Its called an Aperiodic Bi-Chamber, supposedly it has the massive 30 - 45hz wangage of a typical 30 - 33hz tune box, but the high end extension of a sealed box. A "best of both worlds" type of thing.
Does anyone have experience with these?
From what I hear its basically a snail shell but modified.
swez and victor (and a few others i cant think of off the top of my head so sorry if i dont mention your name) im sure you can help me out with this
someone i know is trying to figure it out aswell and has designed a box already for an atlas 15
32.25" x 17" x 25", External Dimensions
Divider Centered at 12.875" Starting from Left Side of Enclosure.
15.5" x 3" x 18.5", Port Dimensions
Internal Port Board is 14.625" Long, Exactly 3" from Left Chamber Port Wall
2.407 and 4.05 Gross Volumes
4.5 Cubic Foot NET Volume, Tuned to 33hz"
Replies (12)
lessismorespl on 07/2/2005 03:35:00
I remember seeing a topic on Termpro about this enclosure, however the site is down right now, I will get you a URL as soon as it is back up. There were some real world class competitors talking about this enclosure.
swez on 07/2/2005 09:49:04
I found a few videos on this cutting edge design for those that are interested. If one is on a low budget, wants plenty of deep, low bass that is clean and accurated at above averge SPL, these links will probably get your attention.
http://www.diyaudio.com/forums/showthread/t-22103.html
It's not the amp(s), its not the subs... it's the enclosure design that makes it all possible. A 25 Hz test tone and then some music with butt kickin bass. I am impressed with the videos and comments of the people in the videos. Wait til ya see the drivers he used for this system.
Swez
BgDustin4 on 07/2/2005 20:27:17
all i can say is wow!!! Any one know how to make this box
Victor on 07/2/2005 22:29:38
Snail shell.. hmmm..
Lets make one thing about ABC's clear they are called Aperiodic Bi-chamber enclosures.. But just called,
In theory they are Quasi Eight order Series tuned Dual reflex bandpass boxes..
Digest it...hehe..
This one is going to be a long one...
Sound acoustics, the understanding of propogation of sound waves, in different mediums, interaction of sound waves with particles, mutual interaction of number of sound waves, reflection and refraction of sound waves, behaviour of soundwaves in different environments and surroundings. Not to forget Human perception and sense of monitoring and translating the sound waves.
I will have to write a whole lot on these subjects to explain you how all these different kind of enclosures are derived... which i definitely will not....
But to explain it to you in short. The one you are looking at will be a BIG BIG box , Very hard to tune and fabricate. There are all the possibilities of going wrong here. A faliure is bound to happen. not trying to discourage you .. just a simple warning..
You may want to see this...
http://www.cardomain.com/ride/639734/10
http://www.the12volt.com/caraudio/boxes6.asp ( scroll down to see the diagram of the enclosure we are talking about ).
And this is how you can make it, if you choose to.
http://www.diysubwoofers.org/prt/dual_chamber.htm
One more thing, All bandpass enclosures ( this one IS A BANDPASS ) of orders higher than 4th will show out of band noise, this cna be solved by a simple bandpass notch filter. Let me know if u decide to make the box, i can tell u how to make the notch filter.
Hope that helps...
Victor..
ssallstar598 on 07/3/2005 02:15:06
i am interested in building this.... im currently talking to someone i know who used a modified version of an ABC enclosure w/ an Xsite 8 inch driver w/ 150 watts and scored low 140s on the TL w/ it.... it was in a honda CRX and the same box was 2 dB louder in an eclipse
ssallstar598 on 07/3/2005 08:20:55
http://forum.sounddomain.com/forum/ultimatebb.cgi?ubb=get_topic;f=11;t=064764
nice link w/ pics of the inside of the box... its a modified version of the box.... has the sub firing outside the box instead of inside....
anyways i am contempt in designing and building this box
ive found the optimum specs for my tempest, just gotta change it into dimensions (which im not very good at....)
4.0 cf net with 4" diameter 16" long ports tuned to 30 hz
so i would need to figure out the amount of cf that the ports take up (i will be using aeroports for minimal port noise) the tempest takes up 5 liters.... (thats what adire says on their website)
w/o the known CF of the tempest and aeroports my volumes are
1.33 cf (chamber w/ no driver)
2.66 cf (chamber w/ driver)
correct me if im wrong
Victor on 07/3/2005 10:54:07
You are correct about the tuning , the port calculations and the enclosure volume.
The volume of a port can be calculated by the formula of a cylinder..
3.14 x radius squared x height.
.
A suggesstion.... , If you use the volume of an EBS rather than the optimum volume of a Ported box thenyou will get higher SPL and can go much lower in Frequency.
Victor...
ssallstar598 on 07/3/2005 13:29:12
could you explain EBS?
Victor on 07/3/2005 15:04:42
EBS- Extended Bass Shelf.
This is only one of the various different types of vented alignments which are possible and follows many of the same characteristics of vented enclosures.
The idea is to intentionally design the enclosure to be 125-175% larger than the optimal calculated volume and then tune the enclosure much lower than optimal as well.
The result is a significant amount of extended low frequency response. When the response curve is simulated, a visible "shelf" can be seen in the curve just above the tuning frequency before it sharply rolls off.
The EBS alignment will maintain much lower cone excursion at frequencies near Fb than is possible with the QB3 alignment. This can be very important for high power systems."
Advantages
Extended low frequency response down into the teens.
Subsonic earth shattering bass response.
Increased efficiency at the lower frequencies (below 25 Hz) but decreased efficiency at higher frequencies (above 30 Hz).
This is a rough figure since many different combinations can be designed to yield specific results.
In general, low frequency is extended and efficiency increased at the expense of reduced efficiency at higher frequencies.
Disadvantages
Cut-off rate can be as high 36 dB/octave below fB.
Transient response is degraded as a result of this.
However it may be argued that because the tuning frequency is so low, that is it far enough out of normal operating range that it may be considered a negligible downside.
The enclosure size is huge. Anywhere from 5-15 cubic feet depending on the size of the driver being used. Power handling capability of driver is reduced anywhere from 25-50%.
Driver may reach Xmax sooner above fB even if it never reaches Xmax right at or below fB. Lack of real presence.
Lack of kick or punch. The overall impact of the bass is much softer. Signals between 40 and 60 Hz are significantly reduced.
Harder to "sell" because most people are more receiving to a pronounced upper bass response rather than an incredibly low and deep bass response .
It takes 4 times as much power (as well as moving air) to make 20 Hz sound as loud as 40 Hz.
Best Applications
Where the truly deepest of all heavenly deep bass is desired. For drivers with a large Xmax and the ability to consume large amounts of power. For drivers whose T/S parameters dictate an optimal enclosure size that's smaller than what the designer wants to build. Large Home Theaters and varying kinds of music with heavy bass tracks would take the best advantage of this enclosure alignment.
Although when an EBS alignment volume of enclosure is used in an ABC enclosure the upper region of Bass frequencies can be notably louder and the transient response also improves when compared to EBS along with the low frequency boost.
The use of a variable Subsonic filter which cuts off everything below the tuning frequency is a must.
Hope that helps..
Victor...
ssallstar598 on 07/6/2005 21:45:34
victor - i was looking into the Quasi Eight order Series tuned Dual reflex bandpass boxes w/ someone i know who built a few.... this is what he said (i got him mad by saying ABC box lol)
The ABC name aggrivates me. It's real name is DCR, or Dual Chamber Reflex, which literally explains its a ported box with 2 chambers! It is in no way a bandpass in any shape or form. For it to be a bandpass, you must have an enclosure on each side of the woofer, period. You don't have that with a DCR. Bandpass is amazing, if done correctly, and its usually not. Bandpass got a bad name from prefab boxes. The worlds loudest vehicles right now are using a 4th order bandpass, and bandpass can sound good if you do it with a good design with the right woofer. Bandpass is very woofer picky and very dependant on the rest of whats going on with the enclosure. If you change 1 thing on 1 side, it changes how it acts on the other side too.
im kinda lost now...... is the box a bandpass or not?
Victor on 07/7/2005 04:17:10
I agree.. It was a mistake on my side...The only difference between the Quasi 8thorder Dual reflex bandpass and the ABC is that in the bandpass the woofer faces inside the box into the 2nd chamber while in ABC the sub faces outside.
It is not a small difference because in the bandpass soundwaves emerging from both the sides of the cone are modified but in the ABC only the sound emerging from the rear is treated..
The guy was right to get mad at you.. Sorry for the confusion... It was a silly mistake on my side.
Victor..
here are the links to the plans of both the enclosures to see the difference.. I know its a dumb mistake but afterall i am prone to mistakes to as everyother human.
See the picture on the left side http://www.diysubwoofers.org/prt/dual_chamber.htm
Scroll down to the Quasi 8th order dual reflex
http://www.the12volt.com/caraudio/boxes6.asp#1
ssallstar598 on 07/7/2005 08:31:43
o its not a big deal.... i was actually wondering why 1 diagram had it facing inside and the other facing outside........
Does anyone have experience with these?
From what I hear its basically a snail shell but modified.
swez and victor (and a few others i cant think of off the top of my head so sorry if i dont mention your name) im sure you can help me out with this
someone i know is trying to figure it out aswell and has designed a box already for an atlas 15
32.25" x 17" x 25", External Dimensions
Divider Centered at 12.875" Starting from Left Side of Enclosure.
15.5" x 3" x 18.5", Port Dimensions
Internal Port Board is 14.625" Long, Exactly 3" from Left Chamber Port Wall
2.407 and 4.05 Gross Volumes
4.5 Cubic Foot NET Volume, Tuned to 33hz"
Replies (12)
lessismorespl on 07/2/2005 03:35:00
I remember seeing a topic on Termpro about this enclosure, however the site is down right now, I will get you a URL as soon as it is back up. There were some real world class competitors talking about this enclosure.
swez on 07/2/2005 09:49:04
I found a few videos on this cutting edge design for those that are interested. If one is on a low budget, wants plenty of deep, low bass that is clean and accurated at above averge SPL, these links will probably get your attention.
http://www.diyaudio.com/forums/showthread/t-22103.html
It's not the amp(s), its not the subs... it's the enclosure design that makes it all possible. A 25 Hz test tone and then some music with butt kickin bass. I am impressed with the videos and comments of the people in the videos. Wait til ya see the drivers he used for this system.
Swez
BgDustin4 on 07/2/2005 20:27:17
all i can say is wow!!! Any one know how to make this box
Victor on 07/2/2005 22:29:38
Snail shell.. hmmm..
Lets make one thing about ABC's clear they are called Aperiodic Bi-chamber enclosures.. But just called,
In theory they are Quasi Eight order Series tuned Dual reflex bandpass boxes..
Digest it...hehe..
This one is going to be a long one...
Sound acoustics, the understanding of propogation of sound waves, in different mediums, interaction of sound waves with particles, mutual interaction of number of sound waves, reflection and refraction of sound waves, behaviour of soundwaves in different environments and surroundings. Not to forget Human perception and sense of monitoring and translating the sound waves.
I will have to write a whole lot on these subjects to explain you how all these different kind of enclosures are derived... which i definitely will not....
But to explain it to you in short. The one you are looking at will be a BIG BIG box , Very hard to tune and fabricate. There are all the possibilities of going wrong here. A faliure is bound to happen. not trying to discourage you .. just a simple warning..
You may want to see this...
http://www.cardomain.com/ride/639734/10
http://www.the12volt.com/caraudio/boxes6.asp ( scroll down to see the diagram of the enclosure we are talking about ).
And this is how you can make it, if you choose to.
http://www.diysubwoofers.org/prt/dual_chamber.htm
One more thing, All bandpass enclosures ( this one IS A BANDPASS ) of orders higher than 4th will show out of band noise, this cna be solved by a simple bandpass notch filter. Let me know if u decide to make the box, i can tell u how to make the notch filter.
Hope that helps...
Victor..
ssallstar598 on 07/3/2005 02:15:06
i am interested in building this.... im currently talking to someone i know who used a modified version of an ABC enclosure w/ an Xsite 8 inch driver w/ 150 watts and scored low 140s on the TL w/ it.... it was in a honda CRX and the same box was 2 dB louder in an eclipse
ssallstar598 on 07/3/2005 08:20:55
http://forum.sounddomain.com/forum/ultimatebb.cgi?ubb=get_topic;f=11;t=064764
nice link w/ pics of the inside of the box... its a modified version of the box.... has the sub firing outside the box instead of inside....
anyways i am contempt in designing and building this box
ive found the optimum specs for my tempest, just gotta change it into dimensions (which im not very good at....)
4.0 cf net with 4" diameter 16" long ports tuned to 30 hz
so i would need to figure out the amount of cf that the ports take up (i will be using aeroports for minimal port noise) the tempest takes up 5 liters.... (thats what adire says on their website)
w/o the known CF of the tempest and aeroports my volumes are
1.33 cf (chamber w/ no driver)
2.66 cf (chamber w/ driver)
correct me if im wrong
Victor on 07/3/2005 10:54:07
You are correct about the tuning , the port calculations and the enclosure volume.
The volume of a port can be calculated by the formula of a cylinder..
3.14 x radius squared x height.
.
A suggesstion.... , If you use the volume of an EBS rather than the optimum volume of a Ported box thenyou will get higher SPL and can go much lower in Frequency.
Victor...
ssallstar598 on 07/3/2005 13:29:12
could you explain EBS?
Victor on 07/3/2005 15:04:42
EBS- Extended Bass Shelf.
This is only one of the various different types of vented alignments which are possible and follows many of the same characteristics of vented enclosures.
The idea is to intentionally design the enclosure to be 125-175% larger than the optimal calculated volume and then tune the enclosure much lower than optimal as well.
The result is a significant amount of extended low frequency response. When the response curve is simulated, a visible "shelf" can be seen in the curve just above the tuning frequency before it sharply rolls off.
The EBS alignment will maintain much lower cone excursion at frequencies near Fb than is possible with the QB3 alignment. This can be very important for high power systems."
Advantages
Extended low frequency response down into the teens.
Subsonic earth shattering bass response.
Increased efficiency at the lower frequencies (below 25 Hz) but decreased efficiency at higher frequencies (above 30 Hz).
This is a rough figure since many different combinations can be designed to yield specific results.
In general, low frequency is extended and efficiency increased at the expense of reduced efficiency at higher frequencies.
Disadvantages
Cut-off rate can be as high 36 dB/octave below fB.
Transient response is degraded as a result of this.
However it may be argued that because the tuning frequency is so low, that is it far enough out of normal operating range that it may be considered a negligible downside.
The enclosure size is huge. Anywhere from 5-15 cubic feet depending on the size of the driver being used. Power handling capability of driver is reduced anywhere from 25-50%.
Driver may reach Xmax sooner above fB even if it never reaches Xmax right at or below fB. Lack of real presence.
Lack of kick or punch. The overall impact of the bass is much softer. Signals between 40 and 60 Hz are significantly reduced.
Harder to "sell" because most people are more receiving to a pronounced upper bass response rather than an incredibly low and deep bass response .
It takes 4 times as much power (as well as moving air) to make 20 Hz sound as loud as 40 Hz.
Best Applications
Where the truly deepest of all heavenly deep bass is desired. For drivers with a large Xmax and the ability to consume large amounts of power. For drivers whose T/S parameters dictate an optimal enclosure size that's smaller than what the designer wants to build. Large Home Theaters and varying kinds of music with heavy bass tracks would take the best advantage of this enclosure alignment.
Although when an EBS alignment volume of enclosure is used in an ABC enclosure the upper region of Bass frequencies can be notably louder and the transient response also improves when compared to EBS along with the low frequency boost.
The use of a variable Subsonic filter which cuts off everything below the tuning frequency is a must.
Hope that helps..
Victor...
ssallstar598 on 07/6/2005 21:45:34
victor - i was looking into the Quasi Eight order Series tuned Dual reflex bandpass boxes w/ someone i know who built a few.... this is what he said (i got him mad by saying ABC box lol)
The ABC name aggrivates me. It's real name is DCR, or Dual Chamber Reflex, which literally explains its a ported box with 2 chambers! It is in no way a bandpass in any shape or form. For it to be a bandpass, you must have an enclosure on each side of the woofer, period. You don't have that with a DCR. Bandpass is amazing, if done correctly, and its usually not. Bandpass got a bad name from prefab boxes. The worlds loudest vehicles right now are using a 4th order bandpass, and bandpass can sound good if you do it with a good design with the right woofer. Bandpass is very woofer picky and very dependant on the rest of whats going on with the enclosure. If you change 1 thing on 1 side, it changes how it acts on the other side too.
im kinda lost now...... is the box a bandpass or not?
Victor on 07/7/2005 04:17:10
I agree.. It was a mistake on my side...The only difference between the Quasi 8thorder Dual reflex bandpass and the ABC is that in the bandpass the woofer faces inside the box into the 2nd chamber while in ABC the sub faces outside.
It is not a small difference because in the bandpass soundwaves emerging from both the sides of the cone are modified but in the ABC only the sound emerging from the rear is treated..
The guy was right to get mad at you.. Sorry for the confusion... It was a silly mistake on my side.
Victor..
here are the links to the plans of both the enclosures to see the difference.. I know its a dumb mistake but afterall i am prone to mistakes to as everyother human.
See the picture on the left side http://www.diysubwoofers.org/prt/dual_chamber.htm
Scroll down to the Quasi 8th order dual reflex
http://www.the12volt.com/caraudio/boxes6.asp#1
ssallstar598 on 07/7/2005 08:31:43
o its not a big deal.... i was actually wondering why 1 diagram had it facing inside and the other facing outside........
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