are average...I have an older model cerwin vega 12" 400wRMS that's made to pound. With the air space in my tube it does just that. So I guess, at least with me, tubes most certainly have a place in car audio.
....hopefully this doesn't sound like an attack....
uochronos on 02/28/2004 02:23:13
ported tubes i hear can be great i have seen several ported tub enclosures made for alpine type R's they where all made out of plexiglass though... as far as cardboard i dont really know anything. for sealed though i think cardboard would com apart with a powerfull sub like a W7, A series, larger RE subd, and so on just because i have seen w7's break open a wood box at the seam because it wasnt screwed and reinforced well enough. i would really like to try a ported tube box for my type R's soemtime though from what i hear they make alot of differnce not sure though.
also if you really wanted a good tube to make a sub tub out of why not some big thick plactic pipe? anything 12-16" is harder to come by but not impossible at all use pipe caps to cap the ends then cut the whole in one for the speaker. seems to me as long as it was thick enough this would make a good sub tube.
dxmtussin on 02/28/2004 06:12:26
I have a 12" tube from walmart($50) 600w, with a 420 watt amp powering it, and I'm actually pretty pleased with how it sounds being a cheap ass sub and all. I feel all i need to do is change the sub to a better quality one and i'll be set. oh yeah it's my trunk too.
swez on 02/28/2004 11:05:58
El,
You make a very good point... a ported tube of that length is strong enough to support a medium duty sub. Ported allows more breathing of the tube and less flexing of the walls. The length mentioned, is short enough to not pose any real concerns.
My thoughts were geared toward things I have read about that others have tried as recommended by the manufacturer/designer of the tube sub. These are much longer tubes for HT applications and usually sealed. They mount upright in most cases as a column. Here, adding internal bracing is important according to the designer to inhibit resonances that would be present in longer tubes.
Also, for car installs, moisture in the trunk is often an issue. We all know how moisture affects cardboard right? That is the main purpose of glassing or using an epoxy based paint... a moisture barrier to block exterior condensation.
Your comments are welcome and no offense is taken...
Welcome to CK!
Swez
cplkittle on 02/28/2004 16:33:39
Question on how to port a tube enclosure.. could you suspend the tube with the driver inside a larger tube that is capped on the back?
Also, thinking of the old record players, would a gradual increase in diameter amplify the sound?
uochronos on 02/29/2004 03:18:06
i would think it would magnify the sound cplkittle but i would think in my opinion it would have to be really really accurate and designed right to get good SQ from it. not sure if it would make it loud enough to be worth trouble....
eldevioso on 03/2/2004 17:04:45
Cpl-
That's an interesting thought. For my tubes though I simply cut a 4" whole in the end opposite the driver and gorilla glued a 11" pvc pipe in space.
Swez-
Another interesting point. With a long tube I would imagine there would definitely need to be some sort of structural support. But for a MUCH longer tube you'd need a VERY powerful driver that would put out some serious pressure. In that case it would probably wreak havoc on my tube. As for the moisture in the trunk I never considered this. However, my tubes are carpeted so I'd imagine this helps with moisture, and the cardboard material is fairly resistant to moisture as it is sealed with some type of shiny material (since it is used to hold as a mold for concrete :)
Another reason I carpeted the tubes was, the idea that the carpet helps seals the sound in that much better considering the cardboard is only 1/8" thick. Do you think I gained anything via the 3m glue spray / carpet combination?
p.s. the gears are now turning on making some sort of LARGE scale, part asthetic but functional home theatre tubed subwoofer. . . I'll let you know if I try something.
Relax_The_Mind on 03/2/2004 17:46:03
tubes can be bent folded and shaped as long as the diameter remains the same and the driver would see it as one long tube. Much like the designs of home audio subs. Changing the diameter of a tube would actually change the speed of the air that passes through it, therefore changing the whole sound.
Air in a tube port) is not necessarily "pushed out" it is actually constantly being exchanged between inside and outside the box with all of the action being at the port of course. Much like sucking water up a straw then blowing it back into the glass but more at the rate of 100 times per second.
RTM
Pinch on 03/2/2004 20:42:51
Hey all! I've not posted in a while due to school and work (how dare they take time from my hobbies :), but I seem to have returned to a very interesting topic. In reading these posts, I began to think of similarities with other things in the industry. Fiber optics for example. Fiber optic cables are (as far as I've seen) round so that the signals bounce off the interior walls in a relatively lossless fashion. What if this principle were applied to the bass tube idea. I wonder what would happen if there was a relatively long tube with a sub in the middle. The end nearest the subs magnet would be sealed to provide the sub with some acoustic suspension. And the other end would be open (at least partially) to act as some sort of wave guide... Hmm, just thinking. Maybe it's nothing.
What if you compared a rectangular box to a tubular one with the same volume, what would the difference be?
I was thinking about this cause when I think of a sound wave, I think circles.
Anyone know why rectangular boxes are the norm?
Replies (23)
ttocs on 02/15/2004 17:36:46
it is easier to cut wood into squares, not circles.
Bazooka's are not a bad system. I had a pair back in the day and would use them again if the need arose. They tend to give off a less sound as they do not use drivers that are as good as alot of others available without a box.
cplkittle on 02/15/2004 23:42:13
Like ttocs said, it is all about the wood.
The first experiments in transmission lines were in tubes the same size as the driver. Round is actually ideal-think about it.. all musical instruments are round in shape. woodwinds, brass, strings, flutes, drums, cymbols, even chimes and 99% of all latin rhythm percussion instruments, The only thing I can think of that is not round is the xylophone, but the variations on that including the miramba and vibraphone have round resonators mounted below them.
This is a good question, and I don't know what difference it makes turning everything square, but I have seen alot of information that always points back to circles. for example, on the JL and Kicker websites, they recommend as close to square ports as possible if not round. Slotted ports do seriously dampen some frequencies-usually in octaves for example if your slot port dampens 10Hz, it will more than likely dampen all octaves above that on the same key (10, 20, 40, 80, 160, 320 etc).
SUBTROY1 on 02/16/2004 01:34:36
Here's a website that makes tube enclosures, not loaded. http://www.subtoms.com/index.html Unique. I had some Bazooka's before, they actually can put out some solid bass. I had 2 8's powered by a Punch 60, it shook my rear view and I remember it shaking a cassette tape in the front seat. They may not go as deep as some but they are pretty good nontheless and are good if you don't want to fill your trunk up with a huge box.
Troy
carbudgetaudio.com
erikcooper on 02/16/2004 23:55:15
You make could look into how much air space is in a bazooka tube as well and see if you could replace the bazooka driver with a more high quality one, you may be surprised what comes out...
kiaman on 02/17/2004 03:32:45
lol, my cdt 6.5's shake my rear view mirror....that dosnt take much to do.....but yea tubes are great enclousures......common place in high end HT systems.
kiaman on 02/17/2004 03:33:43
also...its not a box.....its an encolusure GRIN
(reffering to the title of this thread)
swez on 02/18/2004 19:36:25
Agreed, a tubular enclosure is a very good way to go for sub applications. The trick is to reinforce the tube well enough that it does not resonate at audio frequencies.
Tubes can be made of fiberglass, high impact plastics and other rigid materials. They tend to save space and if you get the throat of the tube large enough, 10's, 12's or a 15" woofer can be used. Just make sure you have the proper cf internally for a given sub .
Swez
PS The real plus side of a tube... no reflections from the back wall of the enclosure. It can also be ported if one so desires.
alanjlamore on 02/18/2004 21:05:43
I'm suprised that I've never seen any enclosures like these besides the bazooka's and now the subtoms from the website that SUBTROY1 provided (thanks by the way GRIN).
I've never been to an actual competition, so I don't know if it's more common there or not.
Does anyone know any other websites that has these?
I've searched a ton of search engines and couldn't find any.
Relax_The_Mind on 02/19/2004 04:26:15
Why not tubes? The general idea of the "round" design carrying on from the round and the general sub being round. Bass frequencies are generated from the moving of air inside the box.
The shape of the enclosure, in most cases, does not affect the
sound output of the subwoofer. The difference between box types such as multichamber enclosures, ported, and sealed are in the way they redirect the airflow coming from the sub. If you think about it, that is why subs dont do well parallel with to a wall because of the "standing waves" you get from the reflections.
Part of the sound even comes from the enclosure itself from the minor flexing of the different walls. Which is why you rarely see sealed boxes made our of iron or stainless steel and is one of the main reasons MDF is the most popular wood to use. Harder materials are generally used in the ported type enclosures.
Sound waves yes they have a cone effect when the sound emminates from the enclosure/subwoofer. A sub does NOT push air out in a perfect cone, circle, anything. Therefore coupling that with a tubular enclosure makes no real sense.
Dampening of frequencies from the ports is more related to port length rather than the shape of the port. Think of a pipe organ which uses that theory of odd and even octaves. All the pipes are generally the same size but different in length.
To answer your question...rectangular boxes are the norm because they maximize space usage in most cases whereas a tube would leave you with four unused areas if you think of them in a rectangular sense. Easier to build of course for the average box builder.
RTM
Once again did i make any sense?
swez on 02/19/2004 09:33:05
Pipe organ... same sized pipes? Come on, ever look at one up close? The sound tubes in a pipe organ are many different sizes, both length and diameter. The low end pipes are large in both diameter and in length. The high pitched pipes are short and small in diameter.
Basically, a pipe organ is like a huge grouping of flutes. Each is tuned to a specific frequency by length, diameter and amount of air space they contain. These are similar to speakers in some ways as each is precisely tuned to a given frequency. When air from the bellows is applied to a given pipe, (flute) it emits a whistle effect tone.
Think of pipes as pop bottles of differing sizes. Large bottles will produce low tones while small bottles produce high pitched tones. If you add fluids to them, it changes the pitch of the tone right?
Just bustin your chops in fun there RTM. But yeah, go to an old Church that has a big pipe organ and let someone show you how it works. Very impressive technology for such an old instrument... and the larger organs can produce notes below 28 Hz. That really shakes the pews dude!
Swez SMILE
PS If you ever go to Chicago, try to make a trip downtown to Moody Memorial Church. They have one of the most ellaborate organs in the Midwest. The guy that plays it most is named John Innus. Maybe he will give you a demonstration and some theory behind this magnificent pipe organ. You'll be amazed at the sound and skills that John has with this massive organ.
I listen to Moody radio a lot here in FL. They often have organ music as part of their praise and worship part of each program. Everytime I hear John whip up a strong wind with this machine... I get goose bumps. Awesome sounds dude!
Relax_The_Mind on 02/19/2004 17:39:53
Actually my statement was "All the pipes are generally the same size but different in length." I can explain why.
Ive studied pipe organs as well as other instruments. Older pipe organs and even the most elaborate ones depend on huge wind pumps and resivoirs (done manually with humans pulling big ropes and bellows to produce the air) for the bursts of air and the keys (stops,registers) actually release the air . The pipes yes are in different diameter but if you broke it down into an equation the actual differences in pitch and frequency. The higher the octave you want, the longer the pipe has to be. Each pipe will always only be able to play a certain tone but only at an odd or even octave depending on the length.
Taken from a Pipe Organ site.
"There are no keys or holes in the pipes of the organ to control the pitch. An organ pipe's pitch is determined by the length of the pipe."- http://nersp.nerdc.ufl.edu/~bodinew/
A pipe organ is a very good example to use for acoustics and physics (my fav subject).
If you ever get the chance to check out the many that are in the churches of new york city (you can try but a lot of the churches dont allow pictures....) I especially like the ones in St. Patricks Cathedral over 9,000 pipes... But yeh at family friends wedding up in nyc i forgot the church name...pipe organs give me chills down the spine. Really...reminds me of phantom of the opera type deal.
RTM
swez on 02/19/2004 21:00:34
Hummm, very interesting piece you linked me too. Thanks for sharing that one with me.
Yes, I have heard the St. Patrick's Cathedral organ on a radio broadcast where Paul Winter does his Winter Consort Series each year. The radio would hardly do it justice, but I could tell this was one special instrument.
Again, interesting read on Pipe Organ design and technology. Now they even use PVC resonator pipes I noted.
Swez
SUBTROY1 on 02/23/2004 02:27:54
Speaking of Phantom of the Opera, get a CD of it, some pretty impressive bass notes are in this tune. But back to the tubes, you can use SonoTube for subwoofer enclosures too. This is the tubes that are used to form concrete pillars. I think there are other brands of this type of thing you could pick up at Lowes, or Home Depot. I think the main thing is making sure that you have a solid mounting hole created, for the sub to be mounted to. I have an old set of Bazookas, now they look like they are made from PVC held together with some type of really wide tape that spans the length of the tube. The way they make them now may be different.
Troy
carbudgetaudio.com
swez on 02/23/2004 08:07:42
Yep, SonoTubes are a very good baseline material to work with prefab tubes. Comes in several diameters and you can just cut them to length you want. Probably a good idea to reinforce the outside with fiberglass to keep them strong an rigid as they are basically cardboard. Cheap too!
Swez
eldevioso on 02/28/2004 02:10:04
Here's my two cents:
I've built a few tube enclosures to date. Actually I've only built tube enclosures. I use a strong cardboard type material used as molds to pour the concret for the bases of lights and sign posts in parking lots or whatever. In response to Swez, I don't think the tube needs reinforcement at all. I've built 12" tubes with the actual tube having diameter of 14." the longest was ~27." The total airspace with my driver was roughly 2.25 cu ft. which for most non-competition single driver enclosures is in the larger end of the spectrum. Even at full volume there is very minimal vibration in the "walls" of the tube.
Of course, my tubes are also ported. A sealed tube may have pressure issues that cause the material to flex. Yet, as far as the material being cardboard, I feel there is no need for the fiberglass support, at least with a ported enclosure. The air simply spirals down the lenght of the tube and exits the port.
Oh well, I realize this argument is andectotal and only based on experience, but that's all I have :) I love tube enclosures and the bass is absolutely incredible. It would take a well built box enclosure perfectly matchin its sub to sound liek my tubes. As far as bazooka, they're made more for the midrange bass applciation, and the quality of their speakers are average...I have an older model cerwin vega 12" 400wRMS that's made to pound. With the air space in my tube it does just that. So I guess, at least with me, tubes most certainly have a place in car audio.
....hopefully this doesn't sound like an attack....
uochronos on 02/28/2004 02:23:13
ported tubes i hear can be great i have seen several ported tub enclosures made for alpine type R's they where all made out of plexiglass though... as far as cardboard i dont really know anything. for sealed though i think cardboard would com apart with a powerfull sub like a W7, A series, larger RE subd, and so on just because i have seen w7's break open a wood box at the seam because it wasnt screwed and reinforced well enough. i would really like to try a ported tube box for my type R's soemtime though from what i hear they make alot of differnce not sure though.
also if you really wanted a good tube to make a sub tub out of why not some big thick plactic pipe? anything 12-16" is harder to come by but not impossible at all use pipe caps to cap the ends then cut the whole in one for the speaker. seems to me as long as it was thick enough this would make a good sub tube.
dxmtussin on 02/28/2004 06:12:26
I have a 12" tube from walmart($50) 600w, with a 420 watt amp powering it, and I'm actually pretty pleased with how it sounds being a cheap ass sub and all. I feel all i need to do is change the sub to a better quality one and i'll be set. oh yeah it's my trunk too.
swez on 02/28/2004 11:05:58
El,
You make a very good point... a ported tube of that length is strong enough to support a medium duty sub. Ported allows more breathing of the tube and less flexing of the walls. The length mentioned, is short enough to not pose any real concerns.
My thoughts were geared toward things I have read about that others have tried as recommended by the manufacturer/designer of the tube sub. These are much longer tubes for HT applications and usually sealed. They mount upright in most cases as a column. Here, adding internal bracing is important according to the designer to inhibit resonances that would be present in longer tubes.
Also, for car installs, moisture in the trunk is often an issue. We all know how moisture affects cardboard right? That is the main purpose of glassing or using an epoxy based paint... a moisture barrier to block exterior condensation.
Your comments are welcome and no offense is taken...
Welcome to CK!
Swez
cplkittle on 02/28/2004 16:33:39
Question on how to port a tube enclosure.. could you suspend the tube with the driver inside a larger tube that is capped on the back?
Also, thinking of the old record players, would a gradual increase in diameter amplify the sound?
uochronos on 02/29/2004 03:18:06
i would think it would magnify the sound cplkittle but i would think in my opinion it would have to be really really accurate and designed right to get good SQ from it. not sure if it would make it loud enough to be worth trouble....
eldevioso on 03/2/2004 17:04:45
Cpl-
That's an interesting thought. For my tubes though I simply cut a 4" whole in the end opposite the driver and gorilla glued a 11" pvc pipe in space.
Swez-
Another interesting point. With a long tube I would imagine there would definitely need to be some sort of structural support. But for a MUCH longer tube you'd need a VERY powerful driver that would put out some serious pressure. In that case it would probably wreak havoc on my tube. As for the moisture in the trunk I never considered this. However, my tubes are carpeted so I'd imagine this helps with moisture, and the cardboard material is fairly resistant to moisture as it is sealed with some type of shiny material (since it is used to hold as a mold for concrete :)
Another reason I carpeted the tubes was, the idea that the carpet helps seals the sound in that much better considering the cardboard is only 1/8" thick. Do you think I gained anything via the 3m glue spray / carpet combination?
p.s. the gears are now turning on making some sort of LARGE scale, part asthetic but functional home theatre tubed subwoofer. . . I'll let you know if I try something.
Relax_The_Mind on 03/2/2004 17:46:03
tubes can be bent folded and shaped as long as the diameter remains the same and the driver would see it as one long tube. Much like the designs of home audio subs. Changing the diameter of a tube would actually change the speed of the air that passes through it, therefore changing the whole sound.
Air in a tube port) is not necessarily "pushed out" it is actually constantly being exchanged between inside and outside the box with all of the action being at the port of course. Much like sucking water up a straw then blowing it back into the glass but more at the rate of 100 times per second.
RTM
Pinch on 03/2/2004 20:42:51
Hey all! I've not posted in a while due to school and work (how dare they take time from my hobbies :), but I seem to have returned to a very interesting topic. In reading these posts, I began to think of similarities with other things in the industry. Fiber optics for example. Fiber optic cables are (as far as I've seen) round so that the signals bounce off the interior walls in a relatively lossless fashion. What if this principle were applied to the bass tube idea. I wonder what would happen if there was a relatively long tube with a sub in the middle. The end nearest the subs magnet would be sealed to provide the sub with some acoustic suspension. And the other end would be open (at least partially) to act as some sort of wave guide... Hmm, just thinking. Maybe it's nothing.
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